diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,3 @@
+## Ormolu 0.0.1.0
+
+* Initial release.
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,64 @@
+# Contributing
+
+Issues (bugs, feature requests or otherwise feedback) may be reported in
+[the GitHub issue tracker for this project][issues]. Pull requests are also
+welcome.
+
+When contributing to this repository, please first discuss the change you
+wish to make via an issue, unless it's entirely trivial (typo fixes, etc.).
+If there is already an issue that describes the change you have in mind,
+comment on it indicating that you're going to work on that. This way we can
+avoid the situation when several people work on the same thing.
+
+Please make sure that all non-trivial changes are described in commit
+messages and PR descriptions.
+
+## What to hack on?
+
+* [Fixing bugs][bugs]. This is the main focus right now.
+
+### Testing
+
+Testing has been taken good care of and now it amounts to just adding
+examples under `data/examples`. Each example is a pair of files:
+`<example-name>.hs` for input and `<example-name>-out.hs` for corresponding
+expected output.
+
+Testing is performed as following:
+
+* Given snippet of source code is parsed and pretty-printed.
+* The result of printing is parsed back again and the AST is compared to the
+  AST obtained from the original file. They should match.
+* The output of printer is checked against the expected output.
+* Idempotency property is verified: formatting already formatted code
+  results in exactly the same output.
+
+Examples can be organized in sub-directories, see the existing ones for
+inspiration.
+
+Please note that we try to keep individual files at most 25 lines long
+because otherwise it's hard to figure out want went wrong when a test fails.
+
+## CI
+
+We use Circle CI. Some outside contributors may have problems, as in, CI
+won't run for PRs opened from forks with “unauthorized” errors. In that case
+the best we can do is to add you as a contributor or to restart your build
+manually.
+
+If you have been added as a contributor but the builds still do not start,
+try clicking
+
+```
+User settings -> Account integrations -> Refresh permissions
+```
+
+in Circle CI app.
+
+## Formatting
+
+Use `format.sh` script to format Ormolu with current version of Ormolu. If
+Ormolu is not formatted like this, the CI will fail.
+
+[issues]: https://github.com/tweag/ormolu/issues
+[bugs]: https://github.com/tweag/ormolu/issues?q=is%3Aissue+is%3Aopen+label%3Abug
diff --git a/DESIGN.md b/DESIGN.md
new file mode 100644
--- /dev/null
+++ b/DESIGN.md
@@ -0,0 +1,407 @@
+# Ormolu
+
+*This document represents our discussions and plans at early stages of
+development, it is no longer being updated.*
+
+* [Analysis of the existing solutions](#analysis-of-the-existing-solutions)
+    * [Brittany](#brittany)
+    * [Hindent](#hindent)
+    * [Stylish Haskell](#stylish-haskell)
+    * [Haskell formatter](#haskell-formatter)
+* [Proposed design](#proposed-design)
+    * [Parsing](#parsing)
+    * [CPP](#cpp)
+    * [Printing](#printing)
+    * [Configuration](#configuration)
+    * [Handling of language extensions](#handling-of-language-extensions)
+    * [Testing](#testing)
+    * [Functionality of executable](#functionality-of-executable)
+    * [Why not contribute to/fork Hindent or Brittany?](#why-not-contribute-tofork-hindent-or-brittany)
+* [Examples](#examples)
+
+This document describes design of a new formatter for Haskell source code.
+It also includes recommendations for future implementers.
+
+We set for the following goals (mostly taken from
+[brittany](https://github.com/lspitzner/brittany)):
+* Preserve the meaning of the formatted functions;
+* Make reasonable use of screen space;
+* Use linear space and computation time on the size of the input;
+* Preserve comments;
+* Be idempotent.
+
+## Analysis of the existing solutions
+
+In order to design a new formatter we need to study the existing solutions
+so we can borrow the good bits and avoid making the same mistakes.
+
+### Brittany
+
+[Brittany][brittany] builds on top of [`ghc-exactprint`][ghc-exactprint]—a
+library that uses parser of GHC itself for parsing and thus it guarantees
+that at least parsing phase is bug-free (which is admittedly the cause of
+majority of bugs in other projects, see below).
+
+After parsing, Haskell AST and a collection of annotations are available.
+The annotations are there because Haskell AST doesn't provide enough
+information to reconstruct source code (for example it doesn't include
+comments). The AST and the annotations are converted into a `BriDoc` value.
+A `BriDoc` value is a document representation like the `Doc` from the
+[pretty][pretty-doc] or the [wl-pprint][wl-pprint-doc] libraries.
+
+Brittany implements its own document type in an attempt to find a
+satisfactory rendering of the source code that fits a page-width
+constraint. Because of this, a `BriDoc` value represents a collection
+of many candidate layouts (i.e. renderings) of the source code.
+
+This collection is pruned until it contains a single layout. The
+structure of the chosen layout is then adjusted to leave it in a
+form which can be easily traversed to produce the final rendering.
+
+Brittany invests the majority of its implementation to manage
+the `BriDoc` values. Given that the amount of possible layouts is
+exponential, the representation is clever enough to fit them in
+linear space. There are multiple ways to build a `BriDoc`, not all
+of which fit in linear space. So care is necessary to keep memory
+bounded.
+
+The compexities of the `BriDoc` structure, together with the lack of
+documentation, make Brittany at least challenging to maintain.
+
+### Hindent
+
+[Hindent][hindent] uses [`haskell-src-exts`][haskell-src-exts] for parsing
+like all older projects. `haskell-src-exts` does not use parser of GHC
+itself, and is a source of endless parsing bugs. `Hindent` is affected by
+these upstream issues as well as Stylish Haskell and Haskell formatter (see
+below). This already makes all these projects unusable with some valid
+Haskell source code, but let's continue studying Hindent anyway.
+
+Hindent is quite different from Brittany in the sense that it does not
+attempt to build a document representation to render
+afterwards, instead it just prints the parsed code straight away. This means
+that the 70-80% of what the code does is a printing traversal.
+
+Hindent code is easier to read and debug. Pretty-printing functions are
+very straightforward. If there is a bug (in pretty-printer, not in parser
+which Hindent cannot control), it's easy to fix AFAIU.
+
+Hindent is also notable for its ability to handle CPP and inputs that do not
+constitute complete modules. It splits input stream into so-called “code
+blocks” recognizing CPP macros and then only pretty-prints “normal code”
+without touching CPP directives. After that CPP is inserted between
+pretty-printed blocks of source code. The approach fails when CPP breaks
+code in such a way that separate blocks do not form valid Haskell
+expressions, see
+[this](https://github.com/commercialhaskell/hindent/issues/383) for example.
+
+Looking at the bug tracker there are many bugs. Part of them is because of
+the use of `haskell-src-exts`, the other part is because the maintainer
+doesn't care (anymore?) and doesn't fix them. Well it's as simple as that,
+with any sort of commercial backing the bugs in pretty printer would be
+fixed long time ago.
+
+### Stylish Haskell
+
+[Stylish Haskell][stylish-haskell] also uses `haskell-src-exts` and suffers
+from the same upstream problems. I haven't studied the transformations it
+performs, but it looks like it transforms the parsed source code partially
+by manipulating AST and partially by manipulating raw text (e.g. to drop
+trailing whitspace from each line). CPP Macros are just filtered out
+silently as a preprocessing step before feeding the code to
+`haskell-src-exts`.
+
+Stylish Haskell is not so invasive as the other formatters and most reported
+bugs are about parsing issues and CPP. As I understand it, people mostly use
+it to screw their import lists.
+
+### Haskell formatter
+
+[Haskell formatter][haskell-formatter] is an older project that didn't get
+much traction. It also uses `haskell-src-ext` and also tries to do
+manipulations on the parsed AST. The issue tracker doesn't have many issues
+probably because it never got popular enough (only 15 stars on GitHub). All
+the issues are about upstream problems with `haskell-src-exts`.
+
+## Proposed design
+
+This section describes a solution that combines all the good things from the
+projects above.
+
+### Parsing and CPP
+
+It is clear that `ghc-exactprint` is better than `haskell-src-exts`, so we
+should use that. If we go with `ghc-exactprint` though, we'll need to
+specify which parser to use, e.g. the parser that parses whole module or the
+one which parsers declarations/expressions/etc. It seems that in general
+it's better to use the parser for modules because it should work with all
+input files containing complete modules, while with other parsers it's
+impossible to guess what they'll be called on.
+
+### CPP
+
+Formatting a module which uses CPP directives won't be supported. Instead,
+we hope for a solution to replace CPP to do conditional compilation.
+
+There are the following challenges when formatting a module with CPP:
+
+* GHC parser won't accept anything but a valid, complete module. Therefore,
+  formatting the Haskell code between CPP directives is not an option.
+
+* Ignoring the CPP directives and formatting the Haskell code can change
+  its meaning. An example follows.
+
+Let's suppose that we want to format the following program:
+
+```
+$ cat test.hs
+{-# LANGUAGE CPP #-}
+main = print (g && f1)
+  where
+        f1 = h
+          where
+            h = True
+#ifdef C1
+g = g1
+  where
+    g1 = g2
+      where
+        g2 = False
+#else
+        g = True
+#endif
+
+#ifndef C1
+g = False
+#endif
+
+$ runhaskell test.hs
+True
+```
+
+At the time of this writing, formatting this program with Hindent
+produces the same output we would get if the CPP directives were
+considered comments:
+
+```
+$ hindent --version
+hindent 5.2.7
+
+$ hindent test.hs
+
+$ cat test.hs
+{-# LANGUAGE CPP #-}
+
+main = print (g && f1)
+  where
+    f1 = h
+      where
+        h = True
+#ifdef C1
+g = g1
+  where
+    g1 = g2
+      where
+        g2 = False
+#else
+        g = True
+#endif
+
+#ifndef C1
+g = False
+#endif
+
+$ runhaskell test.hs
+False
+```
+
+Running the formatter causes the output of the program to change
+from `True` to `False` when `C1` is not defined.
+
+A solution could be to make the formatter more careful with CPP
+directives, constraining how directives can be inserted in Haskell
+code to avoid changing the meaning by reformatting. But
+this would introduce additional complexity, and the problem would
+need to be solved repeteadly for every tool out there which wants
+to parse Haskell modules. If CPP is replaced with some language
+extension or mechanism to do conditional compilation, all tools
+will benefit from it.
+
+Therefore, CPP won't be supported. If the CPP extension
+is enabled, we should signal an error right away.
+
+### Printing
+
+Just pretty-printing code (following the approach of Hindent) seems sane. It
+is straightforward and when complemented with enough tests (see the section
+about testing below), it should work all right.
+
+Implementation can be just a `Reader` monad producing something like text
+builder. The context of `Reader` can store current indentation and
+configuration options.
+
+As the pretty-printing library we can use [`Outputable`][outputable] (and
+`SDoc`) from the [`ghc`][ghc] package itself (at least for pretty-printing
+basic things like floating point literals and the like). The benefit is that
+AST components that we'll want to print are already instances of
+`Outputable`, so we'll get correct renderings for free.
+
+In order to keep the output of the formatter simple, fast and correct,
+we introduce the following rule. The pretty-printing code can be in
+control of every formatting choice, except for two, which are left to
+the programmer:
+
+1. location of comments (comments are going to be attached to specific
+   syntactic entities, so moving an entity will move its comment too),
+2. line breaking.
+
+Regarding (2), the idea is that given any syntactic entity, the programmer
+has a choice:
+
+1. write it on one line, or
+2. write it on two lines or more.
+
+If (1), then everything is kept in one line. If (2), i.e. a line break appears
+somewhere in the concrete syntax tree (CST), then additional line breaks are
+introduced everywhere possible in parent nodes, *but not in any sibling or
+children nodes*.
+
+Examples:
+
+```haskell
+-- Stays as is.
+data T = A | B
+
+data T
+  = A | B
+-- Is reformatted to:
+data T
+  = A
+  | B
+
+-- Stays as is.
+map :: (a -> b) -> [a] -> [b]
+
+foldr :: (a -> b -> b) ->
+  b -> [a] -> [b]
+-- Is reformatted to:
+foldr ::
+  (a -> b -> b) ->
+  b ->
+  [a] ->
+  [b]
+
+t = let x = foo bar
+                      baz
+  in foo bar baz
+-- Is reformatted to:
+t =
+  let x =
+        foo
+          bar
+          baz
+   in foo far baz
+```
+
+Crucially, no effort is made to fit within reasonable line lengths. That's
+up to the programmer. Style will still be consistent for everyone in every
+other aspect, and that's what counts.
+
+### Configuration
+
+We are not allowing to configure any aspect of the formatter. A module
+might be used in multiple projects, and we prefer to have it formatted
+the same in all of them.
+
+See this [this
+post][hindent-5-blog] by Chris Done (the author of Hindent) which says that
+as long as the default style is conventional and good it doesn't really
+matter how code gets formatted. Consistency is more important.
+
+### Handling of language extensions
+
+Some language extensions affect how parsing is done. We are going to deal
+with those in two ways:
+
+* When language pragmas are present in source file, we must parse them
+  before we run the main parser (I guess) and they should determine how the
+  main parsing will be done.
+* There also should be configuration file that may enable other language
+  extensions to be used on all files.
+* Later we could try to locate Cabal files and fetch the list of extensions
+  that are enabled by default from there.
+
+### Testing
+
+It should be possible to add tests incrementally as we develop
+pretty-printing code and new issues are discovered. For each Haskell
+module that we want to test, we perform the following steps:
+
+1. Given input snippet of source code parse it and pretty print it.
+2. Parse the result of pretty-printing again and make sure that AST is the
+   same as AST of original snippet module span positions. We could make
+   this part of a self-check in the formatter.
+3. Check the output against expected output. Thus all tests should include
+   two files: input and expected output.
+4. Check that running the formatter on the output produces the same output
+   again (the transformation is idempotent).
+
+In order to grow our testsuite, we would borrow test cases from test
+suites of existing libraries like Brittany and Hindent.
+Then we may add test cases for opened issues that Brittany and Hindent have.
+
+When we're confident enough, we can start “mining” new issues by running
+the program on real source code from Hackage till we don't get new issues
+anymore. For every issue that we find this way, a test case should be added.
+
+### Functionality of executable
+
+* In all cases the program should test if the produced AST is the same as
+  the one we originally parsed and if it differs, an error should be
+  displayed suggesting reporting this on our issue tracker.
+* Check mode: return non-zero exit code if any transformations would be
+  applied.
+* Modification in place and printing of formatted code to stdout.
+* A flag for version/commit information.
+* An option to specify location of config file.
+* Options to specify parameters that come from config files on command line
+  instead (currently this is just dynamic options enabled by default, such
+  as langauge extensions).
+
+### Why not contribute to/fork HIndent or Brittany?
+
+We want to simultaneously optimize three goals:
+
+1. simplicity of implementation,
+2. efficiency,
+3. predictable and readable output that doesn't overuse vertical spacing.
+
+Hindent aims for (1) and (2) by still producing something palatable in (3).
+Brittany gives up on
+(1) but goes a long way towards (3) and presumably does OK on (2). Ormolu
+goes for (1), (2) and (3), by outsourcing the hard part of (3) to the user.
+Ormolu is less normative than Brittany, and less normative than Hindent,
+but arguably stills achieves consistent style.
+
+Forking or contributing to Hindent is not an option because if we replace
+`haskell-src-exts` with `ghc` (or `ghc-exact-print`) then we'll have to work
+with a different AST type and all the code in Hindent will become
+incompatible and there won't be much code to be re-used in that case. It is
+also possible that we'll find a nicer way to write pretty-printer.
+
+## Examples
+
+A list of formatting examples can be found [here](data/examples).
+
+[brittany]: https://hackage.haskell.org/package/brittany
+[hindent]: https://hackage.haskell.org/package/hindent
+[hindent-5-blog]: https://chrisdone.com/posts/hindent-5
+[stylish-haskell]: https://hackage.haskell.org/package/stylish-haskell
+[haskell-formatter]: https://hackage.haskell.org/package/haskell-formatter
+[ghc]: https://hackage.haskell.org/package/ghc
+[outputable]: https://hackage.haskell.org/package/ghc-8.4.3/docs/Outputable.html
+[haskell-src-exts]: https://hackage.haskell.org/package/haskell-src-exts
+[ghc-exactprint]: https://hackage.haskell.org/package/ghc-exactprint
+[hindent-printer]: https://github.com/commercialhaskell/hindent/blob/master/src/HIndent/Pretty.hs
+[pretty-doc]: http://hackage.haskell.org/package/pretty-1.1.3.6/docs/Text-PrettyPrint.html#t:Doc
+[wl-pprint-doc]: http://hackage.haskell.org/package/wl-pprint-1.2.1/docs/Text-PrettyPrint-Leijen.html#t:Doc
diff --git a/LICENSE.md b/LICENSE.md
new file mode 100644
--- /dev/null
+++ b/LICENSE.md
@@ -0,0 +1,28 @@
+Copyright © 2018–present Tweag I/O
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice,
+  this list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright
+  notice, this list of conditions and the following disclaimer in the
+  documentation and/or other materials provided with the distribution.
+
+* Neither the name Tweag I/O nor the names of contributors may be used to
+  endorse or promote products derived from this software without specific
+  prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS “AS IS” AND ANY EXPRESS
+OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
+OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
new file mode 100644
--- /dev/null
+++ b/README.md
@@ -0,0 +1,133 @@
+# Ormolu
+
+[![License BSD3](https://img.shields.io/badge/license-BSD3-brightgreen.svg)](http://opensource.org/licenses/BSD-3-Clause)
+[![Hackage](https://img.shields.io/hackage/v/ormolu.svg?style=flat)](https://hackage.haskell.org/package/ormolu)
+[![Stackage Nightly](http://stackage.org/package/ormolu/badge/nightly)](http://stackage.org/nightly/package/ormolu)
+[![Stackage LTS](http://stackage.org/package/ormolu/badge/lts)](http://stackage.org/lts/package/ormolu)
+[![CircleCI](https://circleci.com/gh/tweag/ormolu/tree/master.svg?style=svg&circle-token=cfd37a39265561eb44e608f97cf953cb2a394c03)](https://circleci.com/gh/tweag/ormolu/tree/master)
+
+Ormolu is a formatter for Haskell source code. The project was created with
+the following goals in mind:
+
+* Using GHC's own parser to avoid parsing problems caused by
+  [`haskell-src-exts`][haskell-src-exts].
+* Let some whitespace be programmable. The layout of the input influences
+  the layout choices in the output. This means that the choices between
+  single-line/multi-line layouts in each particular situation are made by
+  the user, not by an algorithm. This makes the implementation simpler and
+  leaves some control to the user while still guaranteeing that the
+  formatted code is stylistically consistent.
+* Writing code in such a way so it's easy to modify and maintain.
+* Implementing one “true” formatting style which admits no configuration.
+* That formatting style aims to result in minimal diffs while still
+  remaining very close to “conventional” Haskell formatting people use.
+* Choose a style compatible with modern dialects of Haskell. As new Haskell
+  extensions enter broad use, we may change the style to accomodate them.
+* Idempotence: formatting already formatted code doesn't change it.
+* Be well-tested and robust to the point that it can be used in large
+  projects without exposing unfortunate, disappointing bugs here and there.
+
+## Building
+
+The easiest way to build the project is with Nix:
+
+```console
+$ nix-build -A ormolu
+```
+
+Or with `cabal-install` from the Nix shell:
+
+```console
+$ nix-shell --run "cabal new-build"
+```
+
+Alternatively, `stack` could be used with a `stack.yaml` file as follows.
+
+```console
+$ cat stack.yaml
+resolver: lts-14.3
+packages:
+- '.'
+
+$ stack build
+```
+
+To use Ormolu directly from GitHub with Nix, this snippet may come in handy:
+
+```nix
+# This overlay adds Ormolu straight from GitHub.
+self: super:
+
+let source = super.fetchFromGitHub {
+      owner = "tweag";
+      repo = "ormolu";
+      rev = "de279d80122b287374d4ed87c7b630db1f157642"; # update as necessary
+      sha256 = "0qrxfk62ww6b60ha9sqcgl4nb2n5fhf66a65wszjngwkybwlzmrv"; # as well
+    };
+    ormolu = import source { pkgs = self; };
+in {
+  haskell = super.haskell // {
+    packages = super.haskell.packages // {
+      "${ormolu.ormoluCompiler}" = super.haskell.packages.${ormolu.ormoluCompiler}.override {
+        overrides = ormolu.ormoluOverlay;
+      };
+    };
+  };
+}
+```
+
+## Usage
+
+The following will print the formatted output to the standard output.
+
+```console
+$ ormolu Module.hs
+```
+
+Add `--mode inplace` to replace the contents of the input file with the
+formatted output.
+
+```console
+$ ormolu --mode inplace Module.hs
+```
+
+## Current limitations
+
+* Does not handle CPP (wontfix, see [the design document][design]).
+* Input modules should be parsable by Haddock, which is a bit stricter
+  criterion than just being valid Haskell modules.
+* Various minor idempotence issues, most of them are related to comments.
+
+## Editor integration
+
+We know of the following editor integrations:
+
+* [For Emacs][emacs-package]
+
+## Running on Hackage
+
+It's possible to try Ormolu on arbitrary packages from Hackage. For that
+execute (from the root of the cloned repo):
+
+```console
+$ nix-build -A hackage.<package>
+```
+
+Then inspect `result/log.txt` for possible problems. The derivation will
+also contain formatted `.hs` files for inspection and original inputs with
+`.hs-original` extension (those are with CPP dropped, exactly what is fed
+into Ormolu).
+
+## Contributing
+
+See [CONTRIBUTING.md](./CONTRIBUTING.md).
+
+## License
+
+See [LICENSE.md](./LICENSE.md).
+
+Copyright © 2018–present Tweag I/O
+
+[design]: ./DESIGN.md#cpp
+[haskell-src-exts]: https://hackage.haskell.org/package/haskell-src-exts
+[emacs-package]: https://github.com/vyorkin/ormolu.el
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,6 @@
+module Main (main) where
+
+import Distribution.Simple
+
+main :: IO ()
+main = defaultMain
diff --git a/app/Main.hs b/app/Main.hs
new file mode 100644
--- /dev/null
+++ b/app/Main.hs
@@ -0,0 +1,168 @@
+{-# LANGUAGE CPP             #-}
+{-# LANGUAGE LambdaCase      #-}
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE TemplateHaskell #-}
+
+module Main (main) where
+
+import Control.Monad
+import Data.List (intercalate, sort)
+import Data.Version (showVersion)
+import Development.GitRev
+import Options.Applicative
+import Ormolu
+import Ormolu.Parser (manualExts)
+import Ormolu.Utils (showOutputable)
+import Paths_ormolu (version)
+import System.Exit (ExitCode (..), exitWith)
+import System.IO (hPutStrLn, stderr)
+import qualified Data.Text.IO as TIO
+
+-- | Entry point of the program.
+
+main :: IO ()
+main = withPrettyOrmoluExceptions $ do
+  Opts {..} <- execParser optsParserInfo
+  let formatOne' = formatOne optMode optConfig
+  case optInputFiles of
+    [] -> formatOne' Nothing
+    ["-"] -> formatOne' Nothing
+    xs -> mapM_ (formatOne' . Just) xs
+
+-- | Format a single input.
+
+formatOne
+  :: Mode                       -- ^ Mode of operation
+  -> Config                     -- ^ Configuration
+  -> Maybe FilePath             -- ^ File to format or stdin as 'Nothing'
+  -> IO ()
+formatOne mode config = \case
+  Nothing -> do
+    r <- ormoluStdin config
+    case mode of
+      Stdout -> TIO.putStr r
+      _ ->  do
+        hPutStrLn stderr
+          "This feature is not supported when input comes from stdin."
+          -- 101 is different from all the other exit codes we already use.
+        exitWith (ExitFailure 101)
+  Just inputFile -> do
+    r <- ormoluFile config inputFile
+    case mode of
+      Stdout ->
+        TIO.putStr r
+      InPlace ->
+        TIO.writeFile inputFile r
+      Check -> do
+        r' <- TIO.readFile inputFile
+        when (r /= r') $
+          -- 100 is different to all the other exit code that are emitted
+          -- either from an 'OrmoluException' or from 'error' and
+          -- 'notImplemented'.
+          exitWith (ExitFailure 100)
+
+----------------------------------------------------------------------------
+-- Command line options parsing.
+
+data Opts = Opts
+  { optMode :: !Mode
+    -- ^ Mode of operation
+  , optConfig :: !Config
+    -- ^ Ormolu 'Config'
+  , optInputFiles :: ![FilePath]
+    -- ^ Haskell source files to format or stdin (when the list is empty)
+  }
+
+-- | Mode of operation.
+
+data Mode
+  = Stdout                      -- ^ Output formatted source code to stdout
+  | InPlace                     -- ^ Overwrite original file
+  | Check                       -- ^ Exit with non-zero status code if
+                                -- source is not already formatted
+  deriving (Eq, Show)
+
+optsParserInfo :: ParserInfo Opts
+optsParserInfo = info (helper <*> ver <*> exts <*> optsParser) . mconcat $
+  [ fullDesc
+  , progDesc ""
+  , header ""
+  ]
+  where
+    ver :: Parser (a -> a)
+    ver = infoOption verStr . mconcat $
+      [ long "version"
+      , short 'v'
+      , help "Print version of the program"
+      ]
+    verStr = intercalate "\n"
+      [ unwords
+        [ "ormolu"
+        , showVersion version
+        , $gitBranch
+        , $gitHash
+        ]
+      , "using ghc " ++ VERSION_ghc
+      ]
+    exts :: Parser (a -> a)
+    exts = infoOption displayExts . mconcat $
+      [ long "manual-exts"
+      , help "Display extensions that need to be enabled manually"
+      ]
+    displayExts = unlines $ sort (showOutputable <$> manualExts)
+
+optsParser :: Parser Opts
+optsParser = Opts
+  <$> (option parseMode . mconcat)
+    [ long "mode"
+    , short 'm'
+    , metavar "MODE"
+    , value Stdout
+    , help "Mode of operation: 'stdout' (default), 'inplace', or 'check'"
+    ]
+  <*> configParser
+  <*> (many . strArgument . mconcat)
+    [ metavar "FILE"
+    , help "Haskell source files to format or stdin (default)"
+    ]
+
+configParser :: Parser Config
+configParser = Config
+  <$> (fmap (fmap DynOption) . many . strOption . mconcat)
+    [ long "ghc-opt"
+    , short 'o'
+    , metavar "OPT"
+    , help "GHC options to enable (e.g. language extensions)"
+    ]
+  <*> (switch . mconcat)
+    [ long "unsafe"
+    , short 'u'
+    , help "Do formatting faster but without automatic detection of defects"
+    ]
+  <*> (switch . mconcat)
+    [ long "debug"
+    , short 'd'
+    , help "Output information useful for debugging"
+    ]
+  <*> (switch . mconcat)
+    [ long "tolerate-cpp"
+    , short 'p'
+    , help "Do not fail if CPP pragma is present"
+    ]
+  <*> (switch . mconcat)
+    [ long "check-idempotency"
+    , short 'c'
+    , help "Fail if formatting is not idempotent"
+    ]
+
+----------------------------------------------------------------------------
+-- Helpers
+
+-- | Parse 'Mode'.
+
+parseMode :: ReadM Mode
+parseMode = eitherReader $ \case
+  "stdout" -> Right Stdout
+  "inplace" -> Right InPlace
+  "check" -> Right Check
+  s -> Left $ "unknown mode: " ++ s
diff --git a/data/examples/declaration/annotation/annotation-out.hs b/data/examples/declaration/annotation/annotation-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/annotation/annotation-out.hs
@@ -0,0 +1,21 @@
+{-# ANN module (5 :: Int) #-}
+
+{-# ANN
+  module
+  ( 5 ::
+      Int
+  )
+  #-}
+
+{-# ANN foo "hey" #-}
+foo :: Int
+foo = 5
+
+{-# ANN
+  Char
+  (Just 42)
+  #-}
+
+data Foo = Foo Int
+{-# ANN type Foo ("HLint: ignore") #-}
+{- Comment -}
diff --git a/data/examples/declaration/annotation/annotation.hs b/data/examples/declaration/annotation/annotation.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/annotation/annotation.hs
@@ -0,0 +1,20 @@
+{-#ANN          module        (5 :: Int)#-}
+
+{-#       ANN module        (5
+   :: Int)#-}
+
+{-#       ANN      foo        "hey" #-}
+
+foo :: Int
+foo = 5
+
+{-#       ANN
+    Char
+
+    (Just 42)#-}
+
+data Foo = Foo Int
+
+{-# ANN type Foo ("HLint: ignore") #-}
+
+{- Comment -}
diff --git a/data/examples/declaration/class/associated-data1-out.hs b/data/examples/declaration/class/associated-data1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/associated-data1-out.hs
@@ -0,0 +1,14 @@
+{-# LANGUAGE TypeFamilies #-}
+
+class Foo a where data FooBar a
+
+-- | Something.
+class Bar a where
+
+  -- | Bar bar
+  data BarBar a
+
+  -- | Bar baz
+  data
+    BarBaz
+      a
diff --git a/data/examples/declaration/class/associated-data1.hs b/data/examples/declaration/class/associated-data1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/associated-data1.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE TypeFamilies #-}
+
+class Foo a where data FooBar a
+
+-- | Something.
+class Bar a
+  where
+    -- | Bar bar
+    data BarBar a
+    -- | Bar baz
+    data family BarBaz
+        a
diff --git a/data/examples/declaration/class/associated-data2-out.hs b/data/examples/declaration/class/associated-data2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/associated-data2-out.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE TypeFamilies #-}
+
+module Main where
+
+-- | Something more.
+class Baz a where
+
+  -- | Baz bar
+  data
+    BazBar
+      a
+      b
+      c
+
+  -- | Baz baz
+  data
+    BazBaz
+      b
+      a
+      c
diff --git a/data/examples/declaration/class/associated-data2.hs b/data/examples/declaration/class/associated-data2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/associated-data2.hs
@@ -0,0 +1,17 @@
+module Main where
+
+{-# LANGUAGE TypeFamilies #-}
+
+-- | Something more.
+class Baz a where
+    -- | Baz bar
+    data BazBar
+        a
+        b
+        c
+
+    -- | Baz baz
+    data family BazBaz
+        b
+        a
+        c
diff --git a/data/examples/declaration/class/associated-type-defaults-out.hs b/data/examples/declaration/class/associated-type-defaults-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/associated-type-defaults-out.hs
@@ -0,0 +1,28 @@
+{-# LANGUAGE TypeFamilies #-}
+
+class Foo a where type FooBar a = Int
+
+-- | Something.
+class Bar a where
+
+  -- Define bar
+  type
+    BarBar a =
+      BarBaz a
+
+  -- Define baz
+  type
+    BarBaz
+      a =
+      BarBar -- Middle comment
+        a
+
+class Baz a where
+
+  type
+    BazBar
+      a
+
+  type
+    BazBar a =
+      Bar a
diff --git a/data/examples/declaration/class/associated-type-defaults.hs b/data/examples/declaration/class/associated-type-defaults.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/associated-type-defaults.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE TypeFamilies #-}
+
+class Foo a where type FooBar a = Int
+
+-- | Something.
+class Bar a where
+  -- Define bar
+  type BarBar a
+    = BarBaz a
+  -- Define baz
+  type BarBaz
+         a = BarBar -- Middle comment
+          a
+
+class Baz a where
+  type BazBar
+         a
+
+  type BazBar a =
+         Bar a
diff --git a/data/examples/declaration/class/associated-types1-out.hs b/data/examples/declaration/class/associated-types1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/associated-types1-out.hs
@@ -0,0 +1,14 @@
+{-# LANGUAGE TypeFamilies #-}
+
+class Foo a where type FooBar a
+
+-- | Something.
+class Bar a where
+
+  -- | Bar bar
+  type BarBar a
+
+  -- | Bar baz
+  type
+    BarBaz
+      a
diff --git a/data/examples/declaration/class/associated-types1.hs b/data/examples/declaration/class/associated-types1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/associated-types1.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE TypeFamilies #-}
+
+class Foo a where type FooBar a
+
+-- | Something.
+class Bar a
+  where
+    -- | Bar bar
+    type BarBar a
+    -- | Bar baz
+    type BarBaz
+        a
diff --git a/data/examples/declaration/class/associated-types2-out.hs b/data/examples/declaration/class/associated-types2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/associated-types2-out.hs
@@ -0,0 +1,21 @@
+{-# LANGUAGE TypeFamilies #-}
+
+module Main where
+
+-- | Something more.
+class Baz a where
+
+  -- | Baz bar
+  type
+    BazBar
+      a -- Foo
+      b -- Bar
+      c
+
+  -- | Baz baz
+  type
+    -- After type
+    BazBaz
+      b
+      a
+      c
diff --git a/data/examples/declaration/class/associated-types2.hs b/data/examples/declaration/class/associated-types2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/associated-types2.hs
@@ -0,0 +1,18 @@
+module Main where
+
+{-# LANGUAGE TypeFamilies #-}
+
+-- | Something more.
+class Baz a where
+    -- | Baz bar
+    type BazBar
+        a      -- Foo
+        b      -- Bar
+        c
+
+    -- | Baz baz
+    type -- After type
+         BazBaz
+        b
+        a
+        c
diff --git a/data/examples/declaration/class/default-implementations-comments-out.hs b/data/examples/declaration/class/default-implementations-comments-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/default-implementations-comments-out.hs
@@ -0,0 +1,27 @@
+module Main where
+
+-- | Baz
+class Baz a where
+
+  foobar :: a -> a
+  foobar a =
+    barbaz (bazbar a)
+
+  -- | Bar baz
+  barbaz ::
+    a -> a
+
+  -- | Baz bar
+  bazbar ::
+    a ->
+    a
+
+  -- First comment
+  barbaz a =
+    bazbar -- Middle comment
+      a
+
+  -- Last comment
+  bazbar a =
+    barbaz
+      a
diff --git a/data/examples/declaration/class/default-implementations-comments.hs b/data/examples/declaration/class/default-implementations-comments.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/default-implementations-comments.hs
@@ -0,0 +1,22 @@
+module Main where
+
+-- | Baz
+class Baz a where
+    foobar :: a -> a
+    foobar a =
+        barbaz (bazbar a)
+    -- | Bar baz
+    barbaz ::
+        a -> a
+    -- | Baz bar
+    bazbar ::
+        a ->
+        a
+    -- First comment
+    barbaz a
+        = bazbar -- Middle comment
+            a
+    -- Last comment
+    bazbar a
+        = barbaz
+            a
diff --git a/data/examples/declaration/class/default-implementations-out.hs b/data/examples/declaration/class/default-implementations-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/default-implementations-out.hs
@@ -0,0 +1,13 @@
+module Main where
+
+-- | Foo
+class Foo a where
+  foo :: a -> a
+  foo a = a
+
+-- | Bar
+class Bar a where
+  bar ::
+    a ->
+    Int
+  bar = const 0
diff --git a/data/examples/declaration/class/default-implementations.hs b/data/examples/declaration/class/default-implementations.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/default-implementations.hs
@@ -0,0 +1,13 @@
+module Main where
+
+-- | Foo
+class Foo a where
+    foo :: a -> a
+    foo a = a
+
+-- | Bar
+class Bar a where
+    bar ::
+           a
+        -> Int
+    bar = const 0
diff --git a/data/examples/declaration/class/default-signatures-out.hs b/data/examples/declaration/class/default-signatures-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/default-signatures-out.hs
@@ -0,0 +1,26 @@
+{-# LANGUAGE DefaultSignatures #-}
+
+module Main where
+
+-- | Something else.
+class Bar a where
+
+  -- | Bar
+  bar ::
+    String ->
+    String ->
+    a
+
+  -- Pointless comment
+  default bar ::
+    ( Read a,
+      Semigroup a
+    ) =>
+    a ->
+    a ->
+    a
+  -- Even more pointless comment
+  bar
+    a
+    b =
+      read a <> read b
diff --git a/data/examples/declaration/class/default-signatures-simple-out.hs b/data/examples/declaration/class/default-signatures-simple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/default-signatures-simple-out.hs
@@ -0,0 +1,10 @@
+module Main where
+
+-- | Something.
+class Foo a where
+
+  -- | Foo
+  foo :: a -> String
+
+  default foo :: Show a => a -> String
+  foo = show
diff --git a/data/examples/declaration/class/default-signatures-simple.hs b/data/examples/declaration/class/default-signatures-simple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/default-signatures-simple.hs
@@ -0,0 +1,8 @@
+module Main where
+
+-- | Something.
+class Foo a where
+    -- | Foo
+    foo :: a -> String
+    default foo :: Show a => a -> String
+    foo = show
diff --git a/data/examples/declaration/class/default-signatures.hs b/data/examples/declaration/class/default-signatures.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/default-signatures.hs
@@ -0,0 +1,26 @@
+module Main where
+
+{-# LANGUAGE DefaultSignatures #-}
+
+-- | Something else.
+class Bar a
+  where
+    -- | Bar
+    bar ::
+           String
+        -> String
+        -> a
+
+    -- Pointless comment
+    default bar :: (
+        Read a,
+        Semigroup a
+      ) =>
+      a -> a -> a
+
+    -- Even more pointless comment
+    bar
+      a
+      b
+      =
+      read a <> read b
diff --git a/data/examples/declaration/class/dependency-super-classes-out.hs b/data/examples/declaration/class/dependency-super-classes-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/dependency-super-classes-out.hs
@@ -0,0 +1,27 @@
+{-# LANGUAGE FunctionalDependencies #-}
+
+module Main where
+
+-- | Something.
+class (MonadReader r s, MonadWriter w m) => MonadState s m | m -> s where
+
+  get :: m s
+
+  put :: s -> m ()
+
+-- | 'MonadParsec'
+class
+  ( Stream s, -- Token streams
+    MonadPlus m -- Potential for failure
+  ) =>
+  MonadParsec e s m
+    | m -> e s where
+
+  -- | 'getState' returns state
+  getState ::
+    m s
+
+  -- | 'putState' sets state
+  putState ::
+    s ->
+    m ()
diff --git a/data/examples/declaration/class/dependency-super-classes.hs b/data/examples/declaration/class/dependency-super-classes.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/dependency-super-classes.hs
@@ -0,0 +1,24 @@
+module Main where
+
+{-# LANGUAGE FunctionalDependencies #-}
+
+-- | Something.
+class ( MonadReader r s,MonadWriter w m ) => MonadState s m| m -> s where
+    get :: m s
+    put :: s -> m ()
+
+-- | 'MonadParsec'
+
+class (
+        Stream s, -- Token streams
+        MonadPlus m -- Potential for failure
+    ) => MonadParsec e s m | m -> e s
+  where
+    -- | 'getState' returns state
+    getState
+        ::
+            m s
+    -- | 'putState' sets state
+    putState ::
+            s
+         -> m ()
diff --git a/data/examples/declaration/class/empty-classes-out.hs b/data/examples/declaration/class/empty-classes-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/empty-classes-out.hs
@@ -0,0 +1,7 @@
+module Main where
+
+-- | Foo!
+class Foo a
+
+-- | Bar!
+class Bar a
diff --git a/data/examples/declaration/class/empty-classes.hs b/data/examples/declaration/class/empty-classes.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/empty-classes.hs
@@ -0,0 +1,6 @@
+module Main where
+
+-- | Foo!
+class Foo a where
+-- | Bar!
+class Bar a
diff --git a/data/examples/declaration/class/functional-dependencies-out.hs b/data/examples/declaration/class/functional-dependencies-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/functional-dependencies-out.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE FunctionalDependencies #-}
+
+module Main where
+
+-- | Something.
+class Foo a b | a -> b
+
+class Bar a b | a -> b, b -> a where bar :: a
+
+-- | Something else.
+class
+  Baz a b c d
+    | a b -> c d, -- Foo
+      b c -> a d, -- Bar
+      a c -> b d, -- Baz
+      a c d -> b,
+      a b d -> a b c d where
+  baz :: a -> b
diff --git a/data/examples/declaration/class/functional-dependencies.hs b/data/examples/declaration/class/functional-dependencies.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/functional-dependencies.hs
@@ -0,0 +1,18 @@
+module Main where
+
+{-# LANGUAGE FunctionalDependencies #-}
+
+-- | Something.
+class Foo a b | a -> b
+
+class Bar a b | a -> b, b -> a where bar :: a
+
+-- | Something else.
+class Baz a b c d
+    | a b -> c d -- Foo
+    , b c -> a d  -- Bar
+    , a c -> b d-- Baz
+    , a c d -> b
+    , a b d -> a b c d
+  where
+    baz :: a -> b
diff --git a/data/examples/declaration/class/multi-parameters1-out.hs b/data/examples/declaration/class/multi-parameters1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/multi-parameters1-out.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE MultiParamTypeClasses #-}
+
+class Foo a b where foo :: a -> b
+
+-- | Something.
+class Bar a b c d where
+  bar ::
+    a ->
+    b ->
+    c ->
+    d
+
+class -- Before name
+  Baz where
+  baz :: Int
diff --git a/data/examples/declaration/class/multi-parameters1.hs b/data/examples/declaration/class/multi-parameters1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/multi-parameters1.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE MultiParamTypeClasses #-}
+
+class Foo a b where foo :: a -> b
+
+-- | Something.
+class Bar a b c d
+  where
+    bar ::
+           a
+        -> b
+        -> c
+        -> d
+
+class -- Before name
+    Baz
+  where
+    baz :: Int
+
diff --git a/data/examples/declaration/class/multi-parameters2-out.hs b/data/examples/declaration/class/multi-parameters2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/multi-parameters2-out.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE MultiParamTypeClasses #-}
+
+module Main where
+
+-- | Something else.
+class
+  BarBaz
+    a -- Foo
+    b -- Bar
+    c -- Baz bar
+    d -- Baz baz
+    e -- Rest
+    f where
+
+  barbaz ::
+    a -> f
+
+  bazbar ::
+    e ->
+    f
diff --git a/data/examples/declaration/class/multi-parameters2.hs b/data/examples/declaration/class/multi-parameters2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/multi-parameters2.hs
@@ -0,0 +1,18 @@
+module Main where
+
+{-# LANGUAGE MultiParamTypeClasses #-}
+
+-- | Something else.
+class
+      BarBaz
+        a              -- Foo
+        b              -- Bar
+        c              -- Baz bar
+        d              -- Baz baz
+        e              -- Rest
+        f where
+    barbaz ::
+        a -> f
+    bazbar ::
+        e ->
+        f
diff --git a/data/examples/declaration/class/poly-kinded-classes-out.hs b/data/examples/declaration/class/poly-kinded-classes-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/poly-kinded-classes-out.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE PolyKinds #-}
+
+class Foo (a :: k)
+
+class
+  Bar
+    ( a :: -- Variable
+        * -- Star
+    )
diff --git a/data/examples/declaration/class/poly-kinded-classes.hs b/data/examples/declaration/class/poly-kinded-classes.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/poly-kinded-classes.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE PolyKinds #-}
+
+class Foo (a::k)
+
+class Bar
+    (a -- Variable
+       :: * -- Star
+    )
diff --git a/data/examples/declaration/class/single-parameters-out.hs b/data/examples/declaration/class/single-parameters-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/single-parameters-out.hs
@@ -0,0 +1,28 @@
+module Main where
+
+-- | Something.
+class Foo a where foo :: a
+
+-- | Something more.
+class Bar a where
+  -- | Bar
+  bar :: a -> a -> a
+
+class Baz a where
+  -- | Baz
+  baz ::
+    -- | First argument
+    ( a,
+      a
+    ) ->
+    -- | Second argument
+    a ->
+    -- | Return value
+    a
+
+class BarBaz a where
+
+  barbaz ::
+    a -> b
+
+  bazbar :: b -> a
diff --git a/data/examples/declaration/class/single-parameters.hs b/data/examples/declaration/class/single-parameters.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/single-parameters.hs
@@ -0,0 +1,22 @@
+module Main where
+
+-- | Something.
+class Foo a where foo :: a
+
+-- | Something more.
+class Bar a where
+    -- | Bar
+    bar :: a -> a -> a
+
+class Baz a where
+    -- | Baz
+    baz ::
+        (a,
+         a) -- ^ First argument
+        -> a -- ^ Second argument
+        -> a -- ^ Return value
+
+class BarBaz a where
+    barbaz ::
+        a -> b
+    bazbar :: b -> a
diff --git a/data/examples/declaration/class/super-classes-out.hs b/data/examples/declaration/class/super-classes-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/super-classes-out.hs
@@ -0,0 +1,14 @@
+class Foo a
+
+class Foo a => Bar a
+
+class
+  (Foo a, Bar a) =>
+  Baz a
+
+class
+  ( Foo a, -- Foo?
+    Bar a, -- Bar?
+    Baz a -- Baz
+  ) =>
+  BarBar a
diff --git a/data/examples/declaration/class/super-classes.hs b/data/examples/declaration/class/super-classes.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/super-classes.hs
@@ -0,0 +1,9 @@
+class () => Foo a
+class Foo a  => Bar a
+class (Foo a,Bar a) =>
+      Baz a
+class (
+    Foo a, -- Foo?
+    Bar a, -- Bar?
+    Baz a  -- Baz
+  ) => BarBar a
diff --git a/data/examples/declaration/class/type-operators1-out.hs b/data/examples/declaration/class/type-operators1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/type-operators1-out.hs
@@ -0,0 +1,21 @@
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TypeOperators #-}
+
+class (:$) a b
+
+class
+  (:&)
+    a
+    b
+
+class a :* b
+
+class
+  a -- Before operator
+    :+ b -- After operator
+
+class
+  ( f
+      :. g
+  )
+    a
diff --git a/data/examples/declaration/class/type-operators1.hs b/data/examples/declaration/class/type-operators1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/type-operators1.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TypeOperators #-}
+
+class (:$) a b
+
+class (:&)
+    a
+        b
+
+class    a:*b
+
+class
+    a -- Before operator
+    :+
+    b -- After operator
+
+class (
+    f :. g
+  ) a
diff --git a/data/examples/declaration/class/type-operators2-out.hs b/data/examples/declaration/class/type-operators2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/type-operators2-out.hs
@@ -0,0 +1,16 @@
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TypeOperators #-}
+
+class a `Pair` b
+
+class
+  a
+    `Sum` b
+
+class (f `Product` g) a
+
+class
+  ( f
+      `Sum` g
+  )
+    a
diff --git a/data/examples/declaration/class/type-operators2.hs b/data/examples/declaration/class/type-operators2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/class/type-operators2.hs
@@ -0,0 +1,16 @@
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TypeOperators #-}
+
+class
+    a`Pair`b
+
+class
+          a
+    `Sum` b
+
+class (f`Product`g)a
+
+class (
+    f `Sum` g
+  ) a
+
diff --git a/data/examples/declaration/data/deriving-out.hs b/data/examples/declaration/data/deriving-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/deriving-out.hs
@@ -0,0 +1,2 @@
+newtype R r a = R (ReaderT r IO a)
+  deriving (MonadReader r)
diff --git a/data/examples/declaration/data/deriving-strategies-out.hs b/data/examples/declaration/data/deriving-strategies-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/deriving-strategies-out.hs
@@ -0,0 +1,14 @@
+module Main where
+
+-- | Something.
+newtype Foo = Foo Int
+  deriving stock (Eq, Show, Generic)
+  deriving anyclass
+    ( ToJSON,
+      FromJSON
+    )
+  deriving newtype (Num)
+  deriving (Monoid) via (Sum Int)
+  deriving
+    (Semigroup)
+    via (Sum Int)
diff --git a/data/examples/declaration/data/deriving-strategies.hs b/data/examples/declaration/data/deriving-strategies.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/deriving-strategies.hs
@@ -0,0 +1,14 @@
+module Main where
+
+-- | Something.
+
+newtype Foo = Foo Int
+  deriving stock (Eq, Show, Generic)
+  deriving anyclass
+    ( ToJSON
+    , FromJSON
+    )
+  deriving newtype (Num)
+  deriving Monoid via (Sum Int)
+  deriving Semigroup
+    via (Sum Int)
diff --git a/data/examples/declaration/data/deriving.hs b/data/examples/declaration/data/deriving.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/deriving.hs
@@ -0,0 +1,2 @@
+newtype R r a = R (ReaderT r IO a)
+  deriving (MonadReader r)
diff --git a/data/examples/declaration/data/empty-out.hs b/data/examples/declaration/data/empty-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/empty-out.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE EmptyDataDecls #-}
+
+data Foo
diff --git a/data/examples/declaration/data/empty.hs b/data/examples/declaration/data/empty.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/empty.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE EmptyDataDecls #-}
+
+data Foo
diff --git a/data/examples/declaration/data/existential-multiline-out.hs b/data/examples/declaration/data/existential-multiline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/existential-multiline-out.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE ExistentialQuantification #-}
+
+data Foo
+  = forall a. MkFoo a (a -> Bool)
+  | forall a. Eq a => MkBar a
diff --git a/data/examples/declaration/data/existential-multiline.hs b/data/examples/declaration/data/existential-multiline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/existential-multiline.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE ExistentialQuantification #-}
+
+data Foo
+  = forall a. MkFoo a (a -> Bool)
+  | forall a. Eq a => MkBar a
diff --git a/data/examples/declaration/data/existential-out.hs b/data/examples/declaration/data/existential-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/existential-out.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE ExistentialQuantification #-}
+
+data Foo = forall a. MkFoo a (a -> Bool)
diff --git a/data/examples/declaration/data/existential.hs b/data/examples/declaration/data/existential.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/existential.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE ExistentialQuantification #-}
+
+data Foo = forall a. MkFoo a (a -> Bool)
diff --git a/data/examples/declaration/data/fat-multiline-out.hs b/data/examples/declaration/data/fat-multiline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/fat-multiline-out.hs
@@ -0,0 +1,12 @@
+module Main where
+
+-- | Something.
+data Foo
+  = -- | Foo
+    Foo
+      Int
+      Int
+  | -- | Bar
+    Bar
+      Bool
+      Bool
diff --git a/data/examples/declaration/data/fat-multiline.hs b/data/examples/declaration/data/fat-multiline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/fat-multiline.hs
@@ -0,0 +1,11 @@
+module Main where
+
+-- | Something.
+
+data Foo
+  = Foo Int
+        Int
+    -- ^ Foo
+  | Bar Bool
+        Bool
+    -- ^ Bar
diff --git a/data/examples/declaration/data/gadt-syntax-out.hs b/data/examples/declaration/data/gadt-syntax-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt-syntax-out.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE GADTSyntax #-}
+
+data Foo where MKFoo :: a -> (a -> Bool) -> Foo
diff --git a/data/examples/declaration/data/gadt-syntax.hs b/data/examples/declaration/data/gadt-syntax.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt-syntax.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE GADTSyntax #-}
+
+data Foo where { MKFoo :: a -> (a->Bool) -> Foo }
diff --git a/data/examples/declaration/data/gadt/multiline-out.hs b/data/examples/declaration/data/gadt/multiline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/multiline-out.hs
@@ -0,0 +1,25 @@
+{-# LANGUAGE ExplicitForAll #-}
+
+module Main where
+
+-- | Here goes a comment.
+data Foo a where
+  -- | 'Foo' is wonderful.
+  Foo ::
+    forall a b.
+    (Show a, Eq b) => -- foo
+      -- bar
+    a ->
+    b ->
+    Foo 'Int
+  -- | But 'Bar' is also not too bad.
+  Bar ::
+    Int ->
+    Maybe Text ->
+    Foo 'Bool
+  -- | So is 'Baz'.
+  Baz ::
+    forall a.
+    a ->
+    Foo 'String
+  (:~>) :: Foo a -> Foo a -> Foo a
diff --git a/data/examples/declaration/data/gadt/multiline.hs b/data/examples/declaration/data/gadt/multiline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/multiline.hs
@@ -0,0 +1,18 @@
+module Main where
+
+{-# LANGUAGE ExplicitForAll #-}
+
+-- | Here goes a comment.
+
+data Foo a where
+  -- | 'Foo' is wonderful.
+  Foo :: forall a b. (Show a, Eq b) -- foo
+    -- bar
+    => a -> b -> Foo 'Int
+  -- | But 'Bar' is also not too bad.
+  Bar
+    :: Int -> Maybe Text -> Foo 'Bool
+  -- | So is 'Baz'.
+  Baz
+    :: forall a. a -> Foo 'String
+  (:~>) :: Foo a -> Foo a -> Foo a
diff --git a/data/examples/declaration/data/gadt/multiple-declaration-out.hs b/data/examples/declaration/data/gadt/multiple-declaration-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/multiple-declaration-out.hs
@@ -0,0 +1,15 @@
+data GADT0 a where
+  GADT01, GADT02 :: Int -> GADT0 a
+
+data GADT1 a where
+  GADT11,
+    GADT12 ::
+    Int ->
+    GADT1 a
+
+data GADT2 a where
+  GADT21,
+    GADT21,
+    GADT22 ::
+    Int ->
+    GADT2 a
diff --git a/data/examples/declaration/data/gadt/multiple-declaration.hs b/data/examples/declaration/data/gadt/multiple-declaration.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/multiple-declaration.hs
@@ -0,0 +1,11 @@
+data GADT0 a where
+  GADT01, GADT02 :: Int -> GADT0 a
+
+data GADT1 a where
+  GADT11
+    , GADT12 :: Int -> GADT1 a
+
+data GADT2 a where
+  GADT21
+    , GADT21
+    , GADT22 :: Int -> GADT2 a
diff --git a/data/examples/declaration/data/gadt/record-out.hs b/data/examples/declaration/data/gadt/record-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/record-out.hs
@@ -0,0 +1,14 @@
+module Main where
+
+-- | Something.
+data Foo where
+  Foo :: {fooX :: Int} -> Foo
+  Bar ::
+    { fooY :: Int,
+      fooBar, fooBaz :: Bool,
+      fooFoo,
+      barBar,
+      bazBaz ::
+        Int
+    } ->
+    Foo
diff --git a/data/examples/declaration/data/gadt/record.hs b/data/examples/declaration/data/gadt/record.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/record.hs
@@ -0,0 +1,12 @@
+module Main where
+
+-- | Something.
+
+data Foo where
+  Foo :: { fooX :: Int } -> Foo
+  Bar :: { fooY :: Int
+         , fooBar, fooBaz :: Bool
+         , fooFoo
+             , barBar
+             , bazBaz :: Int
+         } -> Foo
diff --git a/data/examples/declaration/data/gadt/simple-out.hs b/data/examples/declaration/data/gadt/simple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/simple-out.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE ExplicitForAll #-}
+
+module Main where
+
+-- | Here goes a comment.
+data Foo a where
+  -- | 'Foo' is wonderful.
+  Foo :: forall a b. (Show a, Eq b) => a -> b -> Foo 'Int
+  Bar ::
+    Int ->
+    Text ->
+    -- | But 'Bar' is also not too bad.
+    Foo 'Bool
+  Baz ::
+    forall a.
+    a ->
+    -- | So is 'Baz'.
+    Foo 'String
diff --git a/data/examples/declaration/data/gadt/simple.hs b/data/examples/declaration/data/gadt/simple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/simple.hs
@@ -0,0 +1,11 @@
+module Main where
+
+{-# LANGUAGE ExplicitForAll #-}
+
+-- | Here goes a comment.
+
+data Foo a where
+  -- | 'Foo' is wonderful.
+  Foo :: forall a b. (Show a, Eq b) => a -> b -> Foo 'Int
+  Bar :: Int -> Text -> Foo 'Bool -- ^ But 'Bar' is also not too bad.
+  Baz :: forall a. a -> Foo 'String -- ^ So is 'Baz'.
diff --git a/data/examples/declaration/data/gadt/strictness-out.hs b/data/examples/declaration/data/gadt/strictness-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/strictness-out.hs
@@ -0,0 +1,2 @@
+data Foo a where
+  Foo :: !Int -> {-# UNPACK #-} !Bool -> Foo Int
diff --git a/data/examples/declaration/data/gadt/strictness.hs b/data/examples/declaration/data/gadt/strictness.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/strictness.hs
@@ -0,0 +1,2 @@
+data Foo a where
+  Foo :: !Int -> {-# UNPACK #-} !Bool -> Foo Int
diff --git a/data/examples/declaration/data/infix-out.hs b/data/examples/declaration/data/infix-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/infix-out.hs
@@ -0,0 +1,1 @@
+data Foo a b = a `Foo` b
diff --git a/data/examples/declaration/data/infix.hs b/data/examples/declaration/data/infix.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/infix.hs
@@ -0,0 +1,1 @@
+data Foo a b = a `Foo` b
diff --git a/data/examples/declaration/data/kind-annotations-out.hs b/data/examples/declaration/data/kind-annotations-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/kind-annotations-out.hs
@@ -0,0 +1,3 @@
+data Something (n :: Nat) = Something
+
+data Format (k :: *) (k' :: *) (k'' :: *)
diff --git a/data/examples/declaration/data/kind-annotations.hs b/data/examples/declaration/data/kind-annotations.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/kind-annotations.hs
@@ -0,0 +1,3 @@
+data Something (n :: Nat) = Something
+
+data Format (k :: *) (k' :: *) (k'' :: *)
diff --git a/data/examples/declaration/data/multiline-arg-parens-out.hs b/data/examples/declaration/data/multiline-arg-parens-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/multiline-arg-parens-out.hs
@@ -0,0 +1,10 @@
+module Main where
+
+-- | Something.
+data Foo
+  = Foo
+      Bar
+      (Set Baz) -- and here we go
+        -- and that's it
+      Text
+  deriving (Eq)
diff --git a/data/examples/declaration/data/multiline-arg-parens.hs b/data/examples/declaration/data/multiline-arg-parens.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/multiline-arg-parens.hs
@@ -0,0 +1,10 @@
+module Main where
+
+-- | Something.
+
+data Foo
+  = Foo Bar
+        (Set Baz) -- and here we go
+                  -- and that's it
+        Text
+  deriving (Eq)
diff --git a/data/examples/declaration/data/multiline-names-out.hs b/data/examples/declaration/data/multiline-names-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/multiline-names-out.hs
@@ -0,0 +1,29 @@
+data
+  Foo
+    a
+    b
+  = Foo a b
+
+data a :-> b = Arrow (a -> b)
+
+data (f :* g) a = f a :* g a
+
+data
+  ( f
+      :+ g
+  )
+    a
+  = L (f a)
+  | R (g a)
+
+data a `Arrow` b = Arrow' (a -> b)
+
+data (f `Product` g) a = f a `Product` g a
+
+data
+  ( f
+      `Sum` g
+  )
+    a
+  = L' (f a)
+  | R' (g a)
diff --git a/data/examples/declaration/data/multiline-names.hs b/data/examples/declaration/data/multiline-names.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/multiline-names.hs
@@ -0,0 +1,23 @@
+data Foo a
+         b
+  = Foo a b
+
+data a :-> b = Arrow (a -> b)
+
+data (f :* g) a = f a :* g a
+
+data (f
+      :+
+      g)
+  a = L (f a)
+    | R (g a)
+
+data a `Arrow` b = Arrow' (a -> b)
+
+data (f `Product` g) a = f a `Product` g a
+
+data (f
+      `Sum`
+      g)
+  a = L' (f a)
+    | R' (g a)
diff --git a/data/examples/declaration/data/multiline-out.hs b/data/examples/declaration/data/multiline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/multiline-out.hs
@@ -0,0 +1,12 @@
+module Main where
+
+-- | Here we have 'Foo'.
+data Foo
+  = -- | One
+    Foo
+  | -- | Two
+    Bar Int
+  | -- | Three
+    Baz
+  deriving
+    (Eq, Show)
diff --git a/data/examples/declaration/data/multiline.hs b/data/examples/declaration/data/multiline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/multiline.hs
@@ -0,0 +1,10 @@
+module Main where
+
+-- | Here we have 'Foo'.
+
+data Foo
+  = Foo -- ^ One
+  | Bar Int -- ^ Two
+  | Baz -- ^ Three
+  deriving
+    (Eq, Show)
diff --git a/data/examples/declaration/data/newtype-out.hs b/data/examples/declaration/data/newtype-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/newtype-out.hs
@@ -0,0 +1,5 @@
+module Main where
+
+-- | Something.
+newtype Foo = Foo Int
+  deriving (Eq, Show)
diff --git a/data/examples/declaration/data/newtype.hs b/data/examples/declaration/data/newtype.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/newtype.hs
@@ -0,0 +1,6 @@
+module Main where
+
+-- | Something.
+
+newtype Foo = Foo Int
+  deriving (Eq, Show)
diff --git a/data/examples/declaration/data/record-out.hs b/data/examples/declaration/data/record-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/record-out.hs
@@ -0,0 +1,24 @@
+module Main where
+
+-- | Something.
+data Foo
+  = Foo
+      { -- | X
+        fooX :: Int,
+        -- | Y
+        fooY :: Int,
+        -- | BarBaz
+        fooBar, fooBaz :: NonEmpty (Identity Bool),
+        -- | GagGog
+        fooGag,
+        fooGog ::
+          NonEmpty
+            ( Indentity
+                Bool
+            ),
+        -- | Huh!
+        fooFoo,
+        barBar ::
+          Int
+      }
+  deriving (Eq, Show)
diff --git a/data/examples/declaration/data/record-singleline-out.hs b/data/examples/declaration/data/record-singleline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/record-singleline-out.hs
@@ -0,0 +1,5 @@
+module Main where
+
+-- | Something.
+data Foo = Foo {fooX :: Int, fooY :: Int}
+  deriving (Eq, Show)
diff --git a/data/examples/declaration/data/record-singleline.hs b/data/examples/declaration/data/record-singleline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/record-singleline.hs
@@ -0,0 +1,6 @@
+module Main where
+
+-- | Something.
+
+data Foo = Foo { fooX :: Int , fooY :: Int }
+  deriving (Eq, Show)
diff --git a/data/examples/declaration/data/record.hs b/data/examples/declaration/data/record.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/record.hs
@@ -0,0 +1,14 @@
+module Main where
+
+-- | Something.
+
+data Foo = Foo
+  { fooX :: Int -- ^ X
+  , fooY :: Int -- ^ Y
+  , fooBar, fooBaz :: NonEmpty (Identity Bool) -- ^ BarBaz
+  , fooGag, fooGog :: NonEmpty (Indentity
+                                  Bool)
+    -- ^ GagGog
+  , fooFoo
+      , barBar :: Int -- ^ Huh!
+  } deriving (Eq, Show)
diff --git a/data/examples/declaration/data/simple-broken-out.hs b/data/examples/declaration/data/simple-broken-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/simple-broken-out.hs
@@ -0,0 +1,10 @@
+module Main where
+
+-- | Here we go.
+data Foo
+  = Foo {unFoo :: Int}
+  deriving (Eq)
+
+-- | And once again.
+data Bar = Bar {unBar :: Int}
+  deriving (Eq)
diff --git a/data/examples/declaration/data/simple-broken.hs b/data/examples/declaration/data/simple-broken.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/simple-broken.hs
@@ -0,0 +1,12 @@
+module Main where
+
+-- | Here we go.
+
+data Foo
+  = Foo { unFoo :: Int }
+  deriving (Eq)
+
+-- | And once again.
+
+data Bar = Bar { unBar :: Int }
+  deriving (Eq)
diff --git a/data/examples/declaration/data/simple-out.hs b/data/examples/declaration/data/simple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/simple-out.hs
@@ -0,0 +1,5 @@
+module Main where
+
+-- | And here we have 'Foo'.
+data Foo = Foo | Bar Int | Baz
+  deriving (Eq, Show)
diff --git a/data/examples/declaration/data/simple.hs b/data/examples/declaration/data/simple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/simple.hs
@@ -0,0 +1,6 @@
+module Main where
+
+-- | And here we have 'Foo'.
+
+data Foo = Foo | Bar Int | Baz
+  deriving (Eq, Show)
diff --git a/data/examples/declaration/data/strictness-out.hs b/data/examples/declaration/data/strictness-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/strictness-out.hs
@@ -0,0 +1,4 @@
+module Main where
+
+-- | Something.
+data Foo = Foo !Int {-# UNPACK #-} !Bool {-# NOUNPACK #-} !String
diff --git a/data/examples/declaration/data/strictness.hs b/data/examples/declaration/data/strictness.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/strictness.hs
@@ -0,0 +1,5 @@
+module Main where
+
+-- | Something.
+
+data Foo = Foo !Int {-# UNPACK #-} !Bool {-# NOUNPACK #-} !String
diff --git a/data/examples/declaration/default/default-out.hs b/data/examples/declaration/default/default-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/default/default-out.hs
@@ -0,0 +1,7 @@
+default (Int, Foo, Bar)
+
+default
+  ( Int,
+    Foo,
+    Bar
+  )
diff --git a/data/examples/declaration/default/default.hs b/data/examples/declaration/default/default.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/default/default.hs
@@ -0,0 +1,6 @@
+default        (  Int , Foo     , Bar      )
+
+default ( Int
+               , Foo,
+  Bar
+           )
diff --git a/data/examples/declaration/deriving/multiline-out.hs b/data/examples/declaration/deriving/multiline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/deriving/multiline-out.hs
@@ -0,0 +1,24 @@
+deriving instance
+  Eq
+    Foo
+
+deriving stock instance
+  Show
+    Foo
+
+deriving anyclass instance
+  ToJSON
+    Foo
+
+deriving newtype instance
+  Data
+    Foo
+
+deriving via
+  Foo
+    Int
+  instance
+    Triple
+      A
+      B
+      C
diff --git a/data/examples/declaration/deriving/multiline.hs b/data/examples/declaration/deriving/multiline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/deriving/multiline.hs
@@ -0,0 +1,19 @@
+deriving instance Eq
+                    Foo
+
+deriving stock instance
+  Show
+    Foo
+deriving anyclass instance
+  ToJSON
+    Foo
+deriving newtype instance
+  Data
+    Foo
+
+deriving via Foo
+               Int
+  instance Triple
+             A
+             B
+             C
diff --git a/data/examples/declaration/deriving/overlapping-out.hs b/data/examples/declaration/deriving/overlapping-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/deriving/overlapping-out.hs
@@ -0,0 +1,19 @@
+deriving instance
+  {-# OVERLAPPABLE #-}
+  Ord
+    Foo
+
+deriving instance
+  {-# OVERLAPPING #-}
+  Num
+    Foo
+
+deriving instance
+  {-# OVERLAPS #-}
+  Read
+    Foo
+
+deriving instance
+  {-# INCOHERENT #-}
+  Show
+    Foo
diff --git a/data/examples/declaration/deriving/overlapping.hs b/data/examples/declaration/deriving/overlapping.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/deriving/overlapping.hs
@@ -0,0 +1,17 @@
+deriving instance
+  {-# OVERLAPPABLE #-}
+    Ord
+      Foo
+deriving instance
+  {-# OVERLAPPING #-}
+    Num
+      Foo
+deriving instance
+  {-# OVERLAPS #-}
+    Read
+      Foo
+deriving instance
+  {-# INCOHERENT #-}
+    Show
+      Foo
+
diff --git a/data/examples/declaration/deriving/singleline-out.hs b/data/examples/declaration/deriving/singleline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/deriving/singleline-out.hs
@@ -0,0 +1,17 @@
+deriving instance Eq Foo
+
+deriving stock instance Show Foo
+
+deriving anyclass instance ToJSON Foo
+
+deriving newtype instance Data Foo
+
+deriving instance {-# OVERLAPPABLE #-} Ord Foo
+
+deriving instance {-# OVERLAPPING #-} Num Foo
+
+deriving instance {-# OVERLAPS #-} Read Foo
+
+deriving instance {-# INCOHERENT #-} Show Foo
+
+deriving via Int instance Triple A B C
diff --git a/data/examples/declaration/deriving/singleline.hs b/data/examples/declaration/deriving/singleline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/deriving/singleline.hs
@@ -0,0 +1,12 @@
+deriving instance Eq Foo
+
+deriving stock instance Show Foo
+deriving anyclass instance ToJSON Foo
+deriving newtype instance Data Foo
+
+deriving instance {-# OVERLAPPABLE #-} Ord Foo
+deriving instance {-# OVERLAPPING #-} Num Foo
+deriving instance {-# OVERLAPS #-} Read Foo
+deriving instance {-# INCOHERENT #-} Show Foo
+
+deriving via Int instance Triple A B C
diff --git a/data/examples/declaration/foreign/foreign-export-out.hs b/data/examples/declaration/foreign/foreign-export-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/foreign/foreign-export-out.hs
@@ -0,0 +1,8 @@
+foreign export ccall foo :: Int -> IO Int
+
+-- | 'foreignTomFun' is a very important thing
+foreign export ccall "tomography"
+  foreignTomFun :: StablePtr Storage {- Storage is bad -} -> TomForegin
+
+foreign export {- We can't use capi here -} ccall "dynamic"
+  export_nullaryMeth :: (IO HRESULT) -> IO (Ptr ())
diff --git a/data/examples/declaration/foreign/foreign-export.hs b/data/examples/declaration/foreign/foreign-export.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/foreign/foreign-export.hs
@@ -0,0 +1,8 @@
+foreign export ccall foo :: Int -> IO Int
+
+-- | 'foreignTomFun' is a very important thing
+foreign export ccall "tomography" foreignTomFun
+  :: StablePtr Storage {- Storage is bad -} -> TomForegin
+
+foreign export {- We can't use capi here -} ccall "dynamic"
+   export_nullaryMeth :: (IO HRESULT) -> IO (Ptr ())
diff --git a/data/examples/declaration/foreign/foreign-import-out.hs b/data/examples/declaration/foreign/foreign-import-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/foreign/foreign-import-out.hs
@@ -0,0 +1,25 @@
+{-# LANGUAGE CApiFFI #-}
+
+foreign import ccall safe foo :: Int -> IO Int
+
+-- | 'bar' is a very important thing
+foreign import stdcall "baz" bar :: String -> Int -> IO String
+
+foreign import stdcall unsafe "boo"
+  -- Here is a comment about my foreign function
+  boo :: Int -> Text -> IO Array
+
+foreign import javascript
+  baz ::
+    String ->
+    Int ->
+    IO Foo
+
+foreign import {- We use capi here -} capi "pi.h value pi" c_pi :: CDouble
+
+foreign import stdcall {- This is a bad place for a comment -} "dynamic"
+  dyn_gluBeginSurface ::
+    -- | This 'FunPtr' is extremely dangerous, beware
+    FunPtr (Ptr GLUnurbs -> IO ()) ->
+    Ptr GLUnurbs ->
+    IO ()
diff --git a/data/examples/declaration/foreign/foreign-import.hs b/data/examples/declaration/foreign/foreign-import.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/foreign/foreign-import.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE CApiFFI #-}
+
+foreign import ccall safe foo :: Int -> IO Int
+
+-- | 'bar' is a very important thing
+foreign import stdcall "baz" bar :: String -> Int -> IO String
+
+foreign import stdcall unsafe "boo"
+  -- Here is a comment about my foreign function
+      boo :: Int -> Text -> IO Array
+
+foreign import javascript baz :: String
+  -> Int -> IO Foo
+
+foreign import {- We use capi here -} capi "pi.h value pi" c_pi :: CDouble
+
+foreign import stdcall {- This is a bad place for a comment -} "dynamic" dyn_gluBeginSurface
+  :: FunPtr (Ptr GLUnurbs -> IO ())
+  -- ^ This 'FunPtr' is extremely dangerous, beware
+  ->         Ptr GLUnurbs -> IO ()
diff --git a/data/examples/declaration/instance/associated-data-out.hs b/data/examples/declaration/instance/associated-data-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/associated-data-out.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE TypeFamilies #-}
+
+instance Foo Int where data Bar Int = IntBar Int Int
+
+instance Foo Double where
+  newtype
+    Bar
+      Double
+    = DoubleBar
+        Double
+        Double
+
+instance Foo [a] where
+
+  data Bar [a]
+    = ListBar [Bar a]
+
+  data Baz [a]
+    = ListBaz
diff --git a/data/examples/declaration/instance/associated-data.hs b/data/examples/declaration/instance/associated-data.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/associated-data.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE TypeFamilies #-}
+
+instance Foo Int where data Bar Int  =  IntBar Int Int
+
+instance Foo Double where
+    newtype
+      Bar
+        Double
+        =
+          DoubleBar
+            Double
+            Double
+
+instance Foo [a]
+  where
+    data Bar [a] =
+            ListBar [Bar a]
+    data Baz [a] =
+            ListBaz
diff --git a/data/examples/declaration/instance/associated-types-out.hs b/data/examples/declaration/instance/associated-types-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/associated-types-out.hs
@@ -0,0 +1,14 @@
+{-# LANGUAGE TypeFamilies #-}
+
+instance Foo Int where type Bar Int = Double
+
+instance Foo Double where
+
+  type
+    Bar
+      Double =
+      [Double]
+
+  type
+    Baz Double =
+      [Double]
diff --git a/data/examples/declaration/instance/associated-types.hs b/data/examples/declaration/instance/associated-types.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/associated-types.hs
@@ -0,0 +1,13 @@
+{-# LANGUAGE TypeFamilies #-}
+
+instance Foo Int where type Bar Int = Double
+
+instance Foo Double
+  where
+    type
+      Bar
+        Double
+        =
+          [Double]
+    type instance Baz  Double
+      = [Double]
diff --git a/data/examples/declaration/instance/contexts-comments-out.hs b/data/examples/declaration/instance/contexts-comments-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/contexts-comments-out.hs
@@ -0,0 +1,17 @@
+instance
+  ( Read a, -- Foo
+    Read b,
+    Read
+      ( c, -- Bar
+        d
+      )
+  ) =>
+  Read
+    ( a, -- Baz
+      b,
+      ( c, -- Quux
+        d
+      )
+    )
+  where
+  readsPrec = undefined
diff --git a/data/examples/declaration/instance/contexts-comments.hs b/data/examples/declaration/instance/contexts-comments.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/contexts-comments.hs
@@ -0,0 +1,18 @@
+instance (
+  Read a, -- Foo
+  Read b
+  , Read (
+    c, -- Bar
+    d
+    )
+  )
+  =>
+  Read (
+    a, -- Baz
+    b
+    ,(
+      c, -- Quux
+      d
+    )
+  ) where
+  readsPrec = undefined
diff --git a/data/examples/declaration/instance/contexts-out.hs b/data/examples/declaration/instance/contexts-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/contexts-out.hs
@@ -0,0 +1,18 @@
+instance Eq a => Eq [a] where (==) _ _ = False
+
+instance
+  ( Ord a,
+    Ord b
+  ) =>
+  Ord (a, b)
+  where
+  compare _ _ = GT
+
+instance
+  (Show a, Show b) =>
+  Show
+    ( a,
+      b
+    )
+  where
+  showsPrec _ _ = showString ""
diff --git a/data/examples/declaration/instance/contexts.hs b/data/examples/declaration/instance/contexts.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/contexts.hs
@@ -0,0 +1,14 @@
+instance Eq a=>Eq [a] where (==) _ _ = False
+
+instance (
+    Ord a,
+    Ord b
+  ) => Ord (a,b) where
+  compare _ _ = GT
+
+instance (Show a, Show b) =>
+  Show (
+    a,
+    b
+  ) where
+  showsPrec _ _ = showString ""
diff --git a/data/examples/declaration/instance/data-family-instances-gadt-out.hs b/data/examples/declaration/instance/data-family-instances-gadt-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/data-family-instances-gadt-out.hs
@@ -0,0 +1,11 @@
+{-# LANGUAGE GADTSyntax #-}
+{-# LANGUAGE TypeFamilies #-}
+
+data instance Bar Int a where
+  SameBar ::
+    Bar Int
+      Int
+  CloseBar :: Bar Int Double
+  OtherBar ::
+    Bar Int
+      a
diff --git a/data/examples/declaration/instance/data-family-instances-gadt.hs b/data/examples/declaration/instance/data-family-instances-gadt.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/data-family-instances-gadt.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE GADTSyntax #-}
+{-# LANGUAGE TypeFamilies #-}
+data instance Bar Int a where
+    SameBar
+      :: Bar Int
+           Int
+    CloseBar :: Bar Int Double
+    OtherBar
+      :: Bar Int
+           a
diff --git a/data/examples/declaration/instance/data-family-instances-newtype-out.hs b/data/examples/declaration/instance/data-family-instances-newtype-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/data-family-instances-newtype-out.hs
@@ -0,0 +1,7 @@
+{-# LANGUAGE GADTSyntax #-}
+{-# LANGUAGE TypeFamilies #-}
+
+newtype instance Foo [Double]
+  = DoubleListFoo
+      { unDoubleListFoo :: Double
+      }
diff --git a/data/examples/declaration/instance/data-family-instances-newtype.hs b/data/examples/declaration/instance/data-family-instances-newtype.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/data-family-instances-newtype.hs
@@ -0,0 +1,6 @@
+{-# LANGUAGE GADTSyntax #-}
+{-# LANGUAGE TypeFamilies #-}
+newtype instance Foo [Double] = DoubleListFoo {
+    unDoubleListFoo :: Double
+}
+
diff --git a/data/examples/declaration/instance/data-family-instances-out.hs b/data/examples/declaration/instance/data-family-instances-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/data-family-instances-out.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE GADTSyntax #-}
+{-# LANGUAGE TypeFamilies #-}
+
+data instance Foo Int = FooInt Int
+
+data instance
+  Foo
+    [Int]
+  = IntListFoo
+      ( Int,
+        Int
+      )
+      ( Double,
+        Double
+      )
+
+data instance Bar Double a
+  = DoubleBar
+      Double
+      (Bar a)
diff --git a/data/examples/declaration/instance/data-family-instances.hs b/data/examples/declaration/instance/data-family-instances.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/data-family-instances.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE GADTSyntax #-}
+{-# LANGUAGE TypeFamilies #-}
+data instance Foo  Int  = FooInt  Int
+
+data instance
+    Foo [
+        Int
+    ] = IntListFoo (
+        Int,
+        Int
+    ) (
+        Double,
+        Double
+    )
+
+data instance Bar Double a =
+    DoubleBar
+        Double
+        (Bar a)
+
diff --git a/data/examples/declaration/instance/empty-instance-out.hs b/data/examples/declaration/instance/empty-instance-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/empty-instance-out.hs
@@ -0,0 +1,3 @@
+instance Typeable Int
+
+instance Generic Int
diff --git a/data/examples/declaration/instance/empty-instance.hs b/data/examples/declaration/instance/empty-instance.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/empty-instance.hs
@@ -0,0 +1,2 @@
+instance Typeable Int
+instance Generic Int where
diff --git a/data/examples/declaration/instance/instance-sigs-multiple-out.hs b/data/examples/declaration/instance/instance-sigs-multiple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/instance-sigs-multiple-out.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE InstanceSigs #-}
+
+instance Applicative [] where
+
+  pure ::
+    a ->
+    [a]
+  pure a = [a]
+
+  (<*>) ::
+    [a] -> [a] -> [a]
+  (<*>) _ _ = []
diff --git a/data/examples/declaration/instance/instance-sigs-multiple.hs b/data/examples/declaration/instance/instance-sigs-multiple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/instance-sigs-multiple.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE InstanceSigs #-}
+
+instance Applicative [] where
+  pure ::
+       a
+    -> [a]
+  pure a = [a]
+  (<*>)
+    :: [ a ] -> [ a ] -> [ a ]
+  (<*>) _ _ = []
diff --git a/data/examples/declaration/instance/instance-sigs-out.hs b/data/examples/declaration/instance/instance-sigs-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/instance-sigs-out.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE InstanceSigs #-}
+
+instance Eq Int where
+  (==) :: Int -> Int -> Bool
+  (==) _ _ = False
+
+instance Ord Int where
+  compare ::
+    Int ->
+    Int ->
+    Ordering
+  compare
+    _
+    _ =
+      GT
diff --git a/data/examples/declaration/instance/instance-sigs.hs b/data/examples/declaration/instance/instance-sigs.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/instance-sigs.hs
@@ -0,0 +1,16 @@
+{-# LANGUAGE InstanceSigs #-}
+
+instance Eq Int
+  where
+    (==) :: Int -> Int -> Bool
+    (==) _ _ = False
+
+instance Ord Int where
+    compare ::
+           Int
+        -> Int
+        -> Ordering
+    compare
+        _
+        _
+        = GT
diff --git a/data/examples/declaration/instance/multi-parameter-out.hs b/data/examples/declaration/instance/multi-parameter-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/multi-parameter-out.hs
@@ -0,0 +1,7 @@
+instance MonadReader a ((->) a) where ask = id
+
+instance MonadState s (State s) where
+
+  get = State.get
+
+  put = State.put
diff --git a/data/examples/declaration/instance/multi-parameter.hs b/data/examples/declaration/instance/multi-parameter.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/multi-parameter.hs
@@ -0,0 +1,6 @@
+instance MonadReader  a  ((->) a) where ask = id
+
+instance MonadState s (State s)
+  where
+    get = State.get
+    put = State.put
diff --git a/data/examples/declaration/instance/overlappable-instances-out.hs b/data/examples/declaration/instance/overlappable-instances-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/overlappable-instances-out.hs
@@ -0,0 +1,14 @@
+instance {-# OVERLAPPABLE #-} Eq Int where (==) _ _ = False
+
+instance {-# OVERLAPPING #-} Ord Int where
+  compare _ _ = GT
+
+instance {-# OVERLAPS #-} Eq Double where
+  (==) _ _ = False
+
+instance
+  {-# INCOHERENT #-}
+  Ord
+    Double
+  where
+  compare _ _ = GT
diff --git a/data/examples/declaration/instance/overlappable-instances.hs b/data/examples/declaration/instance/overlappable-instances.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/overlappable-instances.hs
@@ -0,0 +1,13 @@
+instance {-# OVERLAPPABLE   #-} Eq Int where (==) _ _ = False
+
+instance
+    {-#   OVERLAPPING #-} Ord Int where compare _ _ = GT
+
+instance {-#  OVERLAPS  #-} Eq Double where
+    (==) _ _ = False
+
+instance
+    {-# INCOHERENT  #-}
+    Ord
+    Double where
+    compare _ _ = GT
diff --git a/data/examples/declaration/instance/single-parameter-out.hs b/data/examples/declaration/instance/single-parameter-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/single-parameter-out.hs
@@ -0,0 +1,11 @@
+instance Monoid Int where (<>) x y = x + y
+
+instance Enum Int where
+
+  fromEnum x = x
+
+  toEnum =
+    \x ->
+      x
+
+instance Foo Int where foo x = x; bar y = y
diff --git a/data/examples/declaration/instance/single-parameter.hs b/data/examples/declaration/instance/single-parameter.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/single-parameter.hs
@@ -0,0 +1,10 @@
+instance Monoid Int where (<>) x y = x+y
+
+instance Enum Int
+  where
+    fromEnum x = x
+    toEnum
+      = \x ->
+        x
+
+instance Foo Int where { foo x = x; bar y = y }
diff --git a/data/examples/declaration/instance/type-family-instances-out.hs b/data/examples/declaration/instance/type-family-instances-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/type-family-instances-out.hs
@@ -0,0 +1,21 @@
+{-# LANGUAGE TypeFamilies #-}
+
+type instance Foo Int = Int
+
+type instance
+  Foo
+    [Int] =
+    ( Int,
+      Int
+    )
+
+type instance Bar Int [Int] Double = (Int, Double)
+
+type instance
+  Bar
+    [Int]
+    [Int]
+    Double =
+    ( Int,
+      Double
+    )
diff --git a/data/examples/declaration/instance/type-family-instances.hs b/data/examples/declaration/instance/type-family-instances.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/instance/type-family-instances.hs
@@ -0,0 +1,21 @@
+{-# LANGUAGE TypeFamilies #-}
+
+type instance Foo  Int  = Int
+
+type instance
+  Foo
+    [Int] = ( Int,
+        Int
+    )
+
+type instance Bar  Int  [Int]  Double = ( Int, Double )
+
+type instance
+  Bar
+    [Int]
+    [Int]
+    Double
+    = (
+      Int,
+      Double
+    )
diff --git a/data/examples/declaration/rewrite-rule/basic1-out.hs b/data/examples/declaration/rewrite-rule/basic1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/basic1-out.hs
@@ -0,0 +1,19 @@
+{-# RULES
+"fold/build" foldr k z (build g) = g k z
+  #-}
+
+{-# RULES
+"fusable/aux"
+  fusable x (aux y) =
+    faux x y
+  #-}
+
+{-# RULES
+"map/map"
+  map
+    f
+    (map g xs) =
+    map
+      (f . g)
+      xs
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/basic1.hs b/data/examples/declaration/rewrite-rule/basic1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/basic1.hs
@@ -0,0 +1,17 @@
+{-# RULES
+"fold/build"  foldr k z (build g) = g k z
+  #-}
+
+{-# RULES
+"fusable/aux"
+    fusable x (aux y) = faux x y
+  #-}
+
+{-# RULES
+"map/map"
+  map f
+    (map g xs) = map
+    (f . g)
+    xs
+  #-}
+
diff --git a/data/examples/declaration/rewrite-rule/basic2-out.hs b/data/examples/declaration/rewrite-rule/basic2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/basic2-out.hs
@@ -0,0 +1,16 @@
+{-# RULES
+"++" xs ++ ys = augment (\c n -> foldr c n xs) ys
+"concat" xs `concat` ys = augment (\c n -> foldr c n xs) ys
+  #-}
+
+{-# RULES
+"++" xs ++ ys = augment (\c n -> foldr c n xs) ys
+"concat" xs `concat` ys = augment (\c n -> foldr c n xs) ys
+"map/Double" fmap f xs = foldr (++) f xs
+  #-}
+
+{-# RULES
+"fb' >\\ (Request b' fb )" forall fb' b' fb.
+  fb' >\\ (Request b' fb) =
+    fb' b' >>= \b -> fb' >\\ fb b
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/basic2.hs b/data/examples/declaration/rewrite-rule/basic2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/basic2.hs
@@ -0,0 +1,16 @@
+{-# RULES
+"++" xs ++ ys = augment (\c n -> foldr c n xs) ys
+"concat" xs `concat` ys = augment (\c n -> foldr c n xs) ys
+  #-}
+
+{-# RULES
+"++" xs ++ ys = augment (\c n -> foldr c n xs) ys;
+"concat" xs `concat` ys = augment (\c n -> foldr c n xs) ys;
+"map/Double" fmap f xs = foldr (++) f xs
+  #-}
+
+{-# RULES
+    "fb' >\\ (Request b' fb )" forall fb' b' fb  .
+        fb' >\\ (Request b' fb ) = fb' b' >>= \b -> fb' >\\ fb  b;
+#-}
+
diff --git a/data/examples/declaration/rewrite-rule/empty-out.hs b/data/examples/declaration/rewrite-rule/empty-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/empty-out.hs
@@ -0,0 +1,3 @@
+{-# RULES
+
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/empty.hs b/data/examples/declaration/rewrite-rule/empty.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/empty.hs
@@ -0,0 +1,2 @@
+{-# RULES
+     #-}
diff --git a/data/examples/declaration/rewrite-rule/forall-out.hs b/data/examples/declaration/rewrite-rule/forall-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/forall-out.hs
@@ -0,0 +1,9 @@
+{-# RULES
+"fold/build" forall k z. foldr k z (build g) = g k z
+  #-}
+
+{-# RULES
+"fusable/aux" forall x y.
+  fusable x (aux y) =
+    faux x y
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/forall.hs b/data/examples/declaration/rewrite-rule/forall.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/forall.hs
@@ -0,0 +1,8 @@
+{-# RULES
+"fold/build" forall k z . foldr k z (build g) = g k z
+  #-}
+
+{-# RULES
+"fusable/aux" forall x y.
+  fusable x (aux y) = faux x y
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/phase-out.hs b/data/examples/declaration/rewrite-rule/phase-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/phase-out.hs
@@ -0,0 +1,23 @@
+{-# RULES
+"map/map" [2]
+  map
+    f
+    (map g xs) =
+    map
+      (f . g)
+      xs
+  #-}
+
+{-# RULES
+"map/map" [1] forall x y z.
+  map
+    f
+    (map g xs) =
+    map
+      (f . g)
+      xs
+  #-}
+
+{-# RULES
+"++" [~1] forall xs ys. xs ++ ys = augment (\c n -> foldr c n xs) ys
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/phase.hs b/data/examples/declaration/rewrite-rule/phase.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/phase.hs
@@ -0,0 +1,19 @@
+{-# RULES
+"map/map" [2]
+  map f
+    (map g xs) = map
+    (f . g)
+    xs
+  #-}
+
+{-# RULES
+"map/map" [1] forall x y z.
+  map f
+    (map g xs) = map
+    (f . g)
+    xs
+  #-}
+
+{-# RULES
+"++" [~1] forall xs ys. xs ++ ys = augment (\c n -> foldr c n xs) ys
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/prelude1-out.hs b/data/examples/declaration/rewrite-rule/prelude1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/prelude1-out.hs
@@ -0,0 +1,18 @@
+{-# RULES
+"map/map" forall f g xs. map f (map g xs) = map (f . g) xs
+"map/append" forall f xs ys. map f (xs ++ ys) = map f xs ++ map f ys
+  #-}
+
+{-# RULES
+"map" [~1] forall f xs. map f xs = build (\c n -> foldr (mapFB c f) n xs)
+"mapList" [1] forall f. foldr (mapFB (:) f) [] = map f
+"mapFB" forall c f g. mapFB (mapFB c f) g = mapFB c (f . g)
+  #-}
+
+{-# RULES
+"map/map" [~2] forall f g xs.
+  map f (map g xs) =
+    map (f . g) xs
+"f" op True y = False
+"g" op True y = False
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/prelude1.hs b/data/examples/declaration/rewrite-rule/prelude1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/prelude1.hs
@@ -0,0 +1,17 @@
+{-# RULES
+"map/map"    forall f g xs.  map f (map g xs) = map (f.g) xs
+"map/append" forall f xs ys. map f (xs ++ ys) = map f xs ++ map f ys
+  #-}
+
+{-# RULES
+"map"       [~1] forall f xs.   map f xs                = build (\c n -> foldr (mapFB c f) n xs)
+"mapList"   [1]  forall f.      foldr (mapFB (:) f) []  = map f
+"mapFB"     forall c f g.       mapFB (mapFB c f) g     = mapFB c (f.g)
+  #-}
+
+{-# RULES
+  "map/map" [~2]  forall f g xs.
+    map f (map g xs) = map (f.g) xs; "f" op True y = False;
+    "g" op True y = False
+#-}
+
diff --git a/data/examples/declaration/rewrite-rule/prelude2-out.hs b/data/examples/declaration/rewrite-rule/prelude2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/prelude2-out.hs
@@ -0,0 +1,31 @@
+{-# RULES
+"fold/build" forall k z (g :: forall b. (a -> b -> b) -> b -> b).
+  foldr k z (build g) =
+    g k z
+"foldr/augment" forall k z xs (g :: forall b. (a -> b -> b) -> b -> b).
+  foldr k z (augment g xs) =
+    g k (foldr k z xs)
+"foldr/id" foldr (:) [] = \x -> x
+"foldr/app" [1] forall ys. foldr (:) ys = \xs -> xs ++ ys
+-- Only activate this from phase 1, because that's
+-- when we disable the rule that expands (++) into foldr
+
+-- The foldr/cons rule looks nice, but it can give disastrously
+-- bloated code when commpiling
+--      array (a,b) [(1,2), (2,2), (3,2), ...very long list... ]
+-- i.e. when there are very very long literal lists
+-- So I've disabled it for now. We could have special cases
+-- for short lists, I suppose.
+-- "foldr/cons" forall k z x xs. foldr k z (x:xs) = k x (foldr k z xs)
+
+"foldr/single" forall k z x. foldr k z [x] = k x z
+"foldr/nil" forall k z. foldr k z [] = z
+"augment/build" forall
+  (g :: forall b. (a -> b -> b) -> b -> b)
+  (h :: forall b. (a -> b -> b) -> b -> b).
+  augment g (build h) =
+    build (\c n -> g c (h c n))
+"augment/nil" forall (g :: forall b. (a -> b -> b) -> b -> b).
+  augment g [] =
+    build g
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/prelude2.hs b/data/examples/declaration/rewrite-rule/prelude2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/prelude2.hs
@@ -0,0 +1,29 @@
+{-# RULES
+"fold/build"    forall k z (g::forall b. (a->b->b) -> b -> b) .
+                foldr k z (build g) = g k z
+
+"foldr/augment" forall k z xs (g::forall b. (a->b->b) -> b -> b) .
+                foldr k z (augment g xs) = g k (foldr k z xs)
+
+"foldr/id"                        foldr (:) [] = \x  -> x
+"foldr/app"     [1] forall ys. foldr (:) ys = \xs -> xs ++ ys
+        -- Only activate this from phase 1, because that's
+        -- when we disable the rule that expands (++) into foldr
+
+-- The foldr/cons rule looks nice, but it can give disastrously
+-- bloated code when commpiling
+--      array (a,b) [(1,2), (2,2), (3,2), ...very long list... ]
+-- i.e. when there are very very long literal lists
+-- So I've disabled it for now. We could have special cases
+-- for short lists, I suppose.
+-- "foldr/cons" forall k z x xs. foldr k z (x:xs) = k x (foldr k z xs)
+
+"foldr/single"  forall k z x. foldr k z [x] = k x z
+"foldr/nil"     forall k z.   foldr k z []  = z
+
+"augment/build" forall (g::forall b. (a->b->b) -> b -> b)
+                       (h::forall b. (a->b->b) -> b -> b) .
+                       augment g (build h) = build (\c n -> g c (h c n))
+"augment/nil"   forall (g::forall b. (a->b->b) -> b -> b) .
+                        augment g [] = build g
+ #-}
diff --git a/data/examples/declaration/rewrite-rule/prelude3-out.hs b/data/examples/declaration/rewrite-rule/prelude3-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/prelude3-out.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE MagicHash #-}
+
+{-# RULES
+"x# `eqChar#` x#" forall x#. x# `eqChar#` x# = True
+"x# `neChar#` x#" forall x#. x# `neChar#` x# = False
+"x# `gtChar#` x#" forall x#. x# `gtChar#` x# = False
+"x# `geChar#` x#" forall x#. x# `geChar#` x# = True
+"x# `leChar#` x#" forall x#. x# `leChar#` x# = True
+"x# `ltChar#` x#" forall x#. x# `ltChar#` x# = False
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/prelude3.hs b/data/examples/declaration/rewrite-rule/prelude3.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/prelude3.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE MagicHash #-}
+
+{-# RULES
+"x# `eqChar#` x#" forall x#. x# `eqChar#` x# = True
+"x# `neChar#` x#" forall x#. x# `neChar#` x# = False
+"x# `gtChar#` x#" forall x#. x# `gtChar#` x# = False
+"x# `geChar#` x#" forall x#. x# `geChar#` x# = True
+"x# `leChar#` x#" forall x#. x# `leChar#` x# = True
+"x# `ltChar#` x#" forall x#. x# `ltChar#` x# = False
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/prelude4-out.hs b/data/examples/declaration/rewrite-rule/prelude4-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/prelude4-out.hs
@@ -0,0 +1,7 @@
+{-# RULES
+"unpack" [~1] forall a. unpackCString # a = build (unpackFoldrCString # a)
+"unpack-list" [1] forall a. unpackFoldrCString # a (:) [] = unpackCString # a
+"unpack-append" forall a n. unpackFoldrCString # a (:) n = unpackAppendCString # a n
+-- There's a built-in rule (in PrelRules.lhs) for
+--      unpackFoldr "foo" c (unpackFoldr "baz" c n)  =  unpackFoldr "foobaz" c n
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/prelude4.hs b/data/examples/declaration/rewrite-rule/prelude4.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/prelude4.hs
@@ -0,0 +1,9 @@
+{-# RULES
+"unpack"       [~1] forall a   . unpackCString# a             = build (unpackFoldrCString# a)
+"unpack-list"  [1]  forall a   . unpackFoldrCString# a (:) [] = unpackCString# a
+"unpack-append"     forall a n . unpackFoldrCString# a (:) n  = unpackAppendCString# a n
+
+-- There's a built-in rule (in PrelRules.lhs) for
+--      unpackFoldr "foo" c (unpackFoldr "baz" c n)  =  unpackFoldr "foobaz" c n
+
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/type-signature-out.hs b/data/examples/declaration/rewrite-rule/type-signature-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/type-signature-out.hs
@@ -0,0 +1,17 @@
+{-# RULES
+"fold/build" forall k z (g :: forall b. (a -> b -> b) -> b -> b). foldr k z (build g) = g k z
+  #-}
+
+{-# RULES
+"fold/build" forall
+  k
+  z
+  ( g ::
+      forall b.
+      (a -> b -> b) ->
+      b ->
+      b
+  ).
+  foldr k z (build g) =
+    g k z
+  #-}
diff --git a/data/examples/declaration/rewrite-rule/type-signature.hs b/data/examples/declaration/rewrite-rule/type-signature.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/rewrite-rule/type-signature.hs
@@ -0,0 +1,12 @@
+{-# RULES
+"fold/build" forall k z (g :: forall b. (a -> b -> b) -> b -> b). foldr k z (build g) = g k z
+  #-}
+
+{-# RULES
+"fold/build"
+  forall k z
+         (g :: forall b.
+           (a -> b -> b) -> b -> b).
+              foldr k z (build g) =
+              g k z
+  #-}
diff --git a/data/examples/declaration/role-annotation/multi-line-out.hs b/data/examples/declaration/role-annotation/multi-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/role-annotation/multi-line-out.hs
@@ -0,0 +1,15 @@
+type role
+  D
+    phantom
+    nominal
+
+type role
+  E
+    _
+    nominal
+
+type role
+  E
+    _
+    nominal
+    phantom
diff --git a/data/examples/declaration/role-annotation/multi-line.hs b/data/examples/declaration/role-annotation/multi-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/role-annotation/multi-line.hs
@@ -0,0 +1,15 @@
+type role
+  D phantom nominal
+
+type
+  role
+    E
+      _
+    nominal
+
+type
+    role
+      E
+        _
+      nominal
+    phantom
diff --git a/data/examples/declaration/role-annotation/single-line-out.hs b/data/examples/declaration/role-annotation/single-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/role-annotation/single-line-out.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE MagicHash #-}
+{-# LANGUAGE RoleAnnotations #-}
+
+type role Ptr representational
+
+type role A nominal nominal
+
+type role B _ phantom
+
+type role C _ _
diff --git a/data/examples/declaration/role-annotation/single-line.hs b/data/examples/declaration/role-annotation/single-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/role-annotation/single-line.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE RoleAnnotations #-}
+{-# LANGUAGE MagicHash #-}
+
+type role Ptr representational
+
+type role A nominal nominal
+
+type role B _ phantom
+type role C _ _
diff --git a/data/examples/declaration/signature/complete/complete-out.hs b/data/examples/declaration/signature/complete/complete-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/complete/complete-out.hs
@@ -0,0 +1,10 @@
+{-# COMPLETE A, B, C :: Foo #-}
+
+{-# COMPLETE A, B #-}
+
+{-# COMPLETE
+  A,
+  B,
+  C ::
+    Foo
+  #-}
diff --git a/data/examples/declaration/signature/complete/complete.hs b/data/examples/declaration/signature/complete/complete.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/complete/complete.hs
@@ -0,0 +1,13 @@
+{-#   ComPlETe       A  , B, C::         Foo
+
+  #-}
+
+{-#    COMPLETE          A , B
+   #-}
+
+{-#   ComPlETE
+      A  , 
+    B, C
+
+
+    ::         Foo#-}
diff --git a/data/examples/declaration/signature/fixity/infix-out.hs b/data/examples/declaration/signature/fixity/infix-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/fixity/infix-out.hs
@@ -0,0 +1,3 @@
+infix 0 <?>
+
+infix 9 <^-^>
diff --git a/data/examples/declaration/signature/fixity/infix.hs b/data/examples/declaration/signature/fixity/infix.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/fixity/infix.hs
@@ -0,0 +1,2 @@
+infix 0 <?>
+infix 9 <^-^>
diff --git a/data/examples/declaration/signature/fixity/infixl-out.hs b/data/examples/declaration/signature/fixity/infixl-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/fixity/infixl-out.hs
@@ -0,0 +1,3 @@
+infixl 8 ***
+
+infixl 0 $, *, +, &&, **
diff --git a/data/examples/declaration/signature/fixity/infixl.hs b/data/examples/declaration/signature/fixity/infixl.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/fixity/infixl.hs
@@ -0,0 +1,2 @@
+infixl 8 ***
+infixl 0 $, *, +, &&, **
diff --git a/data/examples/declaration/signature/fixity/infixr-out.hs b/data/examples/declaration/signature/fixity/infixr-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/fixity/infixr-out.hs
@@ -0,0 +1,3 @@
+infixr 8 `Foo`
+
+infixr 0 ***, &&&
diff --git a/data/examples/declaration/signature/fixity/infixr.hs b/data/examples/declaration/signature/fixity/infixr.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/fixity/infixr.hs
@@ -0,0 +1,2 @@
+infixr 8 `Foo`
+infixr 0 ***, &&&
diff --git a/data/examples/declaration/signature/inline/conlike-out.hs b/data/examples/declaration/signature/inline/conlike-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/inline/conlike-out.hs
@@ -0,0 +1,7 @@
+foo :: Int
+foo = 5
+{-# INLINE CONLIKE foo #-}
+
+bar :: Int
+bar = 6
+{-# INLINE CONLIKE bar #-}
diff --git a/data/examples/declaration/signature/inline/conlike.hs b/data/examples/declaration/signature/inline/conlike.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/inline/conlike.hs
@@ -0,0 +1,7 @@
+foo :: Int
+foo = 5
+{-# INLINE CONLIKE foo #-}
+
+bar :: Int
+bar = 6
+{-# INLINE CONLIKE bar #-}
diff --git a/data/examples/declaration/signature/inline/inline-out.hs b/data/examples/declaration/signature/inline/inline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/inline/inline-out.hs
@@ -0,0 +1,15 @@
+foo :: Int -> Int
+foo = id
+{-# INLINE foo #-}
+
+{-# INLINE [2] bar #-}
+bar :: Int -> Int
+bar = id
+
+baz :: Int -> Int
+baz = id
+{-# INLINE [~2] baz #-}
+
+reVector :: Bundle u a -> Bundle v a
+{-# INLINE reVector #-}
+reVector = M.reVector
diff --git a/data/examples/declaration/signature/inline/inline.hs b/data/examples/declaration/signature/inline/inline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/inline/inline.hs
@@ -0,0 +1,18 @@
+foo :: Int -> Int
+foo = id
+
+{-# INLINE   foo   #-}
+
+{-# INLINE [2] bar    #-}
+
+bar :: Int -> Int
+bar = id
+
+baz :: Int -> Int
+baz = id
+{-#   INLINE [~2] baz #-}
+
+reVector :: Bundle u a -> Bundle v a
+
+{-# INLINE reVector #-}
+reVector = M.reVector
diff --git a/data/examples/declaration/signature/inline/inlineable-out.hs b/data/examples/declaration/signature/inline/inlineable-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/inline/inlineable-out.hs
@@ -0,0 +1,11 @@
+foo :: Int -> Int
+foo = id
+{-# INLINEABLE foo #-}
+
+{-# INLINEABLE [2] bar #-}
+bar :: Int -> Int
+bar = id
+
+baz :: Int -> Int
+baz = id
+{-# INLINEABLE [~2] baz #-}
diff --git a/data/examples/declaration/signature/inline/inlineable.hs b/data/examples/declaration/signature/inline/inlineable.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/inline/inlineable.hs
@@ -0,0 +1,13 @@
+foo :: Int -> Int
+foo = id
+
+{-#   INLINEABLE  foo   #-}
+
+{-# INLINEABLE [2]    bar #-}
+
+bar :: Int -> Int
+bar = id
+
+baz :: Int -> Int
+baz = id
+{-# INLINEABLE [~2]  baz #-}
diff --git a/data/examples/declaration/signature/inline/noinline-out.hs b/data/examples/declaration/signature/inline/noinline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/inline/noinline-out.hs
@@ -0,0 +1,11 @@
+foo :: Int -> Int
+foo = id
+{-# NOINLINE foo #-}
+
+{-# NOINLINE [2] bar #-}
+bar :: Int -> Int
+bar = id
+
+baz :: Int -> Int
+baz = id
+{-# NOINLINE [~2] baz #-}
diff --git a/data/examples/declaration/signature/inline/noinline.hs b/data/examples/declaration/signature/inline/noinline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/inline/noinline.hs
@@ -0,0 +1,13 @@
+foo :: Int -> Int
+foo = id
+{-# NOINLINE foo #-}
+
+{-# NOINLINE [2] bar    #-}
+
+bar :: Int -> Int
+bar = id
+
+baz :: Int -> Int
+baz = id
+
+{-#   NOINLINE    [~2] baz #-}
diff --git a/data/examples/declaration/signature/minimal/minimal-out.hs b/data/examples/declaration/signature/minimal/minimal-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/minimal/minimal-out.hs
@@ -0,0 +1,16 @@
+class Foo a where
+
+  {-# MINIMAL (==) | ((/=), foo) #-}
+
+  {-# MINIMAL
+    a
+    | ( b, c, d
+        | e,
+          f
+      )
+      | g
+    #-}
+
+  (==) :: a -> a -> Bool
+
+  (/=) :: a -> a -> Bool
diff --git a/data/examples/declaration/signature/minimal/minimal.hs b/data/examples/declaration/signature/minimal/minimal.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/minimal/minimal.hs
@@ -0,0 +1,10 @@
+class Foo a where
+
+  {-# MINIMAL     (==)   |(  (/=) ,       foo) #-}
+
+  {-#    MINIMAL a | (b , c      , d | e
+     , f)
+    |   g  #-}
+
+  (==) :: a -> a -> Bool
+  (/=) :: a -> a -> Bool
diff --git a/data/examples/declaration/signature/pattern/multiline-out.hs b/data/examples/declaration/signature/pattern/multiline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/pattern/multiline-out.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+pattern Arrow ::
+  Type ->
+  Type ->
+  Type
+
+pattern
+  Foo,
+  Bar ::
+    Type -> Type -> Type
+
+pattern
+  TypeSignature,
+  FunctionBody,
+  PatternSignature,
+  WarningPragma ::
+    [RdrName] ->
+    HsDecl GhcPs
diff --git a/data/examples/declaration/signature/pattern/multiline.hs b/data/examples/declaration/signature/pattern/multiline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/pattern/multiline.hs
@@ -0,0 +1,13 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+pattern Arrow :: Type
+  -> Type -> Type
+
+pattern Foo, Bar ::
+  Type -> Type -> Type
+
+pattern TypeSignature
+      , FunctionBody
+      , PatternSignature
+      , WarningPragma :: [RdrName]
+        -> HsDecl GhcPs
diff --git a/data/examples/declaration/signature/pattern/single-line-out.hs b/data/examples/declaration/signature/pattern/single-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/pattern/single-line-out.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+pattern Arrow :: Type -> Type -> Type
+
+pattern Foo, Bar :: Type -> Type -> Type
diff --git a/data/examples/declaration/signature/pattern/single-line.hs b/data/examples/declaration/signature/pattern/single-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/pattern/single-line.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+pattern Arrow :: Type -> Type -> Type
+
+pattern Foo, Bar :: Type -> Type -> Type
diff --git a/data/examples/declaration/signature/set-cost-centre/set-cost-centre-out.hs b/data/examples/declaration/signature/set-cost-centre/set-cost-centre-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/set-cost-centre/set-cost-centre-out.hs
@@ -0,0 +1,14 @@
+f x y = g (x + y)
+  where
+    g z = z
+    {-# SCC g #-}
+{-# SCC f #-}
+
+withString x y = x + y
+{-# SCC withString "cost_centre_name" #-}
+
+withString' x y = x + y
+{-# SCC
+  withString'
+  "cost_centre_name"
+  #-}
diff --git a/data/examples/declaration/signature/set-cost-centre/set-cost-centre.hs b/data/examples/declaration/signature/set-cost-centre/set-cost-centre.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/set-cost-centre/set-cost-centre.hs
@@ -0,0 +1,16 @@
+f x y = g (x + y)
+  where
+    g z = z
+    {-# SCC g #-}
+
+{-# SCC f #-}
+
+withString x y = x + y
+
+{-# SCC withString "cost_centre_name" #-}
+
+withString' x y = x + y
+
+{-# SCC withString'
+  "cost_centre_name"
+  #-}
diff --git a/data/examples/declaration/signature/specialize/specialize-instance-out.hs b/data/examples/declaration/signature/specialize/specialize-instance-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/specialize/specialize-instance-out.hs
@@ -0,0 +1,18 @@
+data Foo a = Foo a
+
+data VT v m r = VT v m r
+
+instance (Eq a) => Eq (Foo a) where
+
+  {-# SPECIALIZE instance Eq (Foo [(Int, Bar)]) #-}
+
+  (==) (Foo a) (Foo b) = (==) a b
+
+instance (Num r, V.Vector v r, Factored m r) => Num (VT v m r) where
+
+  {-# SPECIALIZE instance
+    ( Factored m Int => Num (VT U.Vector m Int)
+    )
+    #-}
+
+  VT x + VT y = VT $ V.zipWith (+) x y
diff --git a/data/examples/declaration/signature/specialize/specialize-instance.hs b/data/examples/declaration/signature/specialize/specialize-instance.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/specialize/specialize-instance.hs
@@ -0,0 +1,11 @@
+data Foo a = Foo a
+data VT v m r = VT v m r
+
+instance (Eq a) => Eq (Foo a) where
+  {-# SPECIALIZE instance Eq (Foo [(Int, Bar)]) #-}
+  (==) (Foo a) (Foo b) = (==) a b
+
+instance (Num r, V.Vector v r, Factored m r) => Num (VT v m r) where
+  {-# SPECIALIZE instance (
+                 Factored m Int => Num (VT U.Vector m Int)) #-}
+  VT x + VT y = VT $ V.zipWith (+) x y
diff --git a/data/examples/declaration/signature/specialize/specialize-out.hs b/data/examples/declaration/signature/specialize/specialize-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/specialize/specialize-out.hs
@@ -0,0 +1,24 @@
+foo :: Num a => a -> a
+foo = id
+{-# SPECIALIZE foo :: Int -> Int #-}
+{-# SPECIALIZE INLINE foo :: Float -> Float #-}
+
+{-# SPECIALIZE NOINLINE [2] bar :: Int -> Int #-}
+bar :: Num a => a -> a
+bar = id
+
+baz :: Num a => a -> a
+baz = id
+{-# SPECIALIZE [~2] baz ::
+  Int ->
+  Int
+  #-}
+
+{-# SPECIALIZE fits13Bits :: Int -> Bool, Integer -> Bool #-}
+{-# SPECIALIZE fits13Bits ::
+  Int ->
+  Bool,
+  Integer -> Bool
+  #-}
+fits13Bits :: Integral a => a -> Bool
+fits13Bits x = x >= -4096 && x < 4096
diff --git a/data/examples/declaration/signature/specialize/specialize.hs b/data/examples/declaration/signature/specialize/specialize.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/specialize/specialize.hs
@@ -0,0 +1,24 @@
+foo :: Num a => a -> a
+foo = id
+
+{-# SPECIALIZE foo :: Int -> Int #-}
+{-# SPECIALIZE INLINE foo :: Float -> Float #-}
+
+{-# SPECIALIZE NOINLINE [2] bar :: Int -> Int #-}
+
+bar :: Num a => a -> a
+bar = id
+
+baz :: Num a => a -> a
+baz = id
+{-# SPECIALIZE [~2] baz
+      :: Int
+      -> Int #-}
+
+{-# SPECIALIZE fits13Bits :: Int -> Bool, Integer -> Bool #-}
+{-# SPECIALIZE fits13Bits
+        :: Int
+        -> Bool
+        , Integer -> Bool #-}
+fits13Bits :: Integral a => a -> Bool
+fits13Bits x = x >= -4096 && x < 4096
diff --git a/data/examples/declaration/signature/type/arguments-out.hs b/data/examples/declaration/signature/type/arguments-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/arguments-out.hs
@@ -0,0 +1,16 @@
+{-# LANGUAGE RankNTypes #-}
+
+functionName ::
+  (C1, C2, C3, C4, C5) =>
+  a ->
+  b ->
+  ( forall a.
+    (C6, C7) =>
+    LongDataTypeName ->
+    a ->
+    AnotherLongDataTypeName ->
+    b ->
+    c
+  ) ->
+  (c -> d) ->
+  (a, b, c, d)
diff --git a/data/examples/declaration/signature/type/arguments.hs b/data/examples/declaration/signature/type/arguments.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/arguments.hs
@@ -0,0 +1,16 @@
+{-# LANGUAGE RankNTypes #-}
+
+functionName
+  :: (C1, C2, C3, C4, C5)
+  => a
+  -> b
+  -> (forall a.
+        (C6, C7)
+     => LongDataTypeName
+     -> a
+     -> AnotherLongDataTypeName
+     -> b
+     -> c
+     )
+  -> (c -> d)
+  -> (a, b, c, d)
diff --git a/data/examples/declaration/signature/type/context-multi-line-out.hs b/data/examples/declaration/signature/type/context-multi-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/context-multi-line-out.hs
@@ -0,0 +1,10 @@
+functionName ::
+  ( C1,
+    C2,
+    C3
+  ) =>
+  a ->
+  b ->
+  c ->
+  d ->
+  (a, b, c, d)
diff --git a/data/examples/declaration/signature/type/context-multi-line.hs b/data/examples/declaration/signature/type/context-multi-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/context-multi-line.hs
@@ -0,0 +1,10 @@
+functionName
+  :: ( C1
+     , C2
+     , C3
+     )
+  => a
+  -> b
+  -> c
+  -> d
+  -> (a, b, c, d)
diff --git a/data/examples/declaration/signature/type/context-single-line-out.hs b/data/examples/declaration/signature/type/context-single-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/context-single-line-out.hs
@@ -0,0 +1,7 @@
+functionName ::
+  (C1, C2, C3) =>
+  a ->
+  b ->
+  c ->
+  d ->
+  (a, b, c, d)
diff --git a/data/examples/declaration/signature/type/context-single-line.hs b/data/examples/declaration/signature/type/context-single-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/context-single-line.hs
@@ -0,0 +1,7 @@
+functionName
+  :: (C1, C2, C3)
+  => a
+  -> b
+  -> c
+  -> d
+  -> (a, b, c, d)
diff --git a/data/examples/declaration/signature/type/infix-promoted-type-constructor-out.hs b/data/examples/declaration/signature/type/infix-promoted-type-constructor-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/infix-promoted-type-constructor-out.hs
@@ -0,0 +1,3 @@
+fun1 :: Def ('[Ref s (Stored Uint32), IBool] 'T.:-> IBool)
+
+fun2 :: Def ('[Ref s (Stored Uint32), IBool] ':-> IBool)
diff --git a/data/examples/declaration/signature/type/infix-promoted-type-constructor.hs b/data/examples/declaration/signature/type/infix-promoted-type-constructor.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/infix-promoted-type-constructor.hs
@@ -0,0 +1,2 @@
+fun1 :: Def ('[ Ref s (Stored Uint32), IBool] 'T.:-> IBool)
+fun2 :: Def ('[ Ref s (Stored Uint32), IBool] ':-> IBool)
diff --git a/data/examples/declaration/signature/type/long-function-name-out.hs b/data/examples/declaration/signature/type/long-function-name-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/long-function-name-out.hs
@@ -0,0 +1,6 @@
+longFunctionName ::
+  a ->
+  b ->
+  c ->
+  d ->
+  (a, b, c, d)
diff --git a/data/examples/declaration/signature/type/long-function-name.hs b/data/examples/declaration/signature/type/long-function-name.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/long-function-name.hs
@@ -0,0 +1,6 @@
+longFunctionName
+  :: a
+  -> b
+  -> c
+  -> d
+  -> (a, b, c, d)
diff --git a/data/examples/declaration/signature/type/long-multiline-applications-out.hs b/data/examples/declaration/signature/type/long-multiline-applications-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/long-multiline-applications-out.hs
@@ -0,0 +1,15 @@
+functionName ::
+  (C1, C2, C3, C4, C5) =>
+  a ->
+  b ->
+  ( LongDataTypeName
+      AnotherLongDataTypeName
+      AnotherLongDataTypeName2
+      AnotherLongDataTypeName3 ->
+    a ->
+    AnotherLongDataTypeName4 ->
+    b ->
+    c
+  ) ->
+  (c -> d) ->
+  (a, b, c, d)
diff --git a/data/examples/declaration/signature/type/long-multiline-applications.hs b/data/examples/declaration/signature/type/long-multiline-applications.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/long-multiline-applications.hs
@@ -0,0 +1,15 @@
+functionName
+  :: (C1, C2, C3, C4, C5)
+  => a
+  -> b
+  -> (  LongDataTypeName
+          AnotherLongDataTypeName
+          AnotherLongDataTypeName2
+          AnotherLongDataTypeName3
+     -> a
+     -> AnotherLongDataTypeName4
+     -> b
+     -> c
+     )
+  -> (c -> d)
+  -> (a, b, c, d)
diff --git a/data/examples/declaration/signature/type/multi-value-out.hs b/data/examples/declaration/signature/type/multi-value-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/multi-value-out.hs
@@ -0,0 +1,10 @@
+foo, bar :: Int
+foo = 1
+bar = 2
+
+foo,
+  bar,
+  baz ::
+    Int
+bar = 2
+baz = 3
diff --git a/data/examples/declaration/signature/type/multi-value.hs b/data/examples/declaration/signature/type/multi-value.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/multi-value.hs
@@ -0,0 +1,9 @@
+foo, bar :: Int
+foo = 1
+bar = 2
+
+foo,
+  bar,
+    baz :: Int
+bar = 2
+baz = 3
diff --git a/data/examples/declaration/signature/type/unicode-out.hs b/data/examples/declaration/signature/type/unicode-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/unicode-out.hs
@@ -0,0 +1,4 @@
+{-# LANGUAGE UnicodeSyntax #-}
+
+foo :: forall a. Show a => a -> String
+foo = const ()
diff --git a/data/examples/declaration/signature/type/unicode.hs b/data/examples/declaration/signature/type/unicode.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/signature/type/unicode.hs
@@ -0,0 +1,4 @@
+{-# LANGUAGE UnicodeSyntax #-}
+
+foo ∷ ∀a. Show a ⇒ a → String
+foo = const ()
diff --git a/data/examples/declaration/splice/bracket-declaration-out.hs b/data/examples/declaration/splice/bracket-declaration-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/bracket-declaration-out.hs
@@ -0,0 +1,26 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+[d|data T a where Foo :: T ()|]
+
+foo =
+  [d|
+    foo :: Int -> Char
+
+    bar = 42
+    |]
+
+[d|
+  data T = T
+    deriving (Eq, Ord, Enum, Bounded, Show)
+  |]
+
+$(do [d|baz = baz|])
+
+$(singletons [d|data T = T deriving (Eq, Ord, Enum, Bounded, Show)|])
+
+$( singletons
+     [d|
+       data T = T
+         deriving (Eq, Ord, Enum, Bounded, Show)
+       |]
+ )
diff --git a/data/examples/declaration/splice/bracket-declaration.hs b/data/examples/declaration/splice/bracket-declaration.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/bracket-declaration.hs
@@ -0,0 +1,22 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+[d| data T a where Foo :: T () |]
+
+foo = [d|
+           foo:: Int       -> Char
+           bar = 42
+  |]
+
+[d|
+    data T = T
+      deriving (Eq, Ord, Enum, Bounded, Show)
+  |]
+
+$( do [d| baz = baz |] )
+
+$(singletons [d| data T = T deriving (Eq, Ord, Enum, Bounded, Show) |])
+
+$(singletons [d|
+  data T = T
+    deriving (Eq, Ord, Enum, Bounded, Show)
+ |])
diff --git a/data/examples/declaration/splice/bracket-out.hs b/data/examples/declaration/splice/bracket-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/bracket-out.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+foo =
+  [|
+    foo bar
+    |]
+
+foo =
+  [e|
+    foo bar
+    |]
+
+foo = [t|Char|]
+
+foo =
+  [||
+  foo bar
+  ||]
diff --git a/data/examples/declaration/splice/bracket.hs b/data/examples/declaration/splice/bracket.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/bracket.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+foo   = [|      foo bar
+  |]
+
+foo = [e| foo bar
+  |]
+
+foo = [t|       Char |]
+
+foo = [|| foo bar
+  ||]
diff --git a/data/examples/declaration/splice/quasiquote-out.hs b/data/examples/declaration/splice/quasiquote-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/quasiquote-out.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+x = [foo|    foo bar   |]
+
+x =
+  [e|    foo
+ bar  {- -}
+  |]
+
+[d|    foo bar
+
+|]
diff --git a/data/examples/declaration/splice/quasiquote.hs b/data/examples/declaration/splice/quasiquote.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/quasiquote.hs
@@ -0,0 +1,11 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+x = [foo|    foo bar   |]
+
+x = [e|    foo
+ bar  {- -}
+  |]
+
+[d|    foo bar
+
+|]
diff --git a/data/examples/declaration/splice/quotes-out.hs b/data/examples/declaration/splice/quotes-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/quotes-out.hs
@@ -0,0 +1,17 @@
+foo = ''R
+
+bar = 'foo
+
+bar' = 'foo_bar
+
+baz = ''(:#)
+
+baz' = ''(Foo.Bar.:#)
+
+equals = ''(==)
+
+unit = ''()
+
+list = ''[]
+
+quolified = ''Semigroup.Option
diff --git a/data/examples/declaration/splice/quotes.hs b/data/examples/declaration/splice/quotes.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/quotes.hs
@@ -0,0 +1,17 @@
+foo = ''R
+
+bar = 'foo
+
+bar' = 'foo_bar
+
+baz = ''(:#)
+
+baz' = ''(Foo.Bar.:#)
+
+equals = ''(==)
+
+unit = ''()
+
+list = ''[]
+
+quolified = ''Semigroup.Option
diff --git a/data/examples/declaration/splice/splice-decl-out.hs b/data/examples/declaration/splice/splice-decl-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/splice-decl-out.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+$(foo bar)
+
+$foo
+
+$$(foo bar)
+
+$$foo
+
+foo bar
+
+[|booya|]
+
+-- TemplateHaskell allows Q () at the top level
+do
+  pure []
diff --git a/data/examples/declaration/splice/splice-decl.hs b/data/examples/declaration/splice/splice-decl.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/splice-decl.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+$(  foo       bar)
+
+$foo
+
+$$(  foo       bar)
+
+$$foo
+
+foo bar
+
+[|booya|]
+
+-- TemplateHaskell allows Q () at the top level
+do
+  pure []
+
diff --git a/data/examples/declaration/splice/typed-splice-out.hs b/data/examples/declaration/splice/typed-splice-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/typed-splice-out.hs
@@ -0,0 +1,7 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+x =
+  $$( foo bar
+    )
+
+x = $$foo
diff --git a/data/examples/declaration/splice/typed-splice.hs b/data/examples/declaration/splice/typed-splice.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/typed-splice.hs
@@ -0,0 +1,6 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+x      =    $$(   foo  bar 
+  )
+
+x     =     $$foo
diff --git a/data/examples/declaration/splice/untyped-splice-out.hs b/data/examples/declaration/splice/untyped-splice-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/untyped-splice-out.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+x = $(foo bar)
+
+x =
+  $( foo
+       bar
+   )
+
+x = $foo
diff --git a/data/examples/declaration/splice/untyped-splice.hs b/data/examples/declaration/splice/untyped-splice.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/splice/untyped-splice.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE TemplateHaskell #-}
+x      =    $(      foo bar     )
+
+x = $(   
+  foo  
+      bar      )
+
+x = $foo
diff --git a/data/examples/declaration/type-families/closed-type-family/infix-out.hs b/data/examples/declaration/type-families/closed-type-family/infix-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/closed-type-family/infix-out.hs
@@ -0,0 +1,11 @@
+type family (x :: N) + (y :: N) :: N where
+  'Zero + y = y
+  'Succ n + y = 'Succ (n + y)
+
+type family (x :: N) `LEQ` (y :: N) :: Bool where
+  'Zero `LEQ` y = 'True
+  'Succ n `LEQ` 'Zero = 'False
+  'Succ n `LEQ` 'Succ m = n `LEQ` m
+
+type family ((x :: N) `Weird` (y :: N)) (z :: N) :: Bool where
+  'Zero `Weird` 'Zero 'Zero = 'True
diff --git a/data/examples/declaration/type-families/closed-type-family/infix.hs b/data/examples/declaration/type-families/closed-type-family/infix.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/closed-type-family/infix.hs
@@ -0,0 +1,11 @@
+type family (x :: N) + (y :: N) :: N where
+  'Zero + y = y
+  'Succ n + y = 'Succ (n + y)
+
+type family (x :: N) `LEQ` (y :: N) :: Bool where
+  'Zero `LEQ` y = 'True
+  'Succ n `LEQ` 'Zero = 'False
+  'Succ n `LEQ` 'Succ m = n `LEQ` m
+
+type family ((x :: N) `Weird` (y :: N)) (z :: N) :: Bool where
+  'Zero `Weird` 'Zero 'Zero = 'True
diff --git a/data/examples/declaration/type-families/closed-type-family/injective-out.hs b/data/examples/declaration/type-families/closed-type-family/injective-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/closed-type-family/injective-out.hs
@@ -0,0 +1,5 @@
+type family Id a = result | result -> a where
+  Id a = a
+
+type family G (a :: k) b c = foo | foo -> k b where
+  G a b c = (a, b)
diff --git a/data/examples/declaration/type-families/closed-type-family/injective.hs b/data/examples/declaration/type-families/closed-type-family/injective.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/closed-type-family/injective.hs
@@ -0,0 +1,4 @@
+type family Id a = result | result -> a where
+  Id a = a
+type family G (a :: k) b c = foo | foo -> k b where
+  G a b c = (a, b)
diff --git a/data/examples/declaration/type-families/closed-type-family/multi-line-out.hs b/data/examples/declaration/type-families/closed-type-family/multi-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/closed-type-family/multi-line-out.hs
@@ -0,0 +1,24 @@
+type family
+  Id a =
+    result
+    | result -> a where
+  Id a =
+    a
+
+type family
+  G
+    (a :: k)
+    b
+    c =
+    foo
+    | foo -> k b where
+  G a b c =
+    (a, b)
+
+type family
+  F a ::
+    * -> * where
+  F Int = Double
+  F Bool =
+    Char
+  F a = String
diff --git a/data/examples/declaration/type-families/closed-type-family/multi-line.hs b/data/examples/declaration/type-families/closed-type-family/multi-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/closed-type-family/multi-line.hs
@@ -0,0 +1,14 @@
+type family Id a
+    = result | result -> a where
+  Id a
+    = a
+type family G (a :: k)
+              b c = foo | foo -> k b where
+  G a b c =
+    (a, b)
+type family F a
+  :: * -> * where
+  F Int  = Double
+  F Bool =
+           Char
+  F a    = String
diff --git a/data/examples/declaration/type-families/closed-type-family/no-annotation-out.hs b/data/examples/declaration/type-families/closed-type-family/no-annotation-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/closed-type-family/no-annotation-out.hs
@@ -0,0 +1,4 @@
+type family F a where
+  F Int = Double
+  F Bool = Char
+  F a = String
diff --git a/data/examples/declaration/type-families/closed-type-family/no-annotation.hs b/data/examples/declaration/type-families/closed-type-family/no-annotation.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/closed-type-family/no-annotation.hs
@@ -0,0 +1,4 @@
+type family F a where
+  F Int  = Double
+  F Bool = Char
+  F a    = String
diff --git a/data/examples/declaration/type-families/closed-type-family/simple-out.hs b/data/examples/declaration/type-families/closed-type-family/simple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/closed-type-family/simple-out.hs
@@ -0,0 +1,7 @@
+module Main where
+
+-- | Documentation.
+type family F a :: * -> * where
+  F Int = Double
+  F Bool = Char
+  F a = String
diff --git a/data/examples/declaration/type-families/closed-type-family/simple.hs b/data/examples/declaration/type-families/closed-type-family/simple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/closed-type-family/simple.hs
@@ -0,0 +1,8 @@
+module Main where
+
+-- | Documentation.
+
+type family F a :: * -> * where
+  F Int  = Double
+  F Bool = Char
+  F a    = String
diff --git a/data/examples/declaration/type-families/data-family/no-annotation-out.hs b/data/examples/declaration/type-families/data-family/no-annotation-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/data-family/no-annotation-out.hs
@@ -0,0 +1,4 @@
+module Main where
+
+-- | Documentation.
+data family Array e
diff --git a/data/examples/declaration/type-families/data-family/no-annotation.hs b/data/examples/declaration/type-families/data-family/no-annotation.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/data-family/no-annotation.hs
@@ -0,0 +1,5 @@
+module Main where
+
+-- | Documentation.
+
+data family Array e
diff --git a/data/examples/declaration/type-families/data-family/simple-out.hs b/data/examples/declaration/type-families/data-family/simple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/data-family/simple-out.hs
@@ -0,0 +1,4 @@
+module Main where
+
+-- | Documentation.
+data family GMap k :: Type -> Type
diff --git a/data/examples/declaration/type-families/data-family/simple.hs b/data/examples/declaration/type-families/data-family/simple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/data-family/simple.hs
@@ -0,0 +1,5 @@
+module Main where
+
+-- | Documentation.
+
+data family GMap k :: Type -> Type
diff --git a/data/examples/declaration/type-families/type-family/injective-out.hs b/data/examples/declaration/type-families/type-family/injective-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/type-family/injective-out.hs
@@ -0,0 +1,3 @@
+type family Id a = r | r -> a
+
+type family F a b c = d | d -> a c b
diff --git a/data/examples/declaration/type-families/type-family/injective.hs b/data/examples/declaration/type-families/type-family/injective.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/type-family/injective.hs
@@ -0,0 +1,2 @@
+type family Id a = r | r -> a
+type family F a b c = d | d -> a c b
diff --git a/data/examples/declaration/type-families/type-family/no-annotation-out.hs b/data/examples/declaration/type-families/type-family/no-annotation-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/type-family/no-annotation-out.hs
@@ -0,0 +1,4 @@
+module Main where
+
+-- | Documentation.
+type family F a b :: Type -> Type
diff --git a/data/examples/declaration/type-families/type-family/no-annotation.hs b/data/examples/declaration/type-families/type-family/no-annotation.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/type-family/no-annotation.hs
@@ -0,0 +1,5 @@
+module Main where
+
+-- | Documentation.
+
+type family F a b :: Type -> Type
diff --git a/data/examples/declaration/type-families/type-family/simple-out.hs b/data/examples/declaration/type-families/type-family/simple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/type-family/simple-out.hs
@@ -0,0 +1,4 @@
+module Main where
+
+-- | Documentation.
+type family Elem c :: Type
diff --git a/data/examples/declaration/type-families/type-family/simple.hs b/data/examples/declaration/type-families/type-family/simple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-families/type-family/simple.hs
@@ -0,0 +1,5 @@
+module Main where
+
+-- | Documentation.
+
+type family Elem c :: Type
diff --git a/data/examples/declaration/type-synonyms/multi-line-out.hs b/data/examples/declaration/type-synonyms/multi-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-synonyms/multi-line-out.hs
@@ -0,0 +1,18 @@
+type Foo a b c =
+  Bar c a b
+
+type Foo
+  a
+  b
+  c =
+  Bar c a b
+
+type Foo =
+  Bar
+    Baz
+    Quux
+
+type API =
+  "route1" :> ApiRoute1
+    :<|> "route2" :> ApiRoute2 -- comment here
+    :<|> OmitDocs :> "i" :> ASomething API
diff --git a/data/examples/declaration/type-synonyms/multi-line.hs b/data/examples/declaration/type-synonyms/multi-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-synonyms/multi-line.hs
@@ -0,0 +1,17 @@
+type Foo a b c
+  = Bar c a b
+
+type Foo
+  a
+  b c
+  = Bar c a b
+
+type Foo =
+  Bar
+    Baz
+      Quux
+
+type API
+  = "route1" :> ApiRoute1
+      :<|> "route2" :> ApiRoute2 -- comment here
+      :<|> OmitDocs :> "i" :> ASomething API
diff --git a/data/examples/declaration/type-synonyms/simple-out.hs b/data/examples/declaration/type-synonyms/simple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-synonyms/simple-out.hs
@@ -0,0 +1,8 @@
+module Main where
+
+-- | Documentation.
+type Foo a b c = Bar c a b
+
+type a ~> b = TyFun a b -> Type
+
+type (a :+: b) c d e = ()
diff --git a/data/examples/declaration/type-synonyms/simple.hs b/data/examples/declaration/type-synonyms/simple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type-synonyms/simple.hs
@@ -0,0 +1,9 @@
+module Main where
+
+-- | Documentation.
+
+type Foo a b c = Bar c a b
+
+type a ~> b = TyFun a b -> Type
+
+type (a :+: b) c d e = ()
diff --git a/data/examples/declaration/type/forall-out.hs b/data/examples/declaration/type/forall-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/forall-out.hs
@@ -0,0 +1,4 @@
+type CoerceLocalSig m m' =
+  forall r a.
+  LocalSig m r a ->
+  LocalSig m' r a
diff --git a/data/examples/declaration/type/forall.hs b/data/examples/declaration/type/forall.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/forall.hs
@@ -0,0 +1,4 @@
+type CoerceLocalSig m m' =
+  forall r a.
+  LocalSig m  r a ->
+  LocalSig m' r a
diff --git a/data/examples/declaration/type/lits-out.hs b/data/examples/declaration/type/lits-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/lits-out.hs
@@ -0,0 +1,6 @@
+type A = "foo"
+
+type B =
+  "foo\
+  \bar" ->
+  ()
diff --git a/data/examples/declaration/type/lits.hs b/data/examples/declaration/type/lits.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/lits.hs
@@ -0,0 +1,4 @@
+type A = "foo"
+
+type B = "foo\
+         \bar" -> ()
diff --git a/data/examples/declaration/type/misc-kind-signatures-out.hs b/data/examples/declaration/type/misc-kind-signatures-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/misc-kind-signatures-out.hs
@@ -0,0 +1,5 @@
+instance DemoteNodeTypes ('[] :: [NodeType]) where
+  demoteNodeTypes _ = []
+
+b :: (Bool :: *)
+b = True
diff --git a/data/examples/declaration/type/misc-kind-signatures.hs b/data/examples/declaration/type/misc-kind-signatures.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/misc-kind-signatures.hs
@@ -0,0 +1,5 @@
+instance DemoteNodeTypes ('[] :: [NodeType]) where
+    demoteNodeTypes _ = []
+
+b :: (Bool :: *)
+b = True
diff --git a/data/examples/declaration/type/promotion-out.hs b/data/examples/declaration/type/promotion-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/promotion-out.hs
@@ -0,0 +1,19 @@
+type Foo = Cluster '[ 'NodeCore, 'NodeRelay', 'NodeEdge]
+
+data T = T' | T'T
+
+type S0 = ' T'
+
+type S1 = ' T'T
+
+type S2 = Proxy ('[ '[], '[]])
+
+type S4 = Proxy ('( 'Just, ' T'T))
+
+type S5 = Proxy ('[ 'Just, 'TT'T])
+
+type S6 = Proxy ('( '(), '()))
+
+type S7 = Proxy ('( 'a, 'b))
+
+type S8 = Proxy ('[Int, Bool])
diff --git a/data/examples/declaration/type/promotion.hs b/data/examples/declaration/type/promotion.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/promotion.hs
@@ -0,0 +1,15 @@
+type Foo = Cluster '[ 'NodeCore, 'NodeRelay', 'NodeEdge ]
+
+data T = T' | T'T
+
+type S0 = ' T'
+
+type S1 = ' T'T
+
+type S2 = Proxy ( '[ '[], '[] ])
+type S4 = Proxy ( '( 'Just, ' T'T))
+type S5 = Proxy ( '[ 'Just, ' TT'T])
+type S6 = Proxy ( '( '(), '() ))
+type S7 = Proxy ( '( 'a, 'b ))
+type S8 = Proxy ( '[ Int, Bool ])
+
diff --git a/data/examples/declaration/type/splice-out.hs b/data/examples/declaration/type/splice-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/splice-out.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+type Foo = $(bar [t|Int|])
diff --git a/data/examples/declaration/type/splice.hs b/data/examples/declaration/type/splice.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/splice.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+type   Foo  = $(         bar [t|Int|] )
diff --git a/data/examples/declaration/value/function/application-out.hs b/data/examples/declaration/value/function/application-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/application-out.hs
@@ -0,0 +1,17 @@
+foo =
+  f1
+    p1
+    p2
+    p3
+
+foo' =
+  f2
+    p1
+    p2
+    p3
+
+foo'' =
+  f3
+    p1
+    p2
+    p3
diff --git a/data/examples/declaration/value/function/application.hs b/data/examples/declaration/value/function/application.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/application.hs
@@ -0,0 +1,12 @@
+foo =
+  f1
+    p1
+    p2 p3
+
+foo' = f2 p1
+  p2
+  p3
+
+foo'' =
+  f3 p1 p2
+    p3
diff --git a/data/examples/declaration/value/function/arithmetic-sequences-out.hs b/data/examples/declaration/value/function/arithmetic-sequences-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arithmetic-sequences-out.hs
@@ -0,0 +1,24 @@
+foo = [0 ..]
+
+foo' = [0 .. 5]
+
+bar x =
+  [ 0
+    .. x
+  ]
+
+baz x =
+  [ 1,
+    3
+    .. x
+  ]
+
+barbaz x = [0, 1 ..]
+
+arst = [0 :: Int ..]
+
+brst = [0, 1 :: Int ..]
+
+crst = [0 :: Int .. 10]
+
+drst = [0, 1 :: Int .. 10]
diff --git a/data/examples/declaration/value/function/arithmetic-sequences.hs b/data/examples/declaration/value/function/arithmetic-sequences.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arithmetic-sequences.hs
@@ -0,0 +1,15 @@
+foo = [0..]
+foo' = [0..5]
+bar x = [
+    0..x
+  ]
+baz x = [
+    1,
+    3 ..
+    x
+  ]
+barbaz x = [ 0, 1.. ]
+arst = [0 :: Int ..]
+brst = [0, 1 :: Int ..]
+crst = [0 :: Int .. 10]
+drst = [0, 1 :: Int .. 10]
diff --git a/data/examples/declaration/value/function/arrow/expression-applications-out.hs b/data/examples/declaration/value/function/arrow/expression-applications-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/expression-applications-out.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE Arrows #-}
+
+foo x y = x -< y
+
+bar f x =
+  f x -< -- Hello
+    x -- World
+
+baz x y = x -<< y
diff --git a/data/examples/declaration/value/function/arrow/expression-applications.hs b/data/examples/declaration/value/function/arrow/expression-applications.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/expression-applications.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE Arrows #-}
+
+foo x y = x -< y
+
+bar f x
+    =  f x  -- Hello
+    -< x    -- World
+
+baz x y = x -<< y
diff --git a/data/examples/declaration/value/function/arrow/expression-forms-out.hs b/data/examples/declaration/value/function/arrow/expression-forms-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/expression-forms-out.hs
@@ -0,0 +1,14 @@
+{-# LANGUAGE Arrows #-}
+
+foo f g x y = (| test (f -< x) (g -< y) |)
+
+bar f g x y =
+  (|
+    test
+      ( f -<
+          x
+      )
+      ( g -<
+          y
+      )
+  |)
diff --git a/data/examples/declaration/value/function/arrow/expression-forms.hs b/data/examples/declaration/value/function/arrow/expression-forms.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/expression-forms.hs
@@ -0,0 +1,11 @@
+{-# LANGUAGE Arrows #-}
+
+foo f g x y = (| test (f -< x) (g -< y) |)
+
+bar f g x y = (|
+    test
+      (f
+       -< x)
+      (g
+       -< y)
+  |)
diff --git a/data/examples/declaration/value/function/arrow/proc-applications-out.hs b/data/examples/declaration/value/function/arrow/proc-applications-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-applications-out.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE Arrows #-}
+
+foo x = proc a -> a -< x
+
+bar f x =
+  proc
+    ( y,
+      z,
+      w
+      )
+  ->
+    f -< -- The value
+      ( x, -- Foo
+        w, -- Bar
+        z -- Baz
+      )
+
+baz x = proc a -> a -<< x
diff --git a/data/examples/declaration/value/function/arrow/proc-applications.hs b/data/examples/declaration/value/function/arrow/proc-applications.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-applications.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE Arrows #-}
+
+foo x = proc a -> a -< x
+
+bar f x =
+    proc (
+        y,
+        z,
+        w
+    ) -> f -- The value
+    -< (
+        x, -- Foo
+        w, -- Bar
+        z  -- Baz
+    )
+
+baz x = proc a -> a -<< x
diff --git a/data/examples/declaration/value/function/arrow/proc-cases-out.hs b/data/examples/declaration/value/function/arrow/proc-cases-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-cases-out.hs
@@ -0,0 +1,16 @@
+{-# LANGUAGE Arrows #-}
+
+foo f = proc a -> case a of Left b -> f -< b
+
+bar f g h j =
+  proc a -> case a of
+    Left
+      ( (a, b),
+        (c, d)
+        ) -> f (a <> c) -< b <> d
+    Right
+      (Left a) ->
+        h -< a
+    Right
+      (Right b) ->
+        j -< b
diff --git a/data/examples/declaration/value/function/arrow/proc-cases.hs b/data/examples/declaration/value/function/arrow/proc-cases.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-cases.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE Arrows #-}
+foo f =proc a -> case  a  of Left b -> f -<b
+
+bar f g h j
+  = proc a ->
+    case a of
+        Left (
+            (a, b),
+            (c, d)
+         ) -> f (a <> c) -< b <> d
+
+        Right
+          (Left a) ->
+            h -< a
+        Right
+          (Right b) ->
+            j -< b
diff --git a/data/examples/declaration/value/function/arrow/proc-do-complex-out.hs b/data/examples/declaration/value/function/arrow/proc-do-complex-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-do-complex-out.hs
@@ -0,0 +1,58 @@
+{-# LANGUAGE Arrows #-}
+
+foo
+  f
+  g
+  h
+  ma =
+    proc
+      ( (a, b),
+        (c, d),
+        (e, f)
+        )
+    -> do
+      -- Begin do
+      (x, y) <- -- GHC parser fails if layed out over multiple lines
+        f -- Call into f
+          ( a,
+            c -- Tuple together arguments
+          )
+          ( b,
+            d
+          ) -<
+          ( b + 1, -- Funnel into arrow
+            d * b
+          )
+      if x `mod` y == 0 -- Basic condition
+        then case e of -- Only left case is relevant
+          Left
+            ( z,
+              w
+              ) -> \u -> -- Procs can have lambdas
+              let v =
+                    u -- Actually never used
+                      ^ 2
+               in ( returnA -<
+                      -- Just do the calculation
+                      (x + y * z)
+                  )
+        else do
+          let u = x -- Let bindings bind expressions, not commands
+            -- Could pattern match directly on x
+          i <- case u of
+            0 -> (g . h -< u)
+            n ->
+              ( ( h . g -<
+                    y -- First actual use of y
+                )
+              )
+          returnA -< ()
+          -- Sometimes execute effects
+          if i > 0
+            then ma -< ()
+            else returnA -< ()
+          returnA -<
+            ( i
+                + x
+                * y -- Just do the calculation
+            )
diff --git a/data/examples/declaration/value/function/arrow/proc-do-complex.hs b/data/examples/declaration/value/function/arrow/proc-do-complex.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-do-complex.hs
@@ -0,0 +1,49 @@
+{-# LANGUAGE Arrows #-}
+foo
+  f
+  g
+  h
+  ma = proc (
+        (a, b),
+        (c, d),
+        (e, f)
+      ) ->
+    do -- Begin do
+        (x,y) -- GHC parser fails if layed out over multiple lines
+         <- f -- Call into f
+              (a,
+               c) -- Tuple together arguments
+              (b,
+               d)
+         -< (b + 1, -- Funnel into arrow
+             d * b)
+        if
+          x `mod` y == 0 -- Basic condition
+        then case e -- Only left case is relevant
+            of Left (z,
+                     w) -> \u -> -- Procs can have lambdas
+                let
+                    v
+                      = u -- Actually never used
+                        ^ 2
+                in
+                    (returnA
+                      -< -- Just do the calculation
+                     (x + y * z))
+        else do
+          let u = x -- Let bindings bind expressions, not commands
+          -- Could pattern match directly on x
+          i <- case u of
+            0 -> (g . h -< u)
+            n -> (
+                  (h . g
+                   -< y) -- First actual use of y
+                  )
+          returnA -< ()
+          -- Sometimes execute effects
+          if i > 0
+            then ma -< ()
+            else returnA -< ()
+          returnA -< (i +
+                      x *
+                      y) -- Just do the calculation
diff --git a/data/examples/declaration/value/function/arrow/proc-do-simple1-out.hs b/data/examples/declaration/value/function/arrow/proc-do-simple1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-do-simple1-out.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE Arrows #-}
+
+bar f = proc a -> do
+  b <- f -< a
+
+barbar f g = proc a -> do
+  b <- f -< a
+  returnA -< b
+
+barbaz f g = proc (a, b) -> do
+  c <- f -< a
+  d <- g -< b
+
+bazbar f = proc a -> do
+  a <-
+    f -<
+      a
diff --git a/data/examples/declaration/value/function/arrow/proc-do-simple1.hs b/data/examples/declaration/value/function/arrow/proc-do-simple1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-do-simple1.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE Arrows #-}
+
+bar f = proc a ->
+  do b <- f -< a
+
+barbar f g = proc a ->
+  do b <- f -< a
+     returnA -< b
+
+barbaz f g = proc (a, b) ->
+  do c <- f -< a
+     d <- g -< b
+
+bazbar f = proc a ->
+  do a
+       <-
+       f
+       -<
+       a
+
diff --git a/data/examples/declaration/value/function/arrow/proc-do-simple2-out.hs b/data/examples/declaration/value/function/arrow/proc-do-simple2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-do-simple2-out.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE Arrows #-}
+
+foo f = proc a -> do
+  f -< a
+
+bazbaz f g h = proc (a, b, c) -> do
+  x <-
+    f b -< a
+  y <-
+    g b -< b
+  z <-
+    h
+      x
+      y -<
+      ( a,
+        b,
+        c
+      )
+  returnA -<
+    (x, y, z)
diff --git a/data/examples/declaration/value/function/arrow/proc-do-simple2.hs b/data/examples/declaration/value/function/arrow/proc-do-simple2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-do-simple2.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE Arrows #-}
+foo f = proc a ->
+  do f -< a
+
+bazbaz f g h = proc (a, b, c) ->
+  do x
+       <- f b -< a
+     y <-
+       g b -< b
+     z <-
+       h
+         x
+         y
+       -< (
+           a,
+           b,
+           c
+       )
+     returnA -<
+       (x, y, z)
diff --git a/data/examples/declaration/value/function/arrow/proc-forms1-out.hs b/data/examples/declaration/value/function/arrow/proc-forms1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-forms1-out.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE Arrows #-}
+
+foo0 f g x y = proc _ -> (| f (g -< (x, y)) |)
+
+foo1 f g h x =
+  proc (y, z) ->
+    (|
+      test
+        ( h f
+            . h g -<
+            y x
+              . y z
+        )
+        ( h g
+            . h f -<
+            y z
+              . y x
+        )
+    |)
diff --git a/data/examples/declaration/value/function/arrow/proc-forms1.hs b/data/examples/declaration/value/function/arrow/proc-forms1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-forms1.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE Arrows #-}
+
+foo0 f g x y = proc _ -> (| f (g -< (x, y)) |)
+
+foo1 f g h x =
+  proc (y, z) -> (|
+    test ( h f
+             . h g
+             -<
+           y x
+             . y z
+         )
+         ( h g
+             . h f
+             -<
+           y z
+             . y x)
+  |)
+
diff --git a/data/examples/declaration/value/function/arrow/proc-forms2-out.hs b/data/examples/declaration/value/function/arrow/proc-forms2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-forms2-out.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE Arrows #-}
+
+bar0 f g h x =
+  proc (y, z) ->
+    (| test (h f . (h g) -< (y x) . y z) ((h g) . h f -< y z . (y x)) |)
+
+bar1 f g x y = proc _ -> f -< x &&& g -< y
+
+bar2 f g h x =
+  proc (y, z) ->
+    h f . (h g) -< (y x) . y z ||| (h g) . h f -< y z . (y x)
+
+bar3 f g h x =
+  proc (y, z) ->
+    (h f . h g) -<
+      (y x) . y z
+        ||| (h g . h f) -<
+        y z . (y x)
diff --git a/data/examples/declaration/value/function/arrow/proc-forms2.hs b/data/examples/declaration/value/function/arrow/proc-forms2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-forms2.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE Arrows #-}
+
+bar0 f g h x =
+  proc (y, z) ->
+    (|   test (h f.(h g)  -<  (y x).y z)((h g)  .  h f-<y z  .  (y x))   |)
+
+bar1 f g x y = proc _ -> f -< x&&&g -< y
+
+bar2 f g h x =
+  proc (y, z) ->
+    h f.(h g)  -<  (y x).y z ||| (h g)  .  h f-<y z  .  (y x)
+
+bar3 f g h x =
+  proc (y, z) ->
+    (h f.h g)
+      -<  (y x).y z
+  |||
+    (h g  .  h f)
+      -<y z  .  (y x)
diff --git a/data/examples/declaration/value/function/arrow/proc-ifs-out.hs b/data/examples/declaration/value/function/arrow/proc-ifs-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-ifs-out.hs
@@ -0,0 +1,13 @@
+{-# LANGUAGE Arrows #-}
+
+foo f = proc a -> if a then f -< 0 else f -< 1
+
+bar f g = proc a ->
+  if f a
+    then
+      f
+        . g -<
+        a
+    else
+      g -<
+        b
diff --git a/data/examples/declaration/value/function/arrow/proc-ifs.hs b/data/examples/declaration/value/function/arrow/proc-ifs.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-ifs.hs
@@ -0,0 +1,14 @@
+{-# LANGUAGE Arrows #-}
+
+foo f = proc a -> if a  then  f-<0  else  f-<1
+
+bar f g = proc a ->
+    if
+        f a
+    then
+          f
+        . g -< a
+    else
+        g
+        -<
+        b
diff --git a/data/examples/declaration/value/function/arrow/proc-lambdas-out.hs b/data/examples/declaration/value/function/arrow/proc-lambdas-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-lambdas-out.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE Arrows #-}
+
+foo = proc a -> \f b -> a -< f b -- Foo
+
+bar =
+  proc x -> \f g h ->
+    \() ->
+      \(Left (x, y)) -> -- Tuple value
+        f (g (h x)) -< y
diff --git a/data/examples/declaration/value/function/arrow/proc-lambdas.hs b/data/examples/declaration/value/function/arrow/proc-lambdas.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-lambdas.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE Arrows #-}
+
+foo = proc a->  \f b->a-<f b -- Foo
+
+bar =
+    proc x ->
+       \f g h ->
+       \() ->
+       \( Left (x,y )) -> -- Tuple value
+        f (g (h x)) -< y
diff --git a/data/examples/declaration/value/function/arrow/proc-lets-out.hs b/data/examples/declaration/value/function/arrow/proc-lets-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-lets-out.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE Arrows #-}
+
+foo f = proc a -> let b = a in f -< b
+
+bar f g = proc a ->
+  let h =
+        f
+          . g a
+      j =
+        g
+          . h
+   in id -< (h, j)
diff --git a/data/examples/declaration/value/function/arrow/proc-lets.hs b/data/examples/declaration/value/function/arrow/proc-lets.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-lets.hs
@@ -0,0 +1,14 @@
+{-# LANGUAGE Arrows #-}
+
+foo f = proc a -> let b = a in f -< b
+
+bar f g = proc a ->
+    let
+      h
+        = f
+        . g a
+      j = g
+          .
+          h
+    in
+      id -< (h, j)
diff --git a/data/examples/declaration/value/function/arrow/proc-parentheses-out.hs b/data/examples/declaration/value/function/arrow/proc-parentheses-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-parentheses-out.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE Arrows #-}
+
+foo f = proc a -> (f -< a)
+
+bar f g = proc a ->
+  ( ( (f)
+        ( g
+        )
+    ) -<
+      ( ( ( ( ( ( g
+                    a
+                )
+              )
+            )
+          )
+        )
+      )
+  )
diff --git a/data/examples/declaration/value/function/arrow/proc-parentheses.hs b/data/examples/declaration/value/function/arrow/proc-parentheses.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/proc-parentheses.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE Arrows #-}
+foo f = proc a -> ( f -< a )
+
+bar f g = proc a ->
+    ( ((f) (
+        g
+      ))
+    -< (((((
+        (g
+         a)
+        )))))
+    )
diff --git a/data/examples/declaration/value/function/arrow/recursive-procs-out.hs b/data/examples/declaration/value/function/arrow/recursive-procs-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/recursive-procs-out.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE Arrows #-}
+
+foo f g = proc (x, y) -> do
+  rec a <- f y -< x
+      b <-
+        g x -<
+          y
+  bar -<
+    ( a,
+      b
+    )
+  rec p <-
+        f
+          p -<
+          a
+  rec q <-
+        g
+          q -<
+          b
diff --git a/data/examples/declaration/value/function/arrow/recursive-procs.hs b/data/examples/declaration/value/function/arrow/recursive-procs.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/recursive-procs.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE Arrows #-}
+
+foo f g = proc (x, y) -> do
+  rec
+    a <- f y -< x
+    b
+        <-
+      g x
+        -<
+      y
+  bar -< (
+    a,
+    b
+   )
+  rec p <- f
+             p -< a
+  rec q <- g
+             q-< b
diff --git a/data/examples/declaration/value/function/backticks-lhs-out.hs b/data/examples/declaration/value/function/backticks-lhs-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/backticks-lhs-out.hs
@@ -0,0 +1,7 @@
+x `op1` (Just 0) = True
+op1 x (Just _) = False
+op1 x Nothing = undefined
+
+op2 1 y = False
+x `op2` y =
+  True
diff --git a/data/examples/declaration/value/function/backticks-lhs.hs b/data/examples/declaration/value/function/backticks-lhs.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/backticks-lhs.hs
@@ -0,0 +1,7 @@
+x `op1`            (Just 0) = True
+op1 x (Just _)    =      False
+op1 x       Nothing = undefined
+
+op2 1 y =   False
+x `op2` y =
+        True
diff --git a/data/examples/declaration/value/function/backticks-out.hs b/data/examples/declaration/value/function/backticks-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/backticks-out.hs
@@ -0,0 +1,1 @@
+foo x y = x `bar` y
diff --git a/data/examples/declaration/value/function/backticks.hs b/data/examples/declaration/value/function/backticks.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/backticks.hs
@@ -0,0 +1,1 @@
+foo x y = x `bar` y
diff --git a/data/examples/declaration/value/function/block-arguments-out.hs b/data/examples/declaration/value/function/block-arguments-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/block-arguments-out.hs
@@ -0,0 +1,29 @@
+f1 = foo do bar
+
+f2 = foo do
+  bar
+
+f3 = foo case True of
+  True -> bar
+  False -> baz
+
+f4 = foo let a = 3 in b
+
+f5 =
+  foo
+    let a = 3
+        b = a
+     in b
+
+f6 =
+  foo
+    if bar
+      then baz
+      else not baz
+
+f7 = foo \x -> y
+
+f8 = foo \x ->
+  y
+
+f9 = foo do { bar } baz
diff --git a/data/examples/declaration/value/function/block-arguments.hs b/data/examples/declaration/value/function/block-arguments.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/block-arguments.hs
@@ -0,0 +1,25 @@
+f1 = foo do bar
+
+f2 = foo do
+  bar
+
+f3 = foo case True of
+  True -> bar
+  False -> baz
+
+f4 = foo let a = 3 in b
+
+f5 = foo let a = 3
+             b = a
+          in b
+
+f6 = foo if bar
+         then baz
+         else not baz
+
+f7 = foo \x -> y
+
+f8 = foo \x ->
+  y
+
+f9 = foo do { bar } baz
diff --git a/data/examples/declaration/value/function/builtin-syntax-out.hs b/data/examples/declaration/value/function/builtin-syntax-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/builtin-syntax-out.hs
@@ -0,0 +1,1 @@
+x = return ()
diff --git a/data/examples/declaration/value/function/builtin-syntax.hs b/data/examples/declaration/value/function/builtin-syntax.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/builtin-syntax.hs
@@ -0,0 +1,1 @@
+x = return ()
diff --git a/data/examples/declaration/value/function/case-multi-line-guards-out.hs b/data/examples/declaration/value/function/case-multi-line-guards-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/case-multi-line-guards-out.hs
@@ -0,0 +1,16 @@
+withGuards :: Int -> Int
+withGuards x =
+  case x of
+    x
+      | x > 10 ->
+        foo
+          + bar
+    x | x > 5 -> 10
+    _ -> 20
+
+case x of
+  '-' | not isUrl -> case xs of
+    _ -> emitc '-'
+  '*' | not isUrl ->
+    case xs of
+      _ -> emitc '*'
diff --git a/data/examples/declaration/value/function/case-multi-line-guards.hs b/data/examples/declaration/value/function/case-multi-line-guards.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/case-multi-line-guards.hs
@@ -0,0 +1,15 @@
+withGuards :: Int -> Int
+withGuards x =
+  case x of
+    x | x > 10 ->
+      foo +
+        bar
+    x | x > 5 -> 10
+    _ -> 20
+
+case x of
+  '-' | not isUrl -> case xs of
+        _ -> emitc '-'
+  '*' | not isUrl ->
+        case xs of
+          _ -> emitc '*'
diff --git a/data/examples/declaration/value/function/case-multi-line-out.hs b/data/examples/declaration/value/function/case-multi-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/case-multi-line-out.hs
@@ -0,0 +1,27 @@
+foo :: Int -> Int
+foo x = case x of
+  5 -> 10
+  _ -> 12
+
+bar :: Int -> Int
+bar x =
+  case x of
+    5 ->
+      if x > 5
+        then 10
+        else 12
+    _ -> 12
+
+baz :: Int -> Int
+baz x = case x of
+  5 -> 10
+  _ -> 12
+
+quux :: Int -> Int
+quux x = case x of
+  x -> x
+
+funnyComment =
+  -- comment
+  case () of
+    () -> ()
diff --git a/data/examples/declaration/value/function/case-multi-line.hs b/data/examples/declaration/value/function/case-multi-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/case-multi-line.hs
@@ -0,0 +1,23 @@
+foo :: Int -> Int
+foo x = case x of
+  5 -> 10
+  _ -> 12
+
+bar :: Int -> Int
+bar x =
+  case x of
+    5 -> if x > 5
+           then 10 else 12
+    _ -> 12
+
+baz :: Int -> Int
+baz x = case x of 5 -> 10
+                  _ -> 12
+
+quux :: Int -> Int
+quux x = case x of
+  x -> x
+
+funnyComment = -- comment
+  case () of
+    () -> ()
diff --git a/data/examples/declaration/value/function/case-single-line-out.hs b/data/examples/declaration/value/function/case-single-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/case-single-line-out.hs
@@ -0,0 +1,6 @@
+foo :: Int -> Int
+foo x = case x of x -> x
+
+foo :: IO ()
+foo = case [1] of [_] -> "singleton"; _ -> "not singleton"
+foo = case [1] of { [] -> foo; _ -> bar } `finally` baz
diff --git a/data/examples/declaration/value/function/case-single-line.hs b/data/examples/declaration/value/function/case-single-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/case-single-line.hs
@@ -0,0 +1,6 @@
+foo :: Int -> Int
+foo x = case x of x -> x
+
+foo :: IO ()
+foo = case [1] of [_] -> "singleton"; _ -> "not singleton"
+foo = case [1] of { [] -> foo; _ -> bar } `finally` baz
diff --git a/data/examples/declaration/value/function/complex-list-out.hs b/data/examples/declaration/value/function/complex-list-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/complex-list-out.hs
@@ -0,0 +1,15 @@
+handleStuff =
+  handle
+    [ \ExceptionA ->
+        something,
+      \ExceptionB ->
+        somethingElse
+    ]
+
+handleStuff =
+  handle
+    [ foo
+        bar,
+      baz
+        qux
+    ]
diff --git a/data/examples/declaration/value/function/complex-list.hs b/data/examples/declaration/value/function/complex-list.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/complex-list.hs
@@ -0,0 +1,15 @@
+handleStuff =
+  handle
+    [ \ExceptionA ->
+        something
+    , \ExceptionB ->
+        somethingElse
+    ]
+
+handleStuff =
+  handle
+    [ foo
+        bar
+    , baz
+        qux
+    ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line1-out.hs b/data/examples/declaration/value/function/comprehension/transform-multi-line1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/comprehension/transform-multi-line1-out.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE TransformListComp #-}
+
+foo' xs ys =
+  [ ( x,
+      y
+    )
+    | x <- xs,
+      y <- ys,
+      then
+        -- First comment
+        reverse -- Second comment
+  ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line1.hs b/data/examples/declaration/value/function/comprehension/transform-multi-line1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/comprehension/transform-multi-line1.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE TransformListComp #-}
+
+foo' xs ys = [
+  (x,
+   y) |
+  x <- xs,
+  y <- ys,
+  then -- First comment
+    reverse -- Second comment
+  ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line2-out.hs b/data/examples/declaration/value/function/comprehension/transform-multi-line2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/comprehension/transform-multi-line2-out.hs
@@ -0,0 +1,16 @@
+{-# LANGUAGE TransformListComp #-}
+
+bar' xs ys =
+  [ ( x,
+      y
+    )
+    | x <- xs,
+      y <- ys,
+      then
+        -- First comment
+        sortWith
+      by
+        ( x
+            + y -- Second comment
+        )
+  ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line2.hs b/data/examples/declaration/value/function/comprehension/transform-multi-line2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/comprehension/transform-multi-line2.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE TransformListComp #-}
+
+bar' xs ys = [
+  (x,
+    y) |
+  x <- xs,
+  y <- ys,
+  then -- First comment
+    sortWith
+  by
+    (x
+      + y) -- Second comment
+  ]
+
+
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line3-out.hs b/data/examples/declaration/value/function/comprehension/transform-multi-line3-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/comprehension/transform-multi-line3-out.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE TransformListComp #-}
+
+baz' xs ys =
+  [ ( x,
+      y
+    )
+    | x <- xs,
+      y <- ys,
+      then group using
+        -- First comment
+        permutations -- Second comment
+  ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line3.hs b/data/examples/declaration/value/function/comprehension/transform-multi-line3.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/comprehension/transform-multi-line3.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE TransformListComp #-}
+
+baz' xs ys = [
+  (x,
+    y) |
+  x <- xs,
+  y <- ys,
+  then
+  group
+  using -- First comment
+    permutations -- Second comment
+  ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line4-out.hs b/data/examples/declaration/value/function/comprehension/transform-multi-line4-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/comprehension/transform-multi-line4-out.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE TransformListComp #-}
+
+quux' xs ys =
+  [ ( x,
+      y
+    )
+    | x <- xs,
+      y <- ys,
+      then group by
+        -- First comment
+        ( x
+            + y
+        )
+      using
+        -- Second comment
+        groupWith -- Third comment
+  ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-multi-line4.hs b/data/examples/declaration/value/function/comprehension/transform-multi-line4.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/comprehension/transform-multi-line4.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE TransformListComp #-}
+
+quux' xs ys = [
+  (x,
+    y) |
+  x <- xs,
+  y <- ys,
+  then
+  group
+  by -- First comment
+    (x
+      + y)
+  using -- Second comment
+    groupWith -- Third comment
+  ]
diff --git a/data/examples/declaration/value/function/comprehension/transform-single-line-out.hs b/data/examples/declaration/value/function/comprehension/transform-single-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/comprehension/transform-single-line-out.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE TransformListComp #-}
+
+foo xs ys = [(x, y) | x <- xs, y <- ys, then reverse]
+
+bar xs ys = [(x, y) | x <- xs, y <- ys, then sortWith by (x + y)]
+
+baz xs ys = [(x, y) | x <- xs, y <- ys, then group using permutations]
+
+quux xs ys = [(x, y) | x <- xs, y <- ys, then group by (x + y) using groupWith]
diff --git a/data/examples/declaration/value/function/comprehension/transform-single-line.hs b/data/examples/declaration/value/function/comprehension/transform-single-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/comprehension/transform-single-line.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE TransformListComp #-}
+
+foo xs ys = [(x, y) | x <- xs, y <- ys, then reverse]
+
+bar xs ys = [(x, y) | x <- xs, y <- ys, then sortWith by (x + y)]
+
+baz xs ys = [(x, y) | x <- xs, y <- ys, then group using permutations]
+
+quux xs ys = [(x, y) | x <- xs, y <- ys, then group by (x + y) using groupWith]
diff --git a/data/examples/declaration/value/function/do-single-multi-out.hs b/data/examples/declaration/value/function/do-single-multi-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do-single-multi-out.hs
@@ -0,0 +1,4 @@
+foo = do
+  ( bar
+      baz
+    )
diff --git a/data/examples/declaration/value/function/do-single-multi.hs b/data/examples/declaration/value/function/do-single-multi.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do-single-multi.hs
@@ -0,0 +1,2 @@
+foo = do (bar
+          baz)
diff --git a/data/examples/declaration/value/function/do-where-out.hs b/data/examples/declaration/value/function/do-where-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do-where-out.hs
@@ -0,0 +1,5 @@
+f :: Maybe Int
+f = do
+  return c
+  where
+    c = 0
diff --git a/data/examples/declaration/value/function/do-where.hs b/data/examples/declaration/value/function/do-where.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do-where.hs
@@ -0,0 +1,5 @@
+f :: Maybe Int
+f = do
+  return c
+  where
+    c = 0
diff --git a/data/examples/declaration/value/function/do/applications-and-parens-out.hs b/data/examples/declaration/value/function/do/applications-and-parens-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/applications-and-parens-out.hs
@@ -0,0 +1,9 @@
+warningFor var place = do
+  guard $ isVariableName var
+  guard . not $ isInArray var place || isGuarded place
+  ( if includeGlobals || isLocal var
+      then warningForLocals
+      else warningForGlobals
+    )
+    var
+    place
diff --git a/data/examples/declaration/value/function/do/applications-and-parens.hs b/data/examples/declaration/value/function/do/applications-and-parens.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/applications-and-parens.hs
@@ -0,0 +1,6 @@
+warningFor var place = do
+    guard $ isVariableName var
+    guard . not $ isInArray var place || isGuarded place
+    (if includeGlobals || isLocal var
+     then warningForLocals
+     else warningForGlobals) var place
diff --git a/data/examples/declaration/value/function/do/blocks-out.hs b/data/examples/declaration/value/function/do/blocks-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/blocks-out.hs
@@ -0,0 +1,18 @@
+foo = do bar
+
+foo = do bar; baz
+
+foo = do
+  bar
+  baz
+
+foo = do do { foo; bar }; baz
+
+readInClause = do
+  do
+    lookAhead g_Do
+    parseNote ErrorC 1063 "You need a line feed or semicolon before the 'do'."
+    <|> do
+      optional g_Semi
+      void allspacing
+  return things
diff --git a/data/examples/declaration/value/function/do/blocks.hs b/data/examples/declaration/value/function/do/blocks.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/blocks.hs
@@ -0,0 +1,17 @@
+foo = do bar
+foo = do { bar; baz }
+foo = do { bar
+         ; baz
+         }
+foo = do { do {foo; bar}; baz }
+
+readInClause = do
+    do {
+        lookAhead g_Do;
+        parseNote ErrorC 1063 "You need a line feed or semicolon before the 'do'.";
+    } <|> do {
+        optional g_Semi;
+        void allspacing;
+    }
+
+    return things
diff --git a/data/examples/declaration/value/function/do/expr-out.hs b/data/examples/declaration/value/function/do/expr-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/expr-out.hs
@@ -0,0 +1,10 @@
+quux = something $ do
+  foo
+  case x of
+    1 -> 10
+    2 -> 20
+  bar
+  if something
+    then x
+    else y
+  baz
diff --git a/data/examples/declaration/value/function/do/expr.hs b/data/examples/declaration/value/function/do/expr.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/expr.hs
@@ -0,0 +1,10 @@
+quux = something $ do
+  foo
+  case x of
+    1 -> 10
+    2 -> 20
+  bar
+  if something
+  then x
+  else y
+  baz
diff --git a/data/examples/declaration/value/function/do/hang-rhs-arrow-out.hs b/data/examples/declaration/value/function/do/hang-rhs-arrow-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/hang-rhs-arrow-out.hs
@@ -0,0 +1,9 @@
+foo = do
+  something <- case bar of
+    Foo -> return 1
+    Bar -> return 2
+  somethingElse <-
+    case boom of
+      Foo -> return 1
+      Bar -> return 2
+  quux something somethingElse
diff --git a/data/examples/declaration/value/function/do/hang-rhs-arrow.hs b/data/examples/declaration/value/function/do/hang-rhs-arrow.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/hang-rhs-arrow.hs
@@ -0,0 +1,9 @@
+foo = do
+  something <- case bar of
+    Foo -> return 1
+    Bar -> return 2
+  somethingElse <-
+    case boom of
+      Foo -> return 1
+      Bar -> return 2
+  quux something somethingElse
diff --git a/data/examples/declaration/value/function/do/let-out.hs b/data/examples/declaration/value/function/do/let-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/let-out.hs
@@ -0,0 +1,18 @@
+main = do
+  a <- bar
+  let a = b; c = d
+  baz d
+  let e = f
+      g = h
+  return c
+
+-- single line let-where
+samples n f = do
+  gen <- newQCGen
+  let rands g = g1 : rands g2 where (g1, g2) = split g
+  return $ rands gen
+
+trickyLet = do
+  foo
+  let x = 5
+   in bar x
diff --git a/data/examples/declaration/value/function/do/let.hs b/data/examples/declaration/value/function/do/let.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/let.hs
@@ -0,0 +1,18 @@
+main = do
+  a <- bar
+  let a = b; c = d
+  baz d
+  let e = f
+      g = h
+  return c
+
+-- single line let-where
+samples n f = do
+    gen <- newQCGen
+    let rands g = g1 : rands g2 where (g1, g2) = split g
+    return $ rands gen
+
+trickyLet = do
+  foo
+  let x = 5
+   in bar x
diff --git a/data/examples/declaration/value/function/do/operator-and-parens-out.hs b/data/examples/declaration/value/function/do/operator-and-parens-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/operator-and-parens-out.hs
@@ -0,0 +1,7 @@
+scientifically :: (Scientific -> a) -> Parser a
+scientifically h = do
+  something
+  ( I.satisfy (\w -> w == 'e' || w == 'E')
+      *> fmap (h . Sci.scientific signedCoeff . (e +)) (signed decimal)
+    )
+    <|> return (h $ Sci.scientific signedCoeff e)
diff --git a/data/examples/declaration/value/function/do/operator-and-parens.hs b/data/examples/declaration/value/function/do/operator-and-parens.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/operator-and-parens.hs
@@ -0,0 +1,7 @@
+scientifically :: (Scientific -> a) -> Parser a
+scientifically h = do
+  something
+  ( I.satisfy (\w -> w == 'e' || w == 'E')
+      *> fmap (h . Sci.scientific signedCoeff . (e +)) (signed decimal)
+    )
+    <|> return (h $ Sci.scientific signedCoeff e)
diff --git a/data/examples/declaration/value/function/do/recursive-do-mdo-out.hs b/data/examples/declaration/value/function/do/recursive-do-mdo-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/recursive-do-mdo-out.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE RecursiveDo #-}
+
+baz =
+  mdo
+    bar a
+    a <- foo
+    b <-
+      bar
+        1
+        2
+        3
+    return (a + b)
diff --git a/data/examples/declaration/value/function/do/recursive-do-mdo.hs b/data/examples/declaration/value/function/do/recursive-do-mdo.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/recursive-do-mdo.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE RecursiveDo #-}
+
+baz =
+  mdo bar a
+      a <- foo
+      b <- bar
+        1 2 3
+      return (a + b)
diff --git a/data/examples/declaration/value/function/do/recursive-do-rec-out.hs b/data/examples/declaration/value/function/do/recursive-do-rec-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/recursive-do-rec-out.hs
@@ -0,0 +1,14 @@
+{-# LANGUAGE RecursiveDo #-}
+
+foo = do
+  rec a <- b + 5
+      let d = c
+      b <- a * 5
+      something
+      c <- a + b
+  print c
+  rec something $ do
+        x <- a
+        print x
+        y <- c
+        print y
diff --git a/data/examples/declaration/value/function/do/recursive-do-rec.hs b/data/examples/declaration/value/function/do/recursive-do-rec.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/do/recursive-do-rec.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE RecursiveDo #-}
+
+foo = do
+  rec
+    a <- b + 5
+
+    let d = c
+
+    b <- a * 5
+
+    something
+
+    c <- a + b
+  print c
+  rec something $ do
+          x <- a
+          print x
+
+          y <- c
+          print y
diff --git a/data/examples/declaration/value/function/equality-constraints-out.hs b/data/examples/declaration/value/function/equality-constraints-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/equality-constraints-out.hs
@@ -0,0 +1,2 @@
+foo :: (a ~ b) => a -> b -> Int
+foo = undefined
diff --git a/data/examples/declaration/value/function/equality-constraints.hs b/data/examples/declaration/value/function/equality-constraints.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/equality-constraints.hs
@@ -0,0 +1,2 @@
+foo :: (a ~ b) => a -> b -> Int
+foo = undefined
diff --git a/data/examples/declaration/value/function/explicit-type-out.hs b/data/examples/declaration/value/function/explicit-type-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/explicit-type-out.hs
@@ -0,0 +1,5 @@
+foo = 5 :: Int
+
+bar =
+  5 ::
+    Int
diff --git a/data/examples/declaration/value/function/explicit-type.hs b/data/examples/declaration/value/function/explicit-type.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/explicit-type.hs
@@ -0,0 +1,4 @@
+foo = 5 :: Int
+
+bar = 5
+  :: Int
diff --git a/data/examples/declaration/value/function/fancy-forall-0-out.hs b/data/examples/declaration/value/function/fancy-forall-0-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/fancy-forall-0-out.hs
@@ -0,0 +1,10 @@
+wrapError ::
+  forall outertag innertag t outer inner m a.
+  ( forall x. Coercible (t m x) (m x),
+    forall m'.
+    HasCatch outertag outer m' =>
+    HasCatch innertag inner (t m'),
+    HasCatch outertag outer m
+  ) =>
+  (forall m'. HasCatch innertag inner m' => m' a) ->
+  m a
diff --git a/data/examples/declaration/value/function/fancy-forall-0.hs b/data/examples/declaration/value/function/fancy-forall-0.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/fancy-forall-0.hs
@@ -0,0 +1,6 @@
+wrapError :: forall outertag innertag t outer inner m a.
+  ( forall x. Coercible (t m x) (m x)
+  , forall m'. HasCatch outertag outer m'
+    => HasCatch innertag inner (t m')
+  , HasCatch outertag outer m )
+  => (forall m'. HasCatch innertag inner m' => m' a) -> m a
diff --git a/data/examples/declaration/value/function/fancy-forall-1-out.hs b/data/examples/declaration/value/function/fancy-forall-1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/fancy-forall-1-out.hs
@@ -0,0 +1,10 @@
+magnify ::
+  forall outertag innertag t outer inner m a.
+  ( forall x. Coercible (t m x) (m x),
+    forall m'.
+    HasReader outertag outer m' =>
+    HasReader innertag inner (t m'),
+    HasReader outertag outer m
+  ) =>
+  (forall m'. HasReader innertag inner m' => m' a) ->
+  m a
diff --git a/data/examples/declaration/value/function/fancy-forall-1.hs b/data/examples/declaration/value/function/fancy-forall-1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/fancy-forall-1.hs
@@ -0,0 +1,6 @@
+magnify :: forall outertag innertag t outer inner m a.
+  ( forall x. Coercible (t m x) (m x)
+  , forall m'. HasReader outertag outer m'
+    => HasReader innertag inner (t m')
+  , HasReader outertag outer m )
+  => (forall m'. HasReader innertag inner m' => m' a) -> m a
diff --git a/data/examples/declaration/value/function/guards-out.hs b/data/examples/declaration/value/function/guards-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/guards-out.hs
@@ -0,0 +1,12 @@
+baz :: Int -> Int
+baz x | x < 0 = x
+baz x | otherwise = x
+
+multi_baz :: Int -> Int
+multi_baz x | x < 42 = x
+multi_baz x | x < 0 = x
+multi_baz x | otherwise = x
+
+quux :: Int -> Int
+quux x | x < 0 = x
+quux x = x
diff --git a/data/examples/declaration/value/function/guards.hs b/data/examples/declaration/value/function/guards.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/guards.hs
@@ -0,0 +1,12 @@
+baz :: Int -> Int
+baz x | x < 0 = x
+baz x | otherwise = x
+
+multi_baz :: Int -> Int
+multi_baz x | x < 42 = x
+multi_baz x | x < 0 = x
+multi_baz x | otherwise = x
+
+quux :: Int -> Int
+quux x | x < 0 = x
+quux x = x
diff --git a/data/examples/declaration/value/function/if-multi-line-out.hs b/data/examples/declaration/value/function/if-multi-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/if-multi-line-out.hs
@@ -0,0 +1,23 @@
+foo :: Int -> Int
+foo x =
+  if x > 5
+    then 10
+    else 12
+
+bar :: Int -> Int
+bar x =
+  if x > 5
+    then
+      foo x
+        + 100
+    else case x of
+      1 -> 10
+      _ -> 20
+
+baz :: Int -> Bar
+baz x =
+  if x > 5
+    then \case
+      Foo -> bar
+    else do
+      undefined
diff --git a/data/examples/declaration/value/function/if-multi-line.hs b/data/examples/declaration/value/function/if-multi-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/if-multi-line.hs
@@ -0,0 +1,22 @@
+foo :: Int -> Int
+foo x = if x > 5 then 10
+  else 12
+
+bar :: Int -> Int
+bar x =
+  if x > 5
+  then foo x
+         + 100
+  else case x of
+         1 -> 10
+         _ -> 20
+
+baz :: Int -> Bar
+baz x =
+  if x > 5
+  then
+    \case
+      Foo -> bar
+  else
+    do
+      undefined
diff --git a/data/examples/declaration/value/function/if-single-line-out.hs b/data/examples/declaration/value/function/if-single-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/if-single-line-out.hs
@@ -0,0 +1,6 @@
+foo :: Int -> Int
+foo x = if x > 5 then 10 else 12
+
+bar :: Int -> Int
+bar x =
+  if x > 5 then 10 else 12
diff --git a/data/examples/declaration/value/function/if-single-line.hs b/data/examples/declaration/value/function/if-single-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/if-single-line.hs
@@ -0,0 +1,6 @@
+foo :: Int -> Int
+foo x = if x > 5 then 10 else 12
+
+bar :: Int -> Int
+bar x =
+  if x > 5 then 10 else 12
diff --git a/data/examples/declaration/value/function/implicit-params-out.hs b/data/examples/declaration/value/function/implicit-params-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/implicit-params-out.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE ImplicitParams #-}
+
+sortBy :: (a -> a -> Bool) -> [a] -> [a]
+
+sort :: (?cmp :: a -> a -> Bool) => [a] -> [a]
+sort = sortBy ?cmp
+
+sort' ::
+  ( ?cmp ::
+      a -> a -> Bool,
+    ?foo :: Int
+  ) =>
+  [a] ->
+  [a]
+sort' = sort
diff --git a/data/examples/declaration/value/function/implicit-params.hs b/data/examples/declaration/value/function/implicit-params.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/implicit-params.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE ImplicitParams #-}
+sortBy :: (a -> a -> Bool) -> [a] -> [a]
+
+sort   :: (?cmp :: a -> a -> Bool) => [a] -> [a]
+sort    = sortBy ?cmp
+
+sort' ::  (?cmp
+             :: a -> a -> Bool
+          ,?foo :: Int) => [a] -> [a]
+sort' = sort
diff --git a/data/examples/declaration/value/function/infix/applicative-out.hs b/data/examples/declaration/value/function/infix/applicative-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/applicative-out.hs
@@ -0,0 +1,4 @@
+f =
+  Foo <$> bar
+    <*> baz
+    <*> baz'
diff --git a/data/examples/declaration/value/function/infix/applicative.hs b/data/examples/declaration/value/function/infix/applicative.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/applicative.hs
@@ -0,0 +1,4 @@
+f =
+  Foo <$> bar
+      <*> baz
+      <*> baz'
diff --git a/data/examples/declaration/value/function/infix/comments-out.hs b/data/examples/declaration/value/function/infix/comments-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/comments-out.hs
@@ -0,0 +1,8 @@
+main =
+  bar $ -- bar
+    baz -- baz
+
+bar $
+  {- foo
+   -}
+  bar
diff --git a/data/examples/declaration/value/function/infix/comments.hs b/data/examples/declaration/value/function/infix/comments.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/comments.hs
@@ -0,0 +1,8 @@
+main =
+  bar $ -- bar
+    baz -- baz
+
+bar $
+  {- foo
+   -}
+  bar
diff --git a/data/examples/declaration/value/function/infix/do-out.hs b/data/examples/declaration/value/function/infix/do-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/do-out.hs
@@ -0,0 +1,13 @@
+main =
+  do stuff
+    `finally` do
+      recover
+
+main = do stuff `finally` recover
+
+main = do { stuff } `finally` recover
+
+foo =
+  do
+    1
+    + 2
diff --git a/data/examples/declaration/value/function/infix/do.hs b/data/examples/declaration/value/function/infix/do.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/do.hs
@@ -0,0 +1,13 @@
+main =
+  do stuff
+   `finally` do
+     recover
+
+main = do stuff `finally` recover
+
+main = do { stuff  } `finally` recover
+
+foo = do
+    1
+    +
+    2
diff --git a/data/examples/declaration/value/function/infix/dollar-chains-out.hs b/data/examples/declaration/value/function/infix/dollar-chains-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/dollar-chains-out.hs
@@ -0,0 +1,18 @@
+module Main where
+
+foo =
+  fmap escapeLeadingDollar
+    . dropPaddingSpace
+    . dropWhileEnd T.null
+    . fmap (T.stripEnd . T.pack)
+    . lines
+    $ unpackHDS docStr
+
+foo =
+  when (GHC.xopt Cpp dynFlags && not cfgTolerateCpp) $
+    throwIO (OrmoluCppEnabled path)
+
+foo =
+  bar
+    $ baz
+    $ quux
diff --git a/data/examples/declaration/value/function/infix/dollar-chains.hs b/data/examples/declaration/value/function/infix/dollar-chains.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/dollar-chains.hs
@@ -0,0 +1,18 @@
+module Main where
+
+foo =
+  fmap escapeLeadingDollar
+    . dropPaddingSpace
+    . dropWhileEnd T.null
+    . fmap (T.stripEnd . T.pack)
+    . lines
+    $ unpackHDS docStr
+
+foo =
+  when (GHC.xopt Cpp dynFlags && not cfgTolerateCpp) $
+    throwIO (OrmoluCppEnabled path)
+
+foo =
+  bar
+    $ baz
+    $ quux
diff --git a/data/examples/declaration/value/function/infix/hanging-out.hs b/data/examples/declaration/value/function/infix/hanging-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/hanging-out.hs
@@ -0,0 +1,22 @@
+f = unFoo . foo bar baz 3 $ do
+  act
+  ret
+
+g = unFoo
+  . foo
+    bar
+    baz
+    3
+  $ do
+    act
+    ret
+
+update =
+  do
+    foobar
+    `catch` \case
+      a -> a
+
+foo = bar
+  ++ case foo of
+    a -> a
diff --git a/data/examples/declaration/value/function/infix/hanging.hs b/data/examples/declaration/value/function/infix/hanging.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/hanging.hs
@@ -0,0 +1,19 @@
+f = unFoo . foo bar baz 3 $  do
+  act
+  ret
+
+g = unFoo . foo
+      bar
+      baz 3 $  do
+  act
+  ret
+
+update =
+    do
+      foobar
+    `catch` \case
+      a -> a
+
+foo = bar ++
+    case foo of
+      a -> a
diff --git a/data/examples/declaration/value/function/infix/lenses-out.hs b/data/examples/declaration/value/function/infix/lenses-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/lenses-out.hs
@@ -0,0 +1,20 @@
+lenses =
+  Just $ M.fromList $
+    "type" .= ("user.connection" :: Text)
+      # "connection" .= uc
+      # "user" .= case name of
+        Just n -> Just $ object ["name" .= n]
+        Nothing -> Nothing
+      # []
+
+foo =
+  a
+    & b .~ 2
+    & c .~ 3
+
+wreq =
+  let opts =
+        defaults & auth ?~ awsAuth AWSv4 "key" "secret"
+          & header "Accept" .~ ["application/json"]
+          & header "Runscope-Bucket-Auth" .~ ["1example-1111-4yyyy-zzzz-xxxxxxxx"]
+   in getWith opts
diff --git a/data/examples/declaration/value/function/infix/lenses.hs b/data/examples/declaration/value/function/infix/lenses.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/lenses.hs
@@ -0,0 +1,16 @@
+lenses = Just $ M.fromList
+  $ "type"       .= ("user.connection" :: Text)
+  # "connection" .= uc
+  # "user"       .= case name of
+      Just  n -> Just $ object ["name" .= n]
+      Nothing -> Nothing
+  # []
+
+foo = a
+  & b .~ 2 & c .~ 3
+
+wreq =
+  let opts = defaults & auth ?~ awsAuth AWSv4 "key" "secret"
+                          & header "Accept" .~ ["application/json"]
+                          & header "Runscope-Bucket-Auth" .~ ["1example-1111-4yyyy-zzzz-xxxxxxxx"]
+  in  getWith opts
diff --git a/data/examples/declaration/value/function/infix/simple-out.hs b/data/examples/declaration/value/function/infix/simple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/simple-out.hs
@@ -0,0 +1,12 @@
+(*) :: Int -> Int -> Int
+x * y = z
+
+foo :: Int -> Int -> Int
+x `foo` y = z
+
+bar :: Int -> Int -> Int -> Int
+(x `bar` y) z = z
+
+multiline :: Int -> Int -> Int
+x
+  `multiline` y = z
diff --git a/data/examples/declaration/value/function/infix/simple.hs b/data/examples/declaration/value/function/infix/simple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/simple.hs
@@ -0,0 +1,12 @@
+(*) :: Int -> Int -> Int
+x * y = z
+
+foo :: Int -> Int -> Int
+x `foo` y = z
+
+bar :: Int -> Int -> Int -> Int
+(x `bar` y) z = z
+
+multiline :: Int -> Int -> Int
+x `multiline`
+  y = z
diff --git a/data/examples/declaration/value/function/infix/unicode-out.hs b/data/examples/declaration/value/function/infix/unicode-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/unicode-out.hs
@@ -0,0 +1,3 @@
+main = print ('a' → 'a')
+  where
+    (→) = (,)
diff --git a/data/examples/declaration/value/function/infix/unicode.hs b/data/examples/declaration/value/function/infix/unicode.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/infix/unicode.hs
@@ -0,0 +1,3 @@
+main = print ('a' → 'a')
+  where
+    (→) = (,)
diff --git a/data/examples/declaration/value/function/lambda-case-out.hs b/data/examples/declaration/value/function/lambda-case-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/lambda-case-out.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE LambdaCase #-}
+
+foo = bar (\case JKey {} -> True; _ -> False)
+
+foo :: Int -> Int
+foo = \case
+  5 -> 10
+  i | i > 5 -> 11
+  _ -> 12
diff --git a/data/examples/declaration/value/function/lambda-case.hs b/data/examples/declaration/value/function/lambda-case.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/lambda-case.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE LambdaCase #-}
+
+foo = bar (\case JKey{} -> True; _ -> False)
+
+foo :: Int -> Int
+foo = \case
+  5 -> 10
+  i  | i > 5 -> 11
+  _ -> 12
diff --git a/data/examples/declaration/value/function/lambda-multi-line1-out.hs b/data/examples/declaration/value/function/lambda-multi-line1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/lambda-multi-line1-out.hs
@@ -0,0 +1,15 @@
+foo :: a -> a -> a
+foo x = \y ->
+  x
+
+bar :: Int -> Int -> Int
+bar x = \y ->
+  if x > y
+    then 10
+    else 12
+
+foo =
+  prop "is inverse to closure" $
+    \(f :: StaticPtr (Int -> Int))
+     (x :: Int) ->
+        (unclosure . closure) f x == deRefStaticPtr f x
diff --git a/data/examples/declaration/value/function/lambda-multi-line1.hs b/data/examples/declaration/value/function/lambda-multi-line1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/lambda-multi-line1.hs
@@ -0,0 +1,14 @@
+foo :: a -> a -> a
+foo x = \y ->
+  x
+
+bar :: Int -> Int -> Int
+bar x = \y ->
+  if x > y
+    then 10
+    else 12
+
+foo =
+  prop "is inverse to closure" $ \(f :: StaticPtr (Int -> Int))
+  (x :: Int) ->
+      (unclosure . closure) f x == deRefStaticPtr f x
diff --git a/data/examples/declaration/value/function/lambda-multi-line2-out.hs b/data/examples/declaration/value/function/lambda-multi-line2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/lambda-multi-line2-out.hs
@@ -0,0 +1,12 @@
+tricky0 =
+  flip all (zip ws gs) $ \(wt, gt) ->
+    canUnify poly_given_ok wt gt || go False wt gt
+
+tricky1 =
+  flip all (zip ws gs) $
+    \(wt, gt) -> canUnify poly_given_ok wt gt || go False wt gt
+
+tricky2 =
+  flip all (zip ws gs) $
+    \(wt, gt) ->
+      canUnify poly_given_ok wt gt || go False wt gt
diff --git a/data/examples/declaration/value/function/lambda-multi-line2.hs b/data/examples/declaration/value/function/lambda-multi-line2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/lambda-multi-line2.hs
@@ -0,0 +1,12 @@
+tricky0 =
+  flip all (zip ws gs) $ \(wt, gt) ->
+    canUnify poly_given_ok wt gt || go False wt gt
+
+tricky1 =
+  flip all (zip ws gs) $
+  \(wt, gt) -> canUnify poly_given_ok wt gt || go False wt gt
+
+tricky2 =
+  flip all (zip ws gs) $
+  \(wt, gt) ->
+    canUnify poly_given_ok wt gt || go False wt gt
diff --git a/data/examples/declaration/value/function/lambda-single-line-out.hs b/data/examples/declaration/value/function/lambda-single-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/lambda-single-line-out.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE BangPatterns #-}
+
+foo :: a -> a -> a
+foo x = \y -> x
+
+bar :: a -> a -> a
+bar x =
+  \y -> x
+
+baz :: a -> a -> a
+baz = \ ~x ~y -> x
+
+zag :: a -> a -> a
+zag = \ !x !y -> x
+
+spl :: a -> a
+spl = \ $([p|x|]) -> x
diff --git a/data/examples/declaration/value/function/lambda-single-line.hs b/data/examples/declaration/value/function/lambda-single-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/lambda-single-line.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE BangPatterns #-}
+
+foo :: a -> a -> a
+foo x = \y -> x
+
+bar :: a -> a -> a
+bar x =
+  \y -> x
+
+baz :: a -> a -> a
+baz = \ ~x  ~y -> x
+
+zag :: a -> a -> a
+zag = \ !x  !y -> x
+
+spl :: a -> a
+spl = \ $([p|x|]) -> x
diff --git a/data/examples/declaration/value/function/let-multi-line-out.hs b/data/examples/declaration/value/function/let-multi-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/let-multi-line-out.hs
@@ -0,0 +1,28 @@
+foo :: Int -> Int
+foo x =
+  let z = y
+      y = x
+   in z + 100
+
+bar :: Int -> Int
+bar x =
+  let z = y
+      y = x
+   in z
+        + 100
+
+inlineComment :: Int -> Int
+inlineComment =
+  let {- join -} go = case () of
+                   () -> undefined
+   in go
+
+implicitParams :: HasCallStack => Int
+implicitParams =
+  let ?cs = ?callstack
+   in foo cs
+
+sitting =
+  foo $
+    let x = 20
+     in x
diff --git a/data/examples/declaration/value/function/let-multi-line.hs b/data/examples/declaration/value/function/let-multi-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/let-multi-line.hs
@@ -0,0 +1,27 @@
+foo :: Int -> Int
+foo x =
+  let z = y
+      y = x
+  in z + 100
+
+bar :: Int -> Int
+bar x =
+  let z = y
+      y = x
+  in z
+      + 100
+
+inlineComment :: Int -> Int
+inlineComment =
+  let {- join -} go = case () of
+                   () -> undefined
+  in go
+
+implicitParams :: HasCallStack => Int
+implicitParams =
+  let ?cs = ?callstack
+  in  foo cs
+
+sitting =
+  foo $ let x = 20
+         in x
diff --git a/data/examples/declaration/value/function/let-nested-out.hs b/data/examples/declaration/value/function/let-nested-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/let-nested-out.hs
@@ -0,0 +1,3 @@
+_ = _
+  where
+    _ = [_ | let _ = _]
diff --git a/data/examples/declaration/value/function/let-nested.hs b/data/examples/declaration/value/function/let-nested.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/let-nested.hs
@@ -0,0 +1,3 @@
+_ = _
+  where
+    _ = [_ | let _ = _]
diff --git a/data/examples/declaration/value/function/let-single-line-out.hs b/data/examples/declaration/value/function/let-single-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/let-single-line-out.hs
@@ -0,0 +1,11 @@
+foo :: a -> a
+foo x = let x = x in x
+foo x = let x = z where z = 2 in x
+foo x = let x = z where { z = 2 }; a = 3 in x
+foo x = let g :: Int -> Int; g = id in ()
+
+let a = b; c = do { foo; bar }; d = baz in b
+
+let a = case True of { True -> foo; False -> bar }; b = foo a in b
+
+foo x = let ?g = id; ?f = g in x
diff --git a/data/examples/declaration/value/function/let-single-line.hs b/data/examples/declaration/value/function/let-single-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/let-single-line.hs
@@ -0,0 +1,8 @@
+foo :: a -> a
+foo x = let x = x in x
+foo x = let x = z where z = 2 in x
+foo x = let x = z where { z = 2; }; a = 3 in x
+foo x = let {g :: Int -> Int; g = id} in ()
+let a = b; c = do { foo; bar }; d = baz in b
+let a = case True of { True -> foo; False -> bar }; b = foo a in b
+foo x = let {?g = id; ?f = g} in x
diff --git a/data/examples/declaration/value/function/list-comprehensions-out.hs b/data/examples/declaration/value/function/list-comprehensions-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/list-comprehensions-out.hs
@@ -0,0 +1,24 @@
+foo x = [a | a <- x]
+
+bar x y = [(a, b) | a <- x, even a, b <- y, a != b]
+
+barbaz x y z w =
+  [ (a, b, c, d) -- Foo
+    | a <-
+        x, -- Bar
+      b <- y, -- Baz
+      any even [a, b],
+      c <-
+        z
+          * z ^ 2, -- Bar baz
+      d <-
+        w
+          + w, -- Baz bar
+      all
+        even
+        [ a,
+          b,
+          c,
+          d
+        ]
+  ]
diff --git a/data/examples/declaration/value/function/list-comprehensions.hs b/data/examples/declaration/value/function/list-comprehensions.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/list-comprehensions.hs
@@ -0,0 +1,22 @@
+foo x =  [a |a<-x]
+
+bar x y = [  (a, b)  |  a<-x, even a  , b<-y, a != b  ]
+
+barbaz x y z w = [
+    (a, b, c, d) | -- Foo
+    a <-
+      x, -- Bar
+    b<-y,  -- Baz
+    any even [a, b],
+    c <- z *
+         z ^ 2,     -- Bar baz
+    d <-
+    w
+    +
+    w, -- Baz bar
+     all
+      even [
+        a, b,
+        c, d
+      ]
+  ]
diff --git a/data/examples/declaration/value/function/multi-way-if-out.hs b/data/examples/declaration/value/function/multi-way-if-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/multi-way-if-out.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE MultiWayIf #-}
+
+foo x = if | x == 5 -> 5
+
+bar x y =
+  if
+    | x > y -> x
+    | x < y ->
+      y
+    | otherwise -> x
diff --git a/data/examples/declaration/value/function/multi-way-if.hs b/data/examples/declaration/value/function/multi-way-if.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/multi-way-if.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE MultiWayIf #-}
+
+foo x = if | x == 5 -> 5
+
+bar x y = if
+    | x > y -> x
+    |  x < y
+        -> y
+    | otherwise  -> x
diff --git a/data/examples/declaration/value/function/multiline-arguments-out.hs b/data/examples/declaration/value/function/multiline-arguments-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/multiline-arguments-out.hs
@@ -0,0 +1,8 @@
+foo :: Int -> Int -> Int -> Int
+foo
+  (Foo g o)
+  ( Bar
+      x
+      y
+    )
+  z = x
diff --git a/data/examples/declaration/value/function/multiline-arguments.hs b/data/examples/declaration/value/function/multiline-arguments.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/multiline-arguments.hs
@@ -0,0 +1,4 @@
+foo :: Int -> Int -> Int -> Int
+foo (Foo g o)
+    (Bar
+       x y) z = x
diff --git a/data/examples/declaration/value/function/multiple-guards-out.hs b/data/examples/declaration/value/function/multiple-guards-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/multiple-guards-out.hs
@@ -0,0 +1,14 @@
+foo :: Int -> Int
+foo x
+  | x == 5 = 10
+  | otherwise = 12
+
+bar :: Int -> Int
+bar x
+  | x == 5 =
+    foo x
+      + foo 10
+  | x == 6 =
+    foo x
+      + foo 20
+  | otherwise = foo 100
diff --git a/data/examples/declaration/value/function/multiple-guards.hs b/data/examples/declaration/value/function/multiple-guards.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/multiple-guards.hs
@@ -0,0 +1,13 @@
+foo :: Int -> Int
+foo x
+  | x == 5 = 10
+  | otherwise = 12
+
+bar :: Int -> Int
+bar x
+  | x == 5 = foo x
+       + foo 10
+  | x == 6 = foo x
+       + foo 20
+  | otherwise = foo 100
+
diff --git a/data/examples/declaration/value/function/multiple-matches-out.hs b/data/examples/declaration/value/function/multiple-matches-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/multiple-matches-out.hs
@@ -0,0 +1,3 @@
+foo :: Int -> Int
+foo 5 = 10
+foo _ = 12
diff --git a/data/examples/declaration/value/function/multiple-matches.hs b/data/examples/declaration/value/function/multiple-matches.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/multiple-matches.hs
@@ -0,0 +1,3 @@
+foo :: Int -> Int
+foo 5 = 10
+foo _ = 12
diff --git a/data/examples/declaration/value/function/negation-out.hs b/data/examples/declaration/value/function/negation-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/negation-out.hs
@@ -0,0 +1,8 @@
+foo :: Int
+foo = (-2)
+
+bar :: Int
+bar = -2
+
+baz :: Int
+baz = - 2
diff --git a/data/examples/declaration/value/function/negation.hs b/data/examples/declaration/value/function/negation.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/negation.hs
@@ -0,0 +1,8 @@
+foo :: Int
+foo = (-2)
+
+bar :: Int
+bar = -2
+
+baz :: Int
+baz = - 2
diff --git a/data/examples/declaration/value/function/newline-single-line-body-out.hs b/data/examples/declaration/value/function/newline-single-line-body-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/newline-single-line-body-out.hs
@@ -0,0 +1,10 @@
+function :: Int -> Int
+function a =
+  aReallyLongFunctionNameThatShouldStayOnThisLineToAvoidOverflowing 10000 a
+
+function' :: String -> String
+function' s = case s of
+  "ThisString" ->
+    -- And a comment here is okay
+    "Yay"
+  _ -> "Boo"
diff --git a/data/examples/declaration/value/function/newline-single-line-body.hs b/data/examples/declaration/value/function/newline-single-line-body.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/newline-single-line-body.hs
@@ -0,0 +1,10 @@
+function :: Int -> Int
+function a =
+  aReallyLongFunctionNameThatShouldStayOnThisLineToAvoidOverflowing 10000 a
+
+function' :: String     -> String
+function' s  =    case s  of
+  "ThisString" -> -- And a comment here is okay
+    "Yay"
+
+  _ -> "Boo"
diff --git a/data/examples/declaration/value/function/operator-comments-0-out.hs b/data/examples/declaration/value/function/operator-comments-0-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/operator-comments-0-out.hs
@@ -0,0 +1,16 @@
+foo =
+  bar
+    ++
+    {- some comment -}
+    case foo of
+      a -> a
+
+foo =
+  bar
+    ++ {- some comment -} case foo of
+      a -> a
+
+foo =
+  bar
+    ++ case foo {- some comment -} of
+      a -> a
diff --git a/data/examples/declaration/value/function/operator-comments-0.hs b/data/examples/declaration/value/function/operator-comments-0.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/operator-comments-0.hs
@@ -0,0 +1,17 @@
+foo =
+  bar
+  ++
+    {- some comment -}
+    case foo of
+      a -> a
+
+foo =
+  bar
+    ++ {- some comment -}
+    case foo of
+      a -> a
+
+foo =
+  bar
+    ++ case foo of {- some comment -}
+      a -> a
diff --git a/data/examples/declaration/value/function/operator-comments-1-out.hs b/data/examples/declaration/value/function/operator-comments-1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/operator-comments-1-out.hs
@@ -0,0 +1,16 @@
+foo =
+  bar
+    ++
+    -- some comment
+    case foo of
+      a -> a
+
+foo =
+  bar
+    ++ case foo of -- some comment
+      a -> a
+
+foo =
+  bar
+    ++ case foo of -- some comment
+      a -> a
diff --git a/data/examples/declaration/value/function/operator-comments-1.hs b/data/examples/declaration/value/function/operator-comments-1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/operator-comments-1.hs
@@ -0,0 +1,17 @@
+foo =
+  bar
+  ++
+    -- some comment
+    case foo of
+      a -> a
+
+foo =
+  bar
+    ++ -- some comment
+    case foo of
+      a -> a
+
+foo =
+  bar
+    ++ case foo of -- some comment
+      a -> a
diff --git a/data/examples/declaration/value/function/operator-sections-out.hs b/data/examples/declaration/value/function/operator-sections-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/operator-sections-out.hs
@@ -0,0 +1,13 @@
+foo = (0 +)
+
+bar = (<> "hello")
+
+baz =
+  ( 1 * 2
+      +
+  )
+    ( *
+        3 ^ 5
+    )
+
+quux = (,) <$> foo <$> bar
diff --git a/data/examples/declaration/value/function/operator-sections.hs b/data/examples/declaration/value/function/operator-sections.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/operator-sections.hs
@@ -0,0 +1,9 @@
+foo = (0  +)
+bar = ( <> "hello" )
+baz =
+    ( 1 * 2
+      + )
+    ( *
+      3 ^ 5)
+
+quux = (,) <$> foo <$> bar
diff --git a/data/examples/declaration/value/function/overindentation-out.hs b/data/examples/declaration/value/function/overindentation-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/overindentation-out.hs
@@ -0,0 +1,9 @@
+reallyincrediblyLongName = f
+  a
+  A
+    { reallyincrediblyLongName = f
+        a
+        A
+          { reallyincrediblyLongName
+          }
+    }
diff --git a/data/examples/declaration/value/function/overindentation.hs b/data/examples/declaration/value/function/overindentation.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/overindentation.hs
@@ -0,0 +1,9 @@
+reallyincrediblyLongName = f
+  a
+  A
+    { reallyincrediblyLongName = f
+        a
+        A
+          { reallyincrediblyLongName
+          }
+    }
diff --git a/data/examples/declaration/value/function/overloaded-labels-out.hs b/data/examples/declaration/value/function/overloaded-labels-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/overloaded-labels-out.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE OverloadedLabels #-}
+
+foo = #field
+
+bar = (#this) (#that)
diff --git a/data/examples/declaration/value/function/overloaded-labels.hs b/data/examples/declaration/value/function/overloaded-labels.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/overloaded-labels.hs
@@ -0,0 +1,4 @@
+{-# LANGUAGE OverloadedLabels #-}
+
+foo = #field
+bar = (#this ) ( #that)
diff --git a/data/examples/declaration/value/function/parallel-comprehensions-complex-out.hs b/data/examples/declaration/value/function/parallel-comprehensions-complex-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/parallel-comprehensions-complex-out.hs
@@ -0,0 +1,35 @@
+baz x y z w =
+  [ ( a,
+      b,
+      c,
+      d,
+      e,
+      f,
+      g,
+      h,
+      i,
+      j
+    )
+    | a <- -- Foo 1
+        x, -- Foo 2
+      b <- -- Bar 1
+        y, -- Bar 2
+      a
+        `mod` b -- Value
+        == 0
+    | c <- -- Baz 1
+        z
+          * z -- Baz 2
+          -- Baz 3
+    | d <- w -- Other
+    | e <- x * x -- Foo bar
+    | f <- -- Foo baz 1
+        y + y -- Foo baz 2
+    | h <- z + z * w ^ 2 -- Bar foo
+    | i <- -- Bar bar 1
+        a
+          + b, -- Bar bar 2
+          -- Bar bar 3
+      j <- -- Bar baz 1
+        a + b -- Bar baz 2
+  ]
diff --git a/data/examples/declaration/value/function/parallel-comprehensions-complex.hs b/data/examples/declaration/value/function/parallel-comprehensions-complex.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/parallel-comprehensions-complex.hs
@@ -0,0 +1,24 @@
+baz x y z w = [
+    (a,b,c,d,e,
+     f,g,h,i,j) |
+    a<-                         -- Foo 1
+      x,                        -- Foo 2
+    b<-                         -- Bar 1
+        y,                      -- Bar 2
+    a
+      `mod` b                   -- Value
+      == 0|
+    c<-                         -- Baz 1
+    z *                         -- Baz 2
+    z|                          -- Baz 3
+    d<- w |                     -- Other
+    e <- x * x |                -- Foo bar
+    f                           -- Foo baz 1
+      <- y + y |                -- Foo baz 2
+     h <- z + z * w ^ 2 |       -- Bar foo
+    i <-                        -- Bar bar 1
+      a +                       -- Bar bar 2
+      b,                        -- Bar bar 3
+    j <-                        -- Bar baz 1
+      a + b                     -- Bar baz 2
+  ]
diff --git a/data/examples/declaration/value/function/parallel-comprehensions-single-line-out.hs b/data/examples/declaration/value/function/parallel-comprehensions-single-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/parallel-comprehensions-single-line-out.hs
@@ -0,0 +1,3 @@
+foo x y = [(a, b) | a <- x | b <- y]
+
+bar x y z w = [(a, b, c, d) | a <- x, b <- y, a `mod` b == 0 | c <- z | d <- w]
diff --git a/data/examples/declaration/value/function/parallel-comprehensions-single-line.hs b/data/examples/declaration/value/function/parallel-comprehensions-single-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/parallel-comprehensions-single-line.hs
@@ -0,0 +1,4 @@
+foo x y = [(a,b) | a<-x | b<-y]
+
+bar x y z w = [(a,b,c,d)  |  a<-x,  b<-y, a`mod`b == 0|c<-z|d<-w ]
+
diff --git a/data/examples/declaration/value/function/parens-out.hs b/data/examples/declaration/value/function/parens-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/parens-out.hs
@@ -0,0 +1,1 @@
+f = p (do foo; bar) baz
diff --git a/data/examples/declaration/value/function/parens.hs b/data/examples/declaration/value/function/parens.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/parens.hs
@@ -0,0 +1,1 @@
+f = p (do foo; bar) baz
diff --git a/data/examples/declaration/value/function/parenthesis-lhs-out.hs b/data/examples/declaration/value/function/parenthesis-lhs-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/parenthesis-lhs-out.hs
@@ -0,0 +1,9 @@
+(!=!) 2 y = 1
+x !=! y = 2
+
+x ?=? [] = 123
+(?=?) x (_ : []) = 456
+x ?=? _ = f x x
+  where
+    f x 7 = 789
+    x `f` _ = 101
diff --git a/data/examples/declaration/value/function/parenthesis-lhs.hs b/data/examples/declaration/value/function/parenthesis-lhs.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/parenthesis-lhs.hs
@@ -0,0 +1,9 @@
+(!=!) 2 y = 1
+x  !=! y = 2
+
+x ?=? [] = 123
+(?=?)   x   (_:[]) = 456
+x ?=? _ = f x x
+  where
+      f x 7 = 789
+      x `f`  _ = 101
diff --git a/data/examples/declaration/value/function/pattern/as-pattern-out.hs b/data/examples/declaration/value/function/pattern/as-pattern-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/as-pattern-out.hs
@@ -0,0 +1,3 @@
+main = case [1] of
+  xs@(x : _) -> print (x, xs)
+  xs@[] -> print xs
diff --git a/data/examples/declaration/value/function/pattern/as-pattern.hs b/data/examples/declaration/value/function/pattern/as-pattern.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/as-pattern.hs
@@ -0,0 +1,3 @@
+main = case [1] of
+  xs @ (x:_) -> print (x, xs)
+  xs@[] -> print xs
diff --git a/data/examples/declaration/value/function/pattern/famous-cardano-pattern-out.hs b/data/examples/declaration/value/function/pattern/famous-cardano-pattern-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/famous-cardano-pattern-out.hs
@@ -0,0 +1,8 @@
+( getNodeSettingsR :<|>
+    getNodeInfoR :<|>
+    getNextUpdateR :<|>
+    restartNodeR
+  ) :<|>
+  ( getUtxoR :<|>
+      getConfirmedProposalsR
+    ) = client nodeV1Api
diff --git a/data/examples/declaration/value/function/pattern/famous-cardano-pattern.hs b/data/examples/declaration/value/function/pattern/famous-cardano-pattern.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/famous-cardano-pattern.hs
@@ -0,0 +1,7 @@
+(       getNodeSettingsR
+ :<|>   getNodeInfoR
+ :<|>   getNextUpdateR
+ :<|>   restartNodeR
+ ):<|>( getUtxoR
+ :<|>   getConfirmedProposalsR
+ ) = client nodeV1Api
diff --git a/data/examples/declaration/value/function/pattern/multiline-case-pattern-out.hs b/data/examples/declaration/value/function/pattern/multiline-case-pattern-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/multiline-case-pattern-out.hs
@@ -0,0 +1,15 @@
+readerBench doc name =
+  runPure $ case (getReader name, getWriter name) of
+    ( Right (TextReader r, rexts),
+      Right (TextWriter w, wexts)
+      ) -> undefined
+
+f xs = case xs of
+  [ a,
+    b
+    ] -> a + b
+
+g xs = case xs of
+  ( a :
+      bs
+    ) -> a + b
diff --git a/data/examples/declaration/value/function/pattern/multiline-case-pattern.hs b/data/examples/declaration/value/function/pattern/multiline-case-pattern.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/multiline-case-pattern.hs
@@ -0,0 +1,12 @@
+readerBench doc name =
+  runPure $ case (getReader name, getWriter name) of
+    (Right (TextReader r, rexts),
+     Right (TextWriter w, wexts)) -> undefined
+
+f xs = case xs of
+  [    a,
+   b       ] -> a + b
+
+g xs = case xs of
+  (a:
+    bs) -> a + b
diff --git a/data/examples/declaration/value/function/pattern/n-plus-k-pattern-out.hs b/data/examples/declaration/value/function/pattern/n-plus-k-pattern-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/n-plus-k-pattern-out.hs
@@ -0,0 +1,13 @@
+{-# LANGUAGE NPlusKPatterns #-}
+
+singleline :: Int
+singleline (n + 1) = n
+
+multiline :: Int
+multiline
+  ( n
+      + 1
+    ) = n
+
+n :: Int
+(n + 1) = 3
diff --git a/data/examples/declaration/value/function/pattern/n-plus-k-pattern.hs b/data/examples/declaration/value/function/pattern/n-plus-k-pattern.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/n-plus-k-pattern.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE NPlusKPatterns #-}
+singleline :: Int
+singleline (n + 1) = n
+
+multiline :: Int
+multiline(n
+  + 1) = n
+
+n :: Int
+(n + 1) = 3
diff --git a/data/examples/declaration/value/function/pattern/pattern-bind-out.hs b/data/examples/declaration/value/function/pattern/pattern-bind-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/pattern-bind-out.hs
@@ -0,0 +1,9 @@
+foo = bar
+  where
+    Foo bar baz = quux
+    Baz
+      quux = zoo
+
+foo = bar
+  where
+    Foo bar baz = quux
diff --git a/data/examples/declaration/value/function/pattern/pattern-bind.hs b/data/examples/declaration/value/function/pattern/pattern-bind.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/pattern-bind.hs
@@ -0,0 +1,9 @@
+foo = bar
+  where
+    Foo bar baz = quux
+    Baz
+      quux = zoo
+
+foo = bar
+  where Foo bar baz = quux
+
diff --git a/data/examples/declaration/value/function/pattern/quasi-quotes-pattern-out.hs b/data/examples/declaration/value/function/pattern/quasi-quotes-pattern-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/quasi-quotes-pattern-out.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+singleline :: ()
+singleline [yamlQQ|something|] = ()
+
+multiline :: ()
+multiline = case y of
+  [yamlQQ| name: John Doe
+age: 23
+|] -> ()
diff --git a/data/examples/declaration/value/function/pattern/quasi-quotes-pattern.hs b/data/examples/declaration/value/function/pattern/quasi-quotes-pattern.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/quasi-quotes-pattern.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE QuasiQuotes #-}
+singleline :: ()
+singleline [yamlQQ|something|] = ()
+
+multiline :: ()
+multiline = case y of
+    [yamlQQ| name: John Doe
+age: 23
+|] -> ()
diff --git a/data/examples/declaration/value/function/pattern/record-patterns-out.hs b/data/examples/declaration/value/function/pattern/record-patterns-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/record-patterns-out.hs
@@ -0,0 +1,19 @@
+foo :: Boom -> Int
+foo Boom {..} = 10
+
+bar0 :: Boom -> Int
+bar0 Boom {boom} = boom
+
+bar1 :: Boom -> Int
+bar1 Boom {boom = b} = b
+
+baz :: Boom -> Int
+baz Boom {boom = b, ..} = b
+
+quux :: Boom -> Int
+quux
+  Boom
+    { boom = a,
+      foom = b,
+      ..
+    } = a + b
diff --git a/data/examples/declaration/value/function/pattern/record-patterns.hs b/data/examples/declaration/value/function/pattern/record-patterns.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/record-patterns.hs
@@ -0,0 +1,18 @@
+foo :: Boom -> Int
+foo Boom {..} = 10
+
+bar0 :: Boom -> Int
+bar0 Boom {boom} = boom
+
+bar1 :: Boom -> Int
+bar1 Boom { boom = b } = b
+
+baz :: Boom -> Int
+baz Boom { boom = b, .. } = b
+
+quux :: Boom -> Int
+quux Boom
+  { boom = a
+  , foom = b
+  , ..
+  } = a + b
diff --git a/data/examples/declaration/value/function/pattern/sig-pattern-out.hs b/data/examples/declaration/value/function/pattern/sig-pattern-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/sig-pattern-out.hs
@@ -0,0 +1,7 @@
+f = do
+  x :: a <- g
+
+f = do
+  (x, y) ::
+    (a, b) <-
+    g
diff --git a/data/examples/declaration/value/function/pattern/sig-pattern.hs b/data/examples/declaration/value/function/pattern/sig-pattern.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/sig-pattern.hs
@@ -0,0 +1,7 @@
+f = do
+  x  ::  a  <-  g
+
+f = do
+  (x, y)
+    :: (a, b)
+    <- g
diff --git a/data/examples/declaration/value/function/pattern/splice-pattern-out.hs b/data/examples/declaration/value/function/pattern/splice-pattern-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/splice-pattern-out.hs
@@ -0,0 +1,13 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+singleLine = case () of
+  $x -> ()
+  $(y "something") -> ()
+
+multiline = case () of
+  $( x
+       + y
+   ) -> ()
+  $( y
+       "something"
+   ) -> ()
diff --git a/data/examples/declaration/value/function/pattern/splice-pattern.hs b/data/examples/declaration/value/function/pattern/splice-pattern.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/splice-pattern.hs
@@ -0,0 +1,11 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+singleLine = case () of
+  $x -> ()
+  $(y "something") -> ()
+
+multiline = case () of
+  $(x
+    + y) -> ()
+  $(y
+      "something") -> ()
diff --git a/data/examples/declaration/value/function/pattern/strictness-out.hs b/data/examples/declaration/value/function/pattern/strictness-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/strictness-out.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE BangPatterns #-}
+
+!a = ()
+
+~b = ()
diff --git a/data/examples/declaration/value/function/pattern/strictness.hs b/data/examples/declaration/value/function/pattern/strictness.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/strictness.hs
@@ -0,0 +1,4 @@
+{-# LANGUAGE BangPatterns #-}
+
+!a = ()
+~b = ()
diff --git a/data/examples/declaration/value/function/pattern/unboxed-sum-pattern-out.hs b/data/examples/declaration/value/function/pattern/unboxed-sum-pattern-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/unboxed-sum-pattern-out.hs
@@ -0,0 +1,26 @@
+{-# LANGUAGE UnboxedSums #-}
+
+v = True
+  where
+    (# _x #) = (# True #)
+
+p = True
+  where
+    (# _x | #) = (# | True #)
+
+q = True
+  where
+    (# | _x | #) = (# | True | #)
+
+z = True
+  where
+    (# | | _x #) = (# | | True #)
+
+z_multiline = True
+  where
+    (#
+      | | _x
+      #) =
+        (#
+          | | True
+        #)
diff --git a/data/examples/declaration/value/function/pattern/unboxed-sum-pattern.hs b/data/examples/declaration/value/function/pattern/unboxed-sum-pattern.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/unboxed-sum-pattern.hs
@@ -0,0 +1,23 @@
+{-# LANGUAGE UnboxedSums #-}
+
+v = True
+  where
+    (# _x #) = (# True #)
+
+p = True
+  where
+    (# _x | #) = (# | True #)
+
+q = True
+  where
+    (# | _x | #) = (# | True | #)
+
+z = True
+  where
+    (# | | _x #) = (# | | True #)
+
+z_multiline = True
+  where
+    (# |
+       | _x #) = (# |
+                    | True #)
diff --git a/data/examples/declaration/value/function/pattern/view-pattern-out.hs b/data/examples/declaration/value/function/pattern/view-pattern-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/view-pattern-out.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE ViewPatterns #-}
+
+example f (f -> 4) = True
+
+f (t -> Nothing) = "Nothing"
+f (t -> Just _) = "Just"
+
+g ((f, _), f -> 4) = True
+
+multiline
+  ( t ->
+      Foo
+        bar
+        baz
+    ) = True
+
+-- https://github.com/tweag/ormolu/issues/343
+foo = (f -> 4)
diff --git a/data/examples/declaration/value/function/pattern/view-pattern.hs b/data/examples/declaration/value/function/pattern/view-pattern.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pattern/view-pattern.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE ViewPatterns #-}
+
+example f (  f    -> 4   ) = True
+
+f (t -> Nothing) = "Nothing"
+f (t -> Just _) = "Just"
+
+g ((f, _), f -> 4) = True
+
+multiline (t -> Foo
+                  bar
+                  baz) = True
+
+-- https://github.com/tweag/ormolu/issues/343
+foo = (f -> 4)
diff --git a/data/examples/declaration/value/function/pragmas-out.hs b/data/examples/declaration/value/function/pragmas-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pragmas-out.hs
@@ -0,0 +1,11 @@
+sccfoo = {-# SCC foo #-} 1
+
+sccbar =
+  {-# SCC "barbaz" #-}
+  "hello"
+
+corefoo = {-# CORE "foo" #-} 1
+
+corebar =
+  {-# CORE "bar baz" #-}
+  "hello"
diff --git a/data/examples/declaration/value/function/pragmas.hs b/data/examples/declaration/value/function/pragmas.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/pragmas.hs
@@ -0,0 +1,7 @@
+sccfoo = {-# SCC foo#-}  1
+sccbar = {-# SCC "barbaz"#-}
+  "hello"
+
+corefoo = {-# CORE "foo"#-}  1
+corebar = {-# CORE "bar baz"#-}
+  "hello"
diff --git a/data/examples/declaration/value/function/prefix-out.hs b/data/examples/declaration/value/function/prefix-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/prefix-out.hs
@@ -0,0 +1,1 @@
+foo x y = (+) x y
diff --git a/data/examples/declaration/value/function/prefix.hs b/data/examples/declaration/value/function/prefix.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/prefix.hs
@@ -0,0 +1,1 @@
+foo x y = (+) x y
diff --git a/data/examples/declaration/value/function/quasi-quotes-out.hs b/data/examples/declaration/value/function/quasi-quotes-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/quasi-quotes-out.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+singleline :: Value
+singleline = [yamlQQ|something|]
+
+multiline :: Value
+multiline =
+  [yamlQQ| name: John Doe
+age: 23
+
+something: foo
+|]
diff --git a/data/examples/declaration/value/function/quasi-quotes.hs b/data/examples/declaration/value/function/quasi-quotes.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/quasi-quotes.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE QuasiQuotes #-}
+singleline :: Value
+singleline = [yamlQQ|something|]
+
+multiline :: Value
+multiline = [yamlQQ| name: John Doe
+age: 23
+
+something: foo
+|]
diff --git a/data/examples/declaration/value/function/record-constructors-out.hs b/data/examples/declaration/value/function/record-constructors-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/record-constructors-out.hs
@@ -0,0 +1,27 @@
+foo = Foo {a = 3}
+
+bar = Bar
+  { abc = foo,
+    def = Foo {a = 10}
+  }
+
+baz = Baz {}
+
+sym = Foo {(+) = 3}
+
+aLongVariableName =
+  ALongRecordName
+    { short = baz,
+      aLongRecordFieldName = YetAnotherLongRecordName
+        { yetAnotherLongRecordFieldName = "a long string"
+        },
+      aLongRecordFieldName2 = Just YetAnotherLongRecordName
+        { yetAnotherLongRecordFieldName = "a long string",
+          yetAnotherLongRecordFieldName =
+            Just
+              "a long string"
+        },
+      aLongRecordFieldName3 = do
+        foo
+        bar
+    }
diff --git a/data/examples/declaration/value/function/record-constructors.hs b/data/examples/declaration/value/function/record-constructors.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/record-constructors.hs
@@ -0,0 +1,22 @@
+foo = Foo { a = 3 }
+bar = Bar {
+    abc = foo,
+    def = Foo {a = 10}
+}
+baz = Baz{ }
+sym = Foo { (+) = 3 }
+aLongVariableName =
+  ALongRecordName
+    { short = baz,
+      aLongRecordFieldName = YetAnotherLongRecordName
+        { yetAnotherLongRecordFieldName = "a long string"
+          },
+      aLongRecordFieldName2 = Just YetAnotherLongRecordName
+                                 { yetAnotherLongRecordFieldName = "a long string",
+                                   yetAnotherLongRecordFieldName = Just
+                                                                     "a long string"
+                                   },
+      aLongRecordFieldName3 = do
+                               foo
+                               bar
+      }
diff --git a/data/examples/declaration/value/function/record-updaters-out.hs b/data/examples/declaration/value/function/record-updaters-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/record-updaters-out.hs
@@ -0,0 +1,11 @@
+foo x = x {a = 3}
+
+bar x =
+  x
+    { abc = foo,
+      def = Foo {a = 10}
+    }
+
+baz x = x {}
+
+sym x = x {(+) = 4}
diff --git a/data/examples/declaration/value/function/record-updaters.hs b/data/examples/declaration/value/function/record-updaters.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/record-updaters.hs
@@ -0,0 +1,7 @@
+foo x = x { a = 3 }
+bar x = x {
+    abc = foo,
+    def = Foo {a = 10}
+}
+baz x = x{ }
+sym x = x { (+) = 4 }
diff --git a/data/examples/declaration/value/function/record-wildcards-out.hs b/data/examples/declaration/value/function/record-wildcards-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/record-wildcards-out.hs
@@ -0,0 +1,13 @@
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE RecordWildCards #-}
+
+foo x y = Foo {x, y}
+
+bar x y z = Bar
+  { x,
+    y,
+    z,
+    ..
+  }
+
+baz = Baz {..}
diff --git a/data/examples/declaration/value/function/record-wildcards.hs b/data/examples/declaration/value/function/record-wildcards.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/record-wildcards.hs
@@ -0,0 +1,13 @@
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE RecordWildCards #-}
+
+foo x y = Foo { x, y }
+
+bar x y z = Bar {
+    x,
+    y,
+    z,
+    ..
+}
+
+baz = Baz { .. }
diff --git a/data/examples/declaration/value/function/simple-out.hs b/data/examples/declaration/value/function/simple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/simple-out.hs
@@ -0,0 +1,3 @@
+bar x = x
+
+baz = x
diff --git a/data/examples/declaration/value/function/simple.hs b/data/examples/declaration/value/function/simple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/simple.hs
@@ -0,0 +1,2 @@
+bar x = x
+baz = x
diff --git a/data/examples/declaration/value/function/splice-out.hs b/data/examples/declaration/value/function/splice-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/splice-out.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+bar = $bar
+
+bar' = $(bar "something")
+
+baz = $$baz
+
+baz' = $$(baz "something")
diff --git a/data/examples/declaration/value/function/splice.hs b/data/examples/declaration/value/function/splice.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/splice.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+bar = $bar
+
+bar' = $(bar "something")
+
+baz = $$baz
+
+baz' = $$(baz "something")
diff --git a/data/examples/declaration/value/function/static-pointers-out.hs b/data/examples/declaration/value/function/static-pointers-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/static-pointers-out.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE StaticPointers #-}
+
+foo :: StaticPtr Int
+foo = static 5
+
+bar :: StaticPtr [Int]
+bar =
+  static
+    [ 1,
+      2,
+      3
+    ]
+
+baz :: StaticPtr Bool
+baz =
+  static
+    ( fun
+        1
+        2
+    )
diff --git a/data/examples/declaration/value/function/static-pointers.hs b/data/examples/declaration/value/function/static-pointers.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/static-pointers.hs
@@ -0,0 +1,13 @@
+{-# LANGUAGE StaticPointers #-}
+
+foo :: StaticPtr Int
+foo = static 5
+
+bar :: StaticPtr [Int]
+bar = static [ 1
+             , 2, 3
+             ]
+
+baz :: StaticPtr Bool
+baz = static (fun 1
+                2)
diff --git a/data/examples/declaration/value/function/strings-out.hs b/data/examples/declaration/value/function/strings-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/strings-out.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE MagicHash #-}
+
+foo = "foobar"
+
+bar = "foo\&barbaz"
+
+baz =
+  "foo\
+  \bar\
+  \baz"
diff --git a/data/examples/declaration/value/function/strings.hs b/data/examples/declaration/value/function/strings.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/strings.hs
@@ -0,0 +1,7 @@
+{-# LANGUAGE MagicHash #-}
+
+foo = "foobar"
+bar = "foo\&bar\   \baz"
+baz = "foo\
+      \bar\
+    \baz"
diff --git a/data/examples/declaration/value/function/tricky-parens-out.hs b/data/examples/declaration/value/function/tricky-parens-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/tricky-parens-out.hs
@@ -0,0 +1,4 @@
+handleStuff =
+  ( let foo = foo
+     in foo
+  )
diff --git a/data/examples/declaration/value/function/tricky-parens.hs b/data/examples/declaration/value/function/tricky-parens.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/tricky-parens.hs
@@ -0,0 +1,4 @@
+handleStuff =
+  ( let foo = foo
+     in foo
+  )
diff --git a/data/examples/declaration/value/function/tuple-sections-out.hs b/data/examples/declaration/value/function/tuple-sections-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/tuple-sections-out.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE TupleSections #-}
+
+foo = (,2)
+
+bar = (,5,)
+
+baz =
+  (,,5,6,7,,,)
diff --git a/data/examples/declaration/value/function/tuple-sections.hs b/data/examples/declaration/value/function/tuple-sections.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/tuple-sections.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE TupleSections #-}
+
+foo = (,2)
+bar = (,5,)
+baz = (
+    ,,5,6,
+    7,,,
+  )
diff --git a/data/examples/declaration/value/function/tuples-out.hs b/data/examples/declaration/value/function/tuples-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/tuples-out.hs
@@ -0,0 +1,14 @@
+foo = (1, 2, 3)
+
+bar =
+  ( 1,
+    2,
+    3
+  )
+
+handleStuff =
+  ( let foo = foo
+     in foo,
+    let bar = bar
+     in bar
+  )
diff --git a/data/examples/declaration/value/function/tuples.hs b/data/examples/declaration/value/function/tuples.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/tuples.hs
@@ -0,0 +1,13 @@
+foo = ( 1,2,3 )
+bar = (
+    1,
+    2,
+    3
+  )
+
+handleStuff =
+  ( let foo = foo
+     in foo
+  , let bar = bar
+     in bar
+  )
diff --git a/data/examples/declaration/value/function/type-applications-out.hs b/data/examples/declaration/value/function/type-applications-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/type-applications-out.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE TypeApplications #-}
+
+foo = f @String a b c
+
+bar = f @(Maybe Int) a b
+
+baz =
+  f @Int @String
+    a
+    b
diff --git a/data/examples/declaration/value/function/type-applications.hs b/data/examples/declaration/value/function/type-applications.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/type-applications.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE TypeApplications #-}
+
+foo = f @String a b c
+
+bar = f @(Maybe Int) a b
+
+baz = f @Int @String
+  a b
diff --git a/data/examples/declaration/value/function/typed-expressions-out.hs b/data/examples/declaration/value/function/typed-expressions-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/typed-expressions-out.hs
@@ -0,0 +1,5 @@
+foo x = x :: Int
+
+bar x =
+  Just x ::
+    Maybe String
diff --git a/data/examples/declaration/value/function/typed-expressions.hs b/data/examples/declaration/value/function/typed-expressions.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/typed-expressions.hs
@@ -0,0 +1,3 @@
+foo x = x::Int
+bar x = Just x ::
+  Maybe String
diff --git a/data/examples/declaration/value/function/typed-hole-out.hs b/data/examples/declaration/value/function/typed-hole-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/typed-hole-out.hs
@@ -0,0 +1,5 @@
+foo = 1 `_` 2
+
+bar = 1 `_a` 2
+
+baz = _ `something` _
diff --git a/data/examples/declaration/value/function/typed-hole.hs b/data/examples/declaration/value/function/typed-hole.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/typed-hole.hs
@@ -0,0 +1,5 @@
+foo = 1 `_` 2
+
+bar = 1 `_a` 2
+
+baz = _ `something` _
diff --git a/data/examples/declaration/value/function/unboxed-string-lit-out.hs b/data/examples/declaration/value/function/unboxed-string-lit-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/unboxed-string-lit-out.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE MagicHash #-}
+
+main = new "p"#
diff --git a/data/examples/declaration/value/function/unboxed-string-lit.hs b/data/examples/declaration/value/function/unboxed-string-lit.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/unboxed-string-lit.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE MagicHash #-}
+
+main = new "p"#
diff --git a/data/examples/declaration/value/function/unboxed-sums-out.hs b/data/examples/declaration/value/function/unboxed-sums-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/unboxed-sums-out.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE UnboxedSums #-}
+
+foo = (# 1 | #)
+
+bar = (# | | 2 | #)
+
+baz =
+  (#
+    | | | 10 | | | | |
+  #)
diff --git a/data/examples/declaration/value/function/unboxed-sums.hs b/data/examples/declaration/value/function/unboxed-sums.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/unboxed-sums.hs
@@ -0,0 +1,7 @@
+{-# LANGUAGE UnboxedSums #-}
+
+foo = (# 1 | #)
+bar = (# | |2| #)
+baz = (# |
+  | | 10 | | | |
+  | #)
diff --git a/data/examples/declaration/value/function/unboxed-tuples-out.hs b/data/examples/declaration/value/function/unboxed-tuples-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/unboxed-tuples-out.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE UnboxedTuples #-}
+
+foo = (# 1, 2, 3 #)
+
+bar =
+  (#
+    1,
+    2,
+    3
+  #)
diff --git a/data/examples/declaration/value/function/unboxed-tuples.hs b/data/examples/declaration/value/function/unboxed-tuples.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/unboxed-tuples.hs
@@ -0,0 +1,7 @@
+{-# LANGUAGE UnboxedTuples #-}
+
+foo = (# 1,2,3 #)
+bar = (#
+    1,
+    2,
+    3 #)
diff --git a/data/examples/declaration/value/function/where-nested-out.hs b/data/examples/declaration/value/function/where-nested-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/where-nested-out.hs
@@ -0,0 +1,12 @@
+foo = bar
+  where
+    f1 = f1
+      where
+        f1 = 3
+    f2 = f2
+      where
+        f2 = 3
+
+foo2 = bar
+  where
+    f1 = f1 where { f1 = 3; f1' = 4 }; f2 = f2 where f2 = 3; f2' = 4
diff --git a/data/examples/declaration/value/function/where-nested.hs b/data/examples/declaration/value/function/where-nested.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/where-nested.hs
@@ -0,0 +1,12 @@
+foo = bar
+  where
+    f1 = f1
+      where
+        f1 = 3
+    f2 = f2
+      where
+        f2 = 3
+
+foo2 = bar
+  where
+   { f1 = f1 where { f1 = 3; f1' = 4 }; f2 = f2 where { f2 = 3; f2' = 4 } }
diff --git a/data/examples/declaration/value/function/where-out.hs b/data/examples/declaration/value/function/where-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/where-out.hs
@@ -0,0 +1,19 @@
+foo :: Int -> Int
+foo x = f x where f z = z
+
+bar :: Int -> Int
+bar x = f x
+  where
+    f :: Int -> Int
+    f z = z
+
+baz :: Int -> Int
+baz x = q
+  where
+    y = x
+    z = y
+    q = z
+
+emptyWhere :: Int
+emptyWhere = 5
+  where
diff --git a/data/examples/declaration/value/function/where.hs b/data/examples/declaration/value/function/where.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/where.hs
@@ -0,0 +1,19 @@
+foo :: Int -> Int
+foo x = f x where f z = z
+
+bar :: Int -> Int
+bar x = f x
+  where
+    f :: Int -> Int
+    f z = z
+
+baz :: Int -> Int
+baz x = q
+  where
+    y = x
+    z = y
+    q = z
+
+emptyWhere :: Int
+emptyWhere = 5
+  where
diff --git a/data/examples/declaration/value/other/comments-get-before-op-out.hs b/data/examples/declaration/value/other/comments-get-before-op-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/other/comments-get-before-op-out.hs
@@ -0,0 +1,10 @@
+main :: IO ()
+main = do
+  migrateSchema
+    [ migration1,
+      migration1,
+      migration3
+      -- When adding migrations here, don't forget to update
+      -- 'schemaVersion' in Galley.Data
+    ]
+    `finally` Log.close
diff --git a/data/examples/declaration/value/other/comments-get-before-op.hs b/data/examples/declaration/value/other/comments-get-before-op.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/other/comments-get-before-op.hs
@@ -0,0 +1,11 @@
+main :: IO ()
+main = do
+    migrateSchema
+        [ migration1
+        , migration1
+        , migration3
+        -- When adding migrations here, don't forget to update
+        -- 'schemaVersion' in Galley.Data
+        ]
+      `finally`
+        Log.close
diff --git a/data/examples/declaration/value/other/line-multi-line-out.hs b/data/examples/declaration/value/other/line-multi-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/other/line-multi-line-out.hs
@@ -0,0 +1,6 @@
+x :: [Int]
+x =
+  [ 1,
+    2,
+    somethingSomething 3
+  ]
diff --git a/data/examples/declaration/value/other/line-multi-line.hs b/data/examples/declaration/value/other/line-multi-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/other/line-multi-line.hs
@@ -0,0 +1,6 @@
+x :: [Int]
+x = [
+  1
+  , 2
+  , somethingSomething 3
+  ]
diff --git a/data/examples/declaration/value/other/line-single-line-out.hs b/data/examples/declaration/value/other/line-single-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/other/line-single-line-out.hs
@@ -0,0 +1,2 @@
+x :: [Int]
+x = [1, 2, 3]
diff --git a/data/examples/declaration/value/other/line-single-line.hs b/data/examples/declaration/value/other/line-single-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/other/line-single-line.hs
@@ -0,0 +1,2 @@
+x :: [Int]
+x = [1,2,3]
diff --git a/data/examples/declaration/value/pattern-synonyms/bidirectional-out.hs b/data/examples/declaration/value/pattern-synonyms/bidirectional-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/pattern-synonyms/bidirectional-out.hs
@@ -0,0 +1,28 @@
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE PatternSynonyms #-}
+
+pattern Arrow t1 t2 = App "->" [t1, t2]
+
+pattern Arrow {t1, t2} = App "->" [t1, t2]
+
+pattern Arrow
+  { t1,
+    t2
+  } =
+  App "->" [t1, t2]
+
+pattern Int =
+  App "Int" []
+
+pattern Maybe {t} =
+  App
+    "Maybe"
+    [t]
+
+pattern Maybe t =
+  App
+    "Maybe"
+    [t]
+
+pattern a :< b <-
+  (a, b)
diff --git a/data/examples/declaration/value/pattern-synonyms/bidirectional.hs b/data/examples/declaration/value/pattern-synonyms/bidirectional.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/pattern-synonyms/bidirectional.hs
@@ -0,0 +1,21 @@
+{-# LANGUAGE PatternSynonyms #-}
+{-# LANGUAGE NamedFieldPuns #-}
+
+pattern Arrow t1 t2 = App "->"    [t1, t2]
+pattern Arrow{t1,t2} = App "->"    [t1,t2]
+pattern Arrow{t1
+             , t2} = App "->" [t1, t2]
+pattern Int         =
+  App "Int"   []
+pattern Maybe{t}    =
+  App
+    "Maybe"
+    [t]
+pattern Maybe t     =
+  App
+    "Maybe"
+    [t]
+
+pattern a :< b <-
+  (a , b)
+
diff --git a/data/examples/declaration/value/pattern-synonyms/explicitely-bidirectional-out.hs b/data/examples/declaration/value/pattern-synonyms/explicitely-bidirectional-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/pattern-synonyms/explicitely-bidirectional-out.hs
@@ -0,0 +1,21 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+pattern HeadC x <-
+  x : xs
+  where
+    HeadC x = [x]
+
+pattern HeadC' x <-
+  x : xs
+  where
+    HeadC' x = [x]
+
+pattern Simple <-
+  "Simple"
+  where
+    Simple = "Complicated"
+
+pattern a :< b <-
+  (a, b)
+  where
+    a :< b = (a, b)
diff --git a/data/examples/declaration/value/pattern-synonyms/explicitely-bidirectional.hs b/data/examples/declaration/value/pattern-synonyms/explicitely-bidirectional.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/pattern-synonyms/explicitely-bidirectional.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+pattern HeadC x <- x:xs where
+  HeadC x = [x]
+
+pattern HeadC' x <-
+  x:xs
+  where
+    HeadC' x = [x]
+
+pattern Simple <- "Simple"
+  where
+    Simple = "Complicated"
+
+pattern a :< b <-
+  (a , b)
+  where
+    a :< b = (a, b)
+
diff --git a/data/examples/declaration/value/pattern-synonyms/unidirectional-out.hs b/data/examples/declaration/value/pattern-synonyms/unidirectional-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/pattern-synonyms/unidirectional-out.hs
@@ -0,0 +1,23 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+pattern Head x <- x : xs
+
+pattern Head' x <-
+  x : xs
+
+pattern Head'' {x} <-
+  x : xs
+
+pattern FirstTwo {x, y} <-
+  x : (y : xs)
+
+pattern FirstTwo'
+  { x,
+    y
+  } <-
+  x : (y : xs)
+
+pattern Simple <- "Simple"
+
+pattern WithTypeSig :: String
+pattern WithTypeSig <- "WithTypeSig"
diff --git a/data/examples/declaration/value/pattern-synonyms/unidirectional.hs b/data/examples/declaration/value/pattern-synonyms/unidirectional.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/pattern-synonyms/unidirectional.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+pattern Head x <- x:xs
+
+pattern Head' x
+  <- x:xs
+
+pattern Head''{x}
+  <- x:xs
+
+pattern FirstTwo{x,y}
+  <- x : (y : xs)
+
+pattern FirstTwo'{x
+                 , y} <- x : (y:xs)
+
+pattern Simple <- "Simple"
+
+pattern WithTypeSig :: String
+pattern WithTypeSig <- "WithTypeSig"
diff --git a/data/examples/declaration/warning/warning-multiline-out.hs b/data/examples/declaration/warning/warning-multiline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/warning/warning-multiline-out.hs
@@ -0,0 +1,9 @@
+{-# WARNING
+  test,
+  foo
+  [ "These are bad functions",
+    "Really bad!"
+  ]
+  #-}
+test :: IO ()
+test = pure ()
diff --git a/data/examples/declaration/warning/warning-multiline.hs b/data/examples/declaration/warning/warning-multiline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/warning/warning-multiline.hs
@@ -0,0 +1,4 @@
+{-# WArNING test,
+  foo ["These are bad functions", "Really bad!"] #-}
+test :: IO ()
+test = pure ()
diff --git a/data/examples/declaration/warning/warning-single-line-out.hs b/data/examples/declaration/warning/warning-single-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/warning/warning-single-line-out.hs
@@ -0,0 +1,13 @@
+{-# DEPRECATED test, foo "This is a deprecation" #-}
+{-# WARNING test "This is a warning" #-}
+test :: IO ()
+test = pure ()
+
+bar = 3
+{-# DEPRECATED bar "Bar is deprecated" #-}
+
+{-# DEPRECATED baz "Baz is also deprecated" #-}
+baz = 5
+
+data Number = Number Dobule
+{-# DEPRECATED Number "Use Scientific instead." #-}
diff --git a/data/examples/declaration/warning/warning-single-line.hs b/data/examples/declaration/warning/warning-single-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/warning/warning-single-line.hs
@@ -0,0 +1,15 @@
+{-# Deprecated test, foo "This is a deprecation"
+  #-}
+{-# WARNING test    ["This is a warning" ] #-}
+test :: IO ()
+test = pure ()
+
+bar = 3
+
+{-# Deprecated bar "Bar is deprecated" #-}
+
+{-# DEPRECATED baz "Baz is also deprecated" #-}
+baz = 5
+
+data Number = Number Dobule
+{-# DEPRECATED Number "Use Scientific instead." #-}
diff --git a/data/examples/import/comments-inside-imports-out.hs b/data/examples/import/comments-inside-imports-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/comments-inside-imports-out.hs
@@ -0,0 +1,7 @@
+-- x
+
+import qualified -- x
+  Bar
+import qualified -- x
+  Baz
+import Foo
diff --git a/data/examples/import/comments-inside-imports.hs b/data/examples/import/comments-inside-imports.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/comments-inside-imports.hs
@@ -0,0 +1,9 @@
+import -- x
+   Foo
+
+import -- x
+  qualified Bar
+
+import qualified
+  -- x
+  Baz
diff --git a/data/examples/import/comments-per-import-out.hs b/data/examples/import/comments-per-import-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/comments-per-import-out.hs
@@ -0,0 +1,4 @@
+-- (1)
+import Bar -- (2)
+import Baz -- (3)
+import Foo
diff --git a/data/examples/import/comments-per-import.hs b/data/examples/import/comments-per-import.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/comments-per-import.hs
@@ -0,0 +1,3 @@
+import Foo -- (1)
+import Bar -- (2)
+import Baz -- (3)
diff --git a/data/examples/import/explicit-imports-out.hs b/data/examples/import/explicit-imports-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/explicit-imports-out.hs
@@ -0,0 +1,12 @@
+import qualified MegaModule as M
+  ( (<<<),
+    (>>>),
+    Either,
+    Maybe (Just, Nothing),
+    MaybeT (..),
+    Monad ((>>), (>>=), return),
+    MonadBaseControl,
+    join,
+    liftIO,
+    void,
+  )
diff --git a/data/examples/import/explicit-imports-with-comments-out.hs b/data/examples/import/explicit-imports-with-comments-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/explicit-imports-with-comments-out.hs
@@ -0,0 +1,6 @@
+import qualified MegaModule as M
+  ( -- (1)
+    (<<<), -- (2)
+    (>>>),
+    Either, -- (3)
+  )
diff --git a/data/examples/import/explicit-imports-with-comments.hs b/data/examples/import/explicit-imports-with-comments.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/explicit-imports-with-comments.hs
@@ -0,0 +1,5 @@
+import qualified MegaModule as M
+  ( (>>>) -- (1)
+  , (<<<) -- (2)
+  , Either -- (3)
+  )
diff --git a/data/examples/import/explicit-imports.hs b/data/examples/import/explicit-imports.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/explicit-imports.hs
@@ -0,0 +1,2 @@
+import qualified MegaModule as M
+  ((>>>), MonadBaseControl, void, MaybeT(..), join, Maybe(Nothing, Just), liftIO, Either, (<<<), Monad(return, (>>=), (>>)))
diff --git a/data/examples/import/explicit-prelude-out.hs b/data/examples/import/explicit-prelude-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/explicit-prelude-out.hs
@@ -0,0 +1,3 @@
+import Aaa
+import Zzz
+import Prelude
diff --git a/data/examples/import/explicit-prelude.hs b/data/examples/import/explicit-prelude.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/explicit-prelude.hs
@@ -0,0 +1,3 @@
+import Aaa
+import Prelude
+import Zzz
diff --git a/data/examples/import/misc-out.hs b/data/examples/import/misc-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/misc-out.hs
@@ -0,0 +1,11 @@
+import A hiding
+  ( foobarbazqux,
+    foobarbazqux,
+    foobarbazqux,
+    foobarbazqux,
+    foobarbazqux,
+    foobarbazqux,
+    foobarbazqux,
+  )
+import {-# SOURCE #-} safe qualified Module as M hiding (a, b, c, d, e, f)
+import Name hiding ()
diff --git a/data/examples/import/misc.hs b/data/examples/import/misc.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/misc.hs
@@ -0,0 +1,13 @@
+import A hiding
+  ( foobarbazqux
+  , foobarbazqux
+  , foobarbazqux
+  , foobarbazqux
+  , foobarbazqux
+  , foobarbazqux
+  , foobarbazqux
+  )
+
+import Name hiding ()
+
+import {-# SOURCE #-} safe qualified Module as M hiding (a, b, c, d, e, f)
diff --git a/data/examples/import/nested-explicit-imports-out.hs b/data/examples/import/nested-explicit-imports-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/nested-explicit-imports-out.hs
@@ -0,0 +1,10 @@
+import qualified MegaModule as M
+  ( (<<<),
+    (>>>),
+    Either,
+    Monad
+      ( (>>),
+        (>>=),
+        return
+      ),
+  )
diff --git a/data/examples/import/nested-explicit-imports.hs b/data/examples/import/nested-explicit-imports.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/nested-explicit-imports.hs
@@ -0,0 +1,2 @@
+import qualified MegaModule as M ((>>>), Either, (<<<), Monad(
+  return, (>>=), (>>)))
diff --git a/data/examples/import/qualified-prelude-out.hs b/data/examples/import/qualified-prelude-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/qualified-prelude-out.hs
@@ -0,0 +1,4 @@
+module P where
+
+import Prelude hiding ((.), id)
+import qualified Prelude
diff --git a/data/examples/import/qualified-prelude.hs b/data/examples/import/qualified-prelude.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/qualified-prelude.hs
@@ -0,0 +1,4 @@
+module P where
+
+import Prelude hiding (id, (.))
+import qualified Prelude
diff --git a/data/examples/import/simple-out.hs b/data/examples/import/simple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/simple-out.hs
@@ -0,0 +1,6 @@
+import Data.Text
+import Data.Text
+import qualified Data.Text as T
+import qualified Data.Text (a, b, c)
+import Data.Text (a, b, c)
+import Data.Text hiding (a, b, c)
diff --git a/data/examples/import/simple.hs b/data/examples/import/simple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/simple.hs
@@ -0,0 +1,6 @@
+import Data.Text
+import Data.Text
+import qualified Data.Text as T
+import qualified Data.Text (a, c, b)
+import Data.Text (a, b, c)
+import Data.Text hiding (c, b, a)
diff --git a/data/examples/import/sorted-out.hs b/data/examples/import/sorted-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/sorted-out.hs
@@ -0,0 +1,3 @@
+import A
+import B
+import C
diff --git a/data/examples/import/sorted.hs b/data/examples/import/sorted.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/sorted.hs
@@ -0,0 +1,3 @@
+import B
+import A
+import C
diff --git a/data/examples/module-header/double-dot-with-names-out.hs b/data/examples/module-header/double-dot-with-names-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/double-dot-with-names-out.hs
@@ -0,0 +1,22 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+module ExportSyntax
+  ( A (.., NoA),
+    Q (F, ..),
+    G (T, .., U),
+  )
+where
+
+data A = A | B
+
+pattern NoA = B
+
+data Q a = Q a
+
+pattern F a = Q a
+
+data G = G | H
+
+pattern T = G
+
+pattern U = H
diff --git a/data/examples/module-header/double-dot-with-names.hs b/data/examples/module-header/double-dot-with-names.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/double-dot-with-names.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+module ExportSyntax ( A(.., NoA), Q(F,..), G(T,..,U)) where
+
+data A = A | B
+
+pattern NoA = B
+
+data Q a = Q a
+
+pattern F a = Q a
+
+data G = G | H
+
+pattern T = G
+
+pattern U = H
diff --git a/data/examples/module-header/double-shebangs-out.hs b/data/examples/module-header/double-shebangs-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/double-shebangs-out.hs
@@ -0,0 +1,2 @@
+#!/usr/bin/env stack
+#!/usr/bin/env stack
diff --git a/data/examples/module-header/double-shebangs.hs b/data/examples/module-header/double-shebangs.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/double-shebangs.hs
@@ -0,0 +1,2 @@
+#!/usr/bin/env stack
+#!/usr/bin/env stack
diff --git a/data/examples/module-header/empty-out.hs b/data/examples/module-header/empty-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/empty-out.hs
diff --git a/data/examples/module-header/empty.hs b/data/examples/module-header/empty.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/empty.hs
diff --git a/data/examples/module-header/leading-empty-line-out.hs b/data/examples/module-header/leading-empty-line-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/leading-empty-line-out.hs
@@ -0,0 +1,11 @@
+-- |
+-- Module      :  Text.Megaparsec
+-- Copyright   :  © 2015–2019 Megaparsec contributors
+--                © 2007 Paolo Martini
+--                © 1999–2001 Daan Leijen
+-- License     :  FreeBSD
+--
+-- Maintainer  :  Mark Karpov <markkarpov92@gmail.com>
+-- Stability   :  experimental
+-- Portability :  portable
+module Main where
diff --git a/data/examples/module-header/leading-empty-line.hs b/data/examples/module-header/leading-empty-line.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/leading-empty-line.hs
@@ -0,0 +1,11 @@
+-- |
+-- Module      :  Text.Megaparsec
+-- Copyright   :  © 2015–2019 Megaparsec contributors
+--                © 2007 Paolo Martini
+--                © 1999–2001 Daan Leijen
+-- License     :  FreeBSD
+--
+-- Maintainer  :  Mark Karpov <markkarpov92@gmail.com>
+-- Stability   :  experimental
+-- Portability :  portable
+module Main where
diff --git a/data/examples/module-header/multiline-empty-out.hs b/data/examples/module-header/multiline-empty-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/multiline-empty-out.hs
@@ -0,0 +1,4 @@
+module Foo
+  (
+  )
+where
diff --git a/data/examples/module-header/multiline-empty.hs b/data/examples/module-header/multiline-empty.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/multiline-empty.hs
@@ -0,0 +1,2 @@
+module Foo (
+           ) where
diff --git a/data/examples/module-header/multiline-out.hs b/data/examples/module-header/multiline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/multiline-out.hs
@@ -0,0 +1,6 @@
+module Foo
+  ( foo,
+    bar,
+    baz,
+  )
+where
diff --git a/data/examples/module-header/multiline-with-comments-out.hs b/data/examples/module-header/multiline-with-comments-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/multiline-with-comments-out.hs
@@ -0,0 +1,22 @@
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE TypeFamilies #-}
+
+-- | Header.
+module My.Module
+  ( -- * Something
+    foo,
+    bar,
+
+    -- * Another thing
+    (<?>),
+    {- some other thing -} foo2, -- yet another
+    foo3, -- third one
+    baz,
+    bar2, -- a multiline comment
+    -- the second line
+    bar3,
+    module Foo.Bar.Baz,
+  )
+where
+
+-- Wow
diff --git a/data/examples/module-header/multiline-with-comments.hs b/data/examples/module-header/multiline-with-comments.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/multiline-with-comments.hs
@@ -0,0 +1,21 @@
+-- | Header.
+
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE TypeFamilies     #-}
+
+module My.Module
+  ( -- * Something
+    foo,
+    bar,
+    -- * Another thing
+    (<?>),
+    {- some other thing -} foo2 -- yet another
+    ,foo3 -- third one
+    ,baz,
+    bar2 -- a multiline comment
+         -- the second line
+    ,bar3
+  , module Foo.Bar.Baz )
+where
+
+-- Wow
diff --git a/data/examples/module-header/multiline.hs b/data/examples/module-header/multiline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/multiline.hs
@@ -0,0 +1,2 @@
+module Foo (
+  foo, bar, baz) where
diff --git a/data/examples/module-header/multiline2-out.hs b/data/examples/module-header/multiline2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/multiline2-out.hs
@@ -0,0 +1,6 @@
+module Foo
+  ( foo,
+    bar,
+    baz,
+  )
+where
diff --git a/data/examples/module-header/multiline2.hs b/data/examples/module-header/multiline2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/multiline2.hs
@@ -0,0 +1,2 @@
+module Foo
+  (foo, bar, baz) where
diff --git a/data/examples/module-header/named-section-out.hs b/data/examples/module-header/named-section-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/named-section-out.hs
@@ -0,0 +1,13 @@
+module Magic
+  ( -- * Something
+    -- $explanation
+
+    -- ** Another level
+    foo,
+    bar,
+  )
+where
+
+-- $explanation
+--
+-- Here it goes.
diff --git a/data/examples/module-header/named-section.hs b/data/examples/module-header/named-section.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/named-section.hs
@@ -0,0 +1,13 @@
+module Magic
+  ( -- * Something
+    -- $explanation
+
+    -- ** Another level
+    foo
+  , bar
+  )
+where
+
+-- $explanation
+--
+-- Here it goes.
diff --git a/data/examples/module-header/shebang-out.hs b/data/examples/module-header/shebang-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/shebang-out.hs
@@ -0,0 +1,5 @@
+#! /usr/bin/env runhaskell
+import Prelude
+
+main :: IO ()
+main = putStrLn "hello world"
diff --git a/data/examples/module-header/shebang.hs b/data/examples/module-header/shebang.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/shebang.hs
@@ -0,0 +1,5 @@
+#! /usr/bin/env runhaskell
+import Prelude
+
+main :: IO ()
+main = putStrLn "hello world"
diff --git a/data/examples/module-header/simple-out.hs b/data/examples/module-header/simple-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/simple-out.hs
@@ -0,0 +1,1 @@
+module Main where
diff --git a/data/examples/module-header/simple-with-comments-out.hs b/data/examples/module-header/simple-with-comments-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/simple-with-comments-out.hs
@@ -0,0 +1,4 @@
+-- | Here we go.
+module Main where
+
+-- Wow.
diff --git a/data/examples/module-header/simple-with-comments.hs b/data/examples/module-header/simple-with-comments.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/simple-with-comments.hs
@@ -0,0 +1,5 @@
+-- | Here we go.
+
+module Main where
+
+-- Wow.
diff --git a/data/examples/module-header/simple.hs b/data/examples/module-header/simple.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/simple.hs
@@ -0,0 +1,1 @@
+module Main where
diff --git a/data/examples/module-header/singleline-empty-out.hs b/data/examples/module-header/singleline-empty-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/singleline-empty-out.hs
@@ -0,0 +1,5 @@
+-- | This demonstrates a BUG.
+module Foo
+  (
+  )
+where
diff --git a/data/examples/module-header/singleline-empty.hs b/data/examples/module-header/singleline-empty.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/singleline-empty.hs
@@ -0,0 +1,2 @@
+-- | This demonstrates a BUG.
+module Foo () where
diff --git a/data/examples/module-header/singleline-out.hs b/data/examples/module-header/singleline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/singleline-out.hs
@@ -0,0 +1,1 @@
+module Foo (foo, bar, baz) where
diff --git a/data/examples/module-header/singleline.hs b/data/examples/module-header/singleline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/singleline.hs
@@ -0,0 +1,1 @@
+module Foo ( foo, bar, baz ) where
diff --git a/data/examples/module-header/warning-pragma-list-multiline-out.hs b/data/examples/module-header/warning-pragma-list-multiline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/warning-pragma-list-multiline-out.hs
@@ -0,0 +1,11 @@
+module Test
+  {-# DEPRECATED
+    [ "This module is deprecated.",
+      "Please use OtherModule instead."
+    ]
+    #-}
+  ( foo,
+    bar,
+    baz,
+  )
+where
diff --git a/data/examples/module-header/warning-pragma-list-multiline.hs b/data/examples/module-header/warning-pragma-list-multiline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/warning-pragma-list-multiline.hs
@@ -0,0 +1,8 @@
+module Test {-# DEPRECATED ["This module is deprecated.",
+  "Please use OtherModule instead."
+ ]#-}
+  ( foo
+  , bar
+  , baz
+  )
+where
diff --git a/data/examples/module-header/warning-pragma-multiline-out.hs b/data/examples/module-header/warning-pragma-multiline-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/warning-pragma-multiline-out.hs
@@ -0,0 +1,9 @@
+module Test
+  {-# DEPRECATED "This module is unstable" #-}
+  ( foo,
+    bar,
+    baz,
+  )
+where
+
+import Blah
diff --git a/data/examples/module-header/warning-pragma-multiline.hs b/data/examples/module-header/warning-pragma-multiline.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/warning-pragma-multiline.hs
@@ -0,0 +1,4 @@
+module Test {-# DEPRECATED "This module is unstable" #-}
+  (foo, bar, baz) where
+
+import Blah
diff --git a/data/examples/module-header/warning-pragma-out.hs b/data/examples/module-header/warning-pragma-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/warning-pragma-out.hs
@@ -0,0 +1,3 @@
+module Test
+  {-# WARNING "This module is very internal" #-}
+where
diff --git a/data/examples/module-header/warning-pragma-singleton-list-out.hs b/data/examples/module-header/warning-pragma-singleton-list-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/warning-pragma-singleton-list-out.hs
@@ -0,0 +1,1 @@
+module Test {-# WARNING "There's only one line here." #-} where
diff --git a/data/examples/module-header/warning-pragma-singleton-list.hs b/data/examples/module-header/warning-pragma-singleton-list.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/warning-pragma-singleton-list.hs
@@ -0,0 +1,1 @@
+module Test {-# WArnING ["There's only one line here."]     #-} where
diff --git a/data/examples/module-header/warning-pragma.hs b/data/examples/module-header/warning-pragma.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/module-header/warning-pragma.hs
@@ -0,0 +1,2 @@
+module Test {-# WARNING "This module is very internal"
+  #-} where
diff --git a/data/examples/other/argument-comment-out.hs b/data/examples/other/argument-comment-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/argument-comment-out.hs
@@ -0,0 +1,17 @@
+foo ::
+  -- | Documentation
+  Int ->
+  Bool
+foo _ = True
+
+foo ::
+  Foo a =>
+  -- | Foo
+  Int ->
+  Int
+
+foo ::
+  Foo a =>
+  -- | Foo
+  Int ->
+  Int
diff --git a/data/examples/other/argument-comment.hs b/data/examples/other/argument-comment.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/argument-comment.hs
@@ -0,0 +1,13 @@
+foo
+  :: Int -- ^ Documentation
+  -> Bool
+foo _ = True
+
+foo :: Foo a
+  => Int -- ^ Foo
+  -> Int
+
+foo
+  :: Foo a
+  => Int -- ^ Foo
+  -> Int
diff --git a/data/examples/other/ascii-out.hs b/data/examples/other/ascii-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/ascii-out.hs
@@ -0,0 +1,9 @@
+{- -----------------------------------
+  < What about ASCII art in comments? >
+   -----------------------------------
+          \   ^__^
+           \  (oo)\_______
+              (__)\       )\/\
+                  ||----w |
+                  ||     ||
+-}
diff --git a/data/examples/other/ascii.hs b/data/examples/other/ascii.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/ascii.hs
@@ -0,0 +1,9 @@
+{- -----------------------------------
+  < What about ASCII art in comments? >
+   -----------------------------------
+          \   ^__^
+           \  (oo)\_______
+              (__)\       )\/\
+                  ||----w |
+                  ||     ||
+-}
diff --git a/data/examples/other/comment-alignment-out.hs b/data/examples/other/comment-alignment-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-alignment-out.hs
@@ -0,0 +1,10 @@
+class Foo a where
+
+  -- | Foo.
+  foo ::
+    Int ->
+    -- | Something
+    a
+
+  -- | Bar.
+  bar :: a
diff --git a/data/examples/other/comment-alignment.hs b/data/examples/other/comment-alignment.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-alignment.hs
@@ -0,0 +1,11 @@
+class Foo a where
+
+  -- | Foo.
+
+  foo
+    :: Int
+    -> a -- ^ Something
+
+  -- | Bar.
+
+  bar :: a
diff --git a/data/examples/other/comment-following-preceding-gap-out.hs b/data/examples/other/comment-following-preceding-gap-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-following-preceding-gap-out.hs
@@ -0,0 +1,6 @@
+foo = bar
+  where
+    baz = return (quux) -- Foo
+
+    -- Bar
+    meme = gege
diff --git a/data/examples/other/comment-following-preceding-gap.hs b/data/examples/other/comment-following-preceding-gap.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-following-preceding-gap.hs
@@ -0,0 +1,6 @@
+foo = bar
+  where
+    baz = return (quux) -- Foo
+
+    -- Bar
+    meme = gege
diff --git a/data/examples/other/comment-inside-construct-out.hs b/data/examples/other/comment-inside-construct-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-inside-construct-out.hs
@@ -0,0 +1,8 @@
+xs =
+  [ outer list item,
+    [ inner list first item,
+      inner list second item
+      -- inner list last item commented
+    ],
+    outer list item
+  ]
diff --git a/data/examples/other/comment-inside-construct.hs b/data/examples/other/comment-inside-construct.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-inside-construct.hs
@@ -0,0 +1,9 @@
+xs =
+  [ outer list item,
+    [ inner list first item,
+      inner list second item
+      -- inner list last item commented
+    ],
+    outer list item
+  ]
+
diff --git a/data/examples/other/comment-multiline-after-out.hs b/data/examples/other/comment-multiline-after-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-multiline-after-out.hs
@@ -0,0 +1,7 @@
+foo ::
+  -- | start index
+  Int ->
+  -- | length
+  Int ->
+  t a ->
+  t a
diff --git a/data/examples/other/comment-multiline-after.hs b/data/examples/other/comment-multiline-after.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-multiline-after.hs
@@ -0,0 +1,1 @@
+foo :: Int {- ^ start index -} -> Int {- ^ length -} -> t a -> t a
diff --git a/data/examples/other/comment-style-transform-out.hs b/data/examples/other/comment-style-transform-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-style-transform-out.hs
@@ -0,0 +1,17 @@
+-- |
+-- Module:      Data.Aeson.TH
+-- Copyright:   (c) 2011-2016 Bryan O'Sullivan
+--              (c) 2011 MailRank, Inc.
+-- License:     BSD3
+-- Stability:   experimental
+-- Portability: portable
+module Main where
+
+-- |
+--
+-- Here is a snippet:
+--
+-- @
+-- x = y + 2
+-- @
+x = y + 2
diff --git a/data/examples/other/comment-style-transform.hs b/data/examples/other/comment-style-transform.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-style-transform.hs
@@ -0,0 +1,22 @@
+{-|
+Module:      Data.Aeson.TH
+Copyright:   (c) 2011-2016 Bryan O'Sullivan
+             (c) 2011 MailRank, Inc.
+License:     BSD3
+Stability:   experimental
+Portability: portable
+-}
+
+module Main where
+
+{- |
+
+Here is a snippet:
+
+@
+x = y + 2
+@
+
+-}
+
+x = y + 2
diff --git a/data/examples/other/comment-two-blocks-out.hs b/data/examples/other/comment-two-blocks-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-two-blocks-out.hs
@@ -0,0 +1,8 @@
+newNames :: [(String, String)]
+newNames =
+  let (*) = flip (,)
+   in [ "Control" * "Monad"
+        -- Foo
+
+        -- Bar
+      ]
diff --git a/data/examples/other/comment-two-blocks.hs b/data/examples/other/comment-two-blocks.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/comment-two-blocks.hs
@@ -0,0 +1,9 @@
+newNames :: [(String, String)]
+newNames = let (*) = flip (,) in
+    ["Control" * "Monad"
+
+    -- Foo
+
+    -- Bar
+
+    ]
diff --git a/data/examples/other/consequetive-pipe-comments-out.hs b/data/examples/other/consequetive-pipe-comments-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/consequetive-pipe-comments-out.hs
@@ -0,0 +1,7 @@
+module Main where
+
+-- | Foo.
+
+-- | Bar.
+bar :: Int
+bar = 5
diff --git a/data/examples/other/consequetive-pipe-comments.hs b/data/examples/other/consequetive-pipe-comments.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/consequetive-pipe-comments.hs
@@ -0,0 +1,8 @@
+module Main where
+
+-- | Foo.
+
+-- | Bar.
+
+bar :: Int
+bar = 5
diff --git a/data/examples/other/empty-haddock-out.hs b/data/examples/other/empty-haddock-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/empty-haddock-out.hs
@@ -0,0 +1,5 @@
+module Main where
+
+-- |
+foo :: Int
+foo = 5
diff --git a/data/examples/other/empty-haddock.hs b/data/examples/other/empty-haddock.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/empty-haddock.hs
@@ -0,0 +1,6 @@
+module Main where
+
+-- |
+
+foo :: Int
+foo = 5
diff --git a/data/examples/other/following-comment-last-0-out.hs b/data/examples/other/following-comment-last-0-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/following-comment-last-0-out.hs
@@ -0,0 +1,5 @@
+module Main where
+
+-- | Another datatype...
+data D'
+-- ^ ...with two docstrings.
diff --git a/data/examples/other/following-comment-last-0.hs b/data/examples/other/following-comment-last-0.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/following-comment-last-0.hs
@@ -0,0 +1,5 @@
+module Main where
+
+-- | Another datatype...
+data D'
+-- ^ ...with two docstrings.
diff --git a/data/examples/other/following-comment-last-1-out.hs b/data/examples/other/following-comment-last-1-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/following-comment-last-1-out.hs
@@ -0,0 +1,8 @@
+module Main where
+
+-- | Another datatype...
+data D'
+  deriving (Show)
+-- ^ ...with two docstrings.
+
+-- more
diff --git a/data/examples/other/following-comment-last-1.hs b/data/examples/other/following-comment-last-1.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/following-comment-last-1.hs
@@ -0,0 +1,8 @@
+module Main where
+
+-- | Another datatype...
+data D'
+  deriving (Show)
+-- ^ ...with two docstrings.
+
+-- more
diff --git a/data/examples/other/following-comment-last-2-out.hs b/data/examples/other/following-comment-last-2-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/following-comment-last-2-out.hs
@@ -0,0 +1,10 @@
+module Main where
+
+-- | Another datatype...
+data D'
+  deriving (Show)
+-- ^ ...with two docstrings.
+
+-- more
+
+data B
diff --git a/data/examples/other/following-comment-last-2.hs b/data/examples/other/following-comment-last-2.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/following-comment-last-2.hs
@@ -0,0 +1,10 @@
+module Main where
+
+-- | Another datatype...
+data D'
+  deriving (Show)
+-- ^ ...with two docstrings.
+
+-- more
+
+data B
diff --git a/data/examples/other/following-comment-last-3-out.hs b/data/examples/other/following-comment-last-3-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/following-comment-last-3-out.hs
@@ -0,0 +1,6 @@
+module Main where
+
+-- | Another datatype...
+data D'
+-- ^ ...with two docstrings.
+-- even on second line
diff --git a/data/examples/other/following-comment-last-3.hs b/data/examples/other/following-comment-last-3.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/following-comment-last-3.hs
@@ -0,0 +1,6 @@
+module Main where
+
+-- | Another datatype...
+data D'
+-- ^ ...with two docstrings.
+-- even on second line
diff --git a/data/examples/other/merging-comments-out.hs b/data/examples/other/merging-comments-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/merging-comments-out.hs
@@ -0,0 +1,12 @@
+foo xs = baz
+  where
+    bar =
+      catMaybes
+        [ lookup langKey gets, -- 1
+          lookup langKey cookies, -- 2
+          lookupText langKey session -- 3
+        ]
+        ++ xs -- 4
+
+    -- Blah
+    baz = addTwoLetters (id, Set.empty) bar
diff --git a/data/examples/other/merging-comments.hs b/data/examples/other/merging-comments.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/merging-comments.hs
@@ -0,0 +1,9 @@
+foo xs = baz
+  where
+    bar = catMaybes [ lookup langKey gets -- 1
+                    , lookup langKey cookies     -- 2
+                    , lookupText langKey session -- 3
+                    ] ++ xs                    -- 4
+
+    -- Blah
+    baz = addTwoLetters (id, Set.empty) bar
diff --git a/data/examples/other/multiline-comments-reindent-out.hs b/data/examples/other/multiline-comments-reindent-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/multiline-comments-reindent-out.hs
@@ -0,0 +1,6 @@
+{-
+   And so here we have a
+     multiline comment.
+
+   Indeed.
+-}
diff --git a/data/examples/other/multiline-comments-reindent.hs b/data/examples/other/multiline-comments-reindent.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/multiline-comments-reindent.hs
@@ -0,0 +1,6 @@
+              {-
+                 And so here we have a
+                   multiline comment.
+
+                 Indeed.
+              -}
diff --git a/data/examples/other/overly-indented-out.hs b/data/examples/other/overly-indented-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/overly-indented-out.hs
@@ -0,0 +1,11 @@
+tagCloudField ::
+  -- | Destination key
+  String ->
+  -- | Smallest font size, in percent
+  Double ->
+  -- | Biggest font size, in percent
+  Double ->
+  -- | Input tags
+  Tags ->
+  -- | Context
+  Context a
diff --git a/data/examples/other/overly-indented.hs b/data/examples/other/overly-indented.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/overly-indented.hs
@@ -0,0 +1,10 @@
+tagCloudField :: String
+               -- ^ Destination key
+               -> Double
+               -- ^ Smallest font size, in percent
+               -> Double
+               -- ^ Biggest font size, in percent
+               -> Tags
+               -- ^ Input tags
+               -> Context a
+               -- ^ Context
diff --git a/data/examples/other/pragma-no-header-out.hs b/data/examples/other/pragma-no-header-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/pragma-no-header-out.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE ViewPatterns #-}
diff --git a/data/examples/other/pragma-no-header.hs b/data/examples/other/pragma-no-header.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/pragma-no-header.hs
@@ -0,0 +1,3 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGuagE ViewPatterns #-}
+{-# language DataKinds, LambdaCase #-}
diff --git a/data/examples/other/pragma-out.hs b/data/examples/other/pragma-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/pragma-out.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE AllowAmbiguousTypes #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE IncoherentInstances #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ViewPatterns #-}
+{-# OPTIONS_GHC -O2 -H 300 #-}
+{-# OPTIONS_GHC -Wall -Werror #-}
+{-# OPTIONS_HADDOCK prune, show-extensions #-}
+
+-- | Header comment.
+module Foo
+  (
+  )
+where
diff --git a/data/examples/other/pragma.hs b/data/examples/other/pragma.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/pragma.hs
@@ -0,0 +1,13 @@
+-- | Header comment.
+
+{-# LANGUAGE LambdaCase #-}
+{-#LANGuagE ViewPatterns #-}
+{-# LANGUAGE OverloadedStrings#-}
+{-# OPTIONS_GHC -Wall -Werror #-}
+{-# language DataKinds, LambdaCase #-}
+{-# OPTIONS_HADDOCK   prune, show-extensions #-}
+{-# OPTIONS_GHC -O2 -H 300    #-}
+{-# language IncoherentInstances
+           , AllowAmbiguousTypes #-}
+
+module Foo () where
diff --git a/data/examples/other/trailing-whitespace-out.hs b/data/examples/other/trailing-whitespace-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/trailing-whitespace-out.hs
@@ -0,0 +1,7 @@
+-- Here is a comment with trailing whitespace.
+foo = 5
+
+{- Block comment with trailing whitespace.
+   Bo.
+  -}
+bar = 6
diff --git a/data/examples/other/trailing-whitespace.hs b/data/examples/other/trailing-whitespace.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/other/trailing-whitespace.hs
@@ -0,0 +1,7 @@
+-- Here is a comment with trailing whitespace.     
+foo = 5
+
+{- Block comment with trailing whitespace.     
+   Bo.
+  -}
+bar = 6
diff --git a/ormolu.cabal b/ormolu.cabal
new file mode 100644
--- /dev/null
+++ b/ormolu.cabal
@@ -0,0 +1,165 @@
+name:                 ormolu
+version:              0.0.1.0
+cabal-version:        1.18
+tested-with:          GHC==8.6.5
+license:              BSD3
+license-file:         LICENSE.md
+maintainer:           Mark Karpov <mark.karpov@tweag.io>
+homepage:             https://github.com/tweag/ormolu
+bug-reports:          https://github.com/tweag/ormolu/issues
+category:             Development, Formatting
+synopsis:             A formatter for Haskell source code
+build-type:           Simple
+description:          A formatter for Haskell source code.
+extra-doc-files:      CONTRIBUTING.md
+                    , CHANGELOG.md
+                    , DESIGN.md
+                    , README.md
+data-files:           data/examples/declaration/annotation/*.hs
+                    , data/examples/declaration/class/*.hs
+                    , data/examples/declaration/data/*.hs
+                    , data/examples/declaration/data/gadt/*.hs
+                    , data/examples/declaration/default/*.hs
+                    , data/examples/declaration/deriving/*.hs
+                    , data/examples/declaration/foreign/*.hs
+                    , data/examples/declaration/instance/*.hs
+                    , data/examples/declaration/rewrite-rule/*.hs
+                    , data/examples/declaration/role-annotation/*.hs
+                    , data/examples/declaration/signature/complete/*.hs
+                    , data/examples/declaration/signature/fixity/*.hs
+                    , data/examples/declaration/signature/inline/*.hs
+                    , data/examples/declaration/signature/minimal/*.hs
+                    , data/examples/declaration/signature/pattern/*.hs
+                    , data/examples/declaration/signature/set-cost-centre/*.hs
+                    , data/examples/declaration/signature/specialize/*.hs
+                    , data/examples/declaration/signature/type/*.hs
+                    , data/examples/declaration/splice/*.hs
+                    , data/examples/declaration/type-families/closed-type-family/*.hs
+                    , data/examples/declaration/type-families/data-family/*.hs
+                    , data/examples/declaration/type-families/type-family/*.hs
+                    , data/examples/declaration/type-synonyms/*.hs
+                    , data/examples/declaration/type/*.hs
+                    , data/examples/declaration/value/function/*.hs
+                    , data/examples/declaration/value/function/arrow/*.hs
+                    , data/examples/declaration/value/function/comprehension/*.hs
+                    , data/examples/declaration/value/function/do/*.hs
+                    , data/examples/declaration/value/function/infix/*.hs
+                    , data/examples/declaration/value/function/pattern/*.hs
+                    , data/examples/declaration/value/other/*.hs
+                    , data/examples/declaration/value/pattern-synonyms/*.hs
+                    , data/examples/declaration/warning/*.hs
+                    , data/examples/import/*.hs
+                    , data/examples/module-header/*.hs
+                    , data/examples/other/*.hs
+
+source-repository head
+  type:               git
+  location:           https://github.com/tweag/ormolu.git
+
+flag dev
+  description:        Turn on development settings.
+  manual:             True
+  default:            False
+
+library
+  hs-source-dirs:     src
+  build-depends:      base           >= 4.12 && < 5.0
+                    , bytestring     >= 0.2 && < 0.11
+                    , containers     >= 0.5 && < 0.7
+                    , dlist          >= 0.8 && < 0.9
+                    , exceptions     >= 0.6 && < 0.11
+                    , ghc            == 8.6.5
+                    , ghc-boot-th    == 8.6.5
+                    , ghc-paths      >= 0.1 && < 0.2
+                    , mtl            >= 2.0 && < 3.0
+                    , syb            >= 0.7 && < 0.8
+                    , text           >= 0.2 && < 1.3
+  exposed-modules:    Ormolu
+                    , Ormolu.Config
+                    , Ormolu.Diff
+                    , Ormolu.Exception
+                    , Ormolu.Imports
+                    , Ormolu.Parser
+                    , Ormolu.Parser.Anns
+                    , Ormolu.Parser.CommentStream
+                    , Ormolu.Parser.Pragma
+                    , Ormolu.Parser.Result
+                    , Ormolu.Printer
+                    , Ormolu.Printer.Combinators
+                    , Ormolu.Printer.Comments
+                    , Ormolu.Printer.Internal
+                    , Ormolu.Printer.Meat.Common
+                    , Ormolu.Printer.Meat.Declaration
+                    , Ormolu.Printer.Meat.Declaration.Annotation
+                    , Ormolu.Printer.Meat.Declaration.Class
+                    , Ormolu.Printer.Meat.Declaration.Data
+                    , Ormolu.Printer.Meat.Declaration.Default
+                    , Ormolu.Printer.Meat.Declaration.Foreign
+                    , Ormolu.Printer.Meat.Declaration.Instance
+                    , Ormolu.Printer.Meat.Declaration.RoleAnnotation
+                    , Ormolu.Printer.Meat.Declaration.Rule
+                    , Ormolu.Printer.Meat.Declaration.Signature
+                    , Ormolu.Printer.Meat.Declaration.Splice
+                    , Ormolu.Printer.Meat.Declaration.Type
+                    , Ormolu.Printer.Meat.Declaration.TypeFamily
+                    , Ormolu.Printer.Meat.Declaration.Value
+                    , Ormolu.Printer.Meat.Declaration.Warning
+                    , Ormolu.Printer.Meat.ImportExport
+                    , Ormolu.Printer.Meat.Module
+                    , Ormolu.Printer.Meat.Pragma
+                    , Ormolu.Printer.Meat.Type
+                    , Ormolu.Printer.Operators
+                    , Ormolu.Printer.SpanStream
+                    , Ormolu.Utils
+  if flag(dev)
+    ghc-options:      -Wall -Werror -Wcompat
+                      -Wincomplete-record-updates
+                      -Wincomplete-uni-patterns
+                      -Wnoncanonical-monad-instances
+                      -Wnoncanonical-monadfail-instances
+  else
+    ghc-options:      -O2 -Wall
+  default-language:   Haskell2010
+
+test-suite tests
+  main-is:            Spec.hs
+  hs-source-dirs:     tests
+  type:               exitcode-stdio-1.0
+  build-depends:      base           >= 4.12 && < 5.0
+                    , containers     >= 0.5 && < 0.7
+                    , filepath       >= 1.2 && < 1.5
+                    , hspec          >= 2.0 && < 3.0
+                    , ormolu
+                    , path           >= 0.6 && < 0.7
+                    , path-io        >= 1.4.2 && < 2.0
+                    , text           >= 0.2 && < 1.3
+  build-tools:        hspec-discover >= 2.0 && < 3.0
+  other-modules:
+                      Ormolu.Parser.PragmaSpec
+                    , Ormolu.PrinterSpec
+
+  if flag(dev)
+    ghc-options:      -Wall -Werror
+  else
+    ghc-options:      -O2 -Wall
+  default-language:   Haskell2010
+
+executable ormolu
+  main-is:            Main.hs
+  hs-source-dirs:     app
+  build-depends:      base           >= 4.12 && < 5.0
+                    , ghc            == 8.6.5
+                    , gitrev         >= 1.3 && < 1.4
+                    , optparse-applicative >= 0.14 && < 0.15
+                    , ormolu
+                    , text           >= 0.2 && < 1.3
+  other-modules:      Paths_ormolu
+  if flag(dev)
+    ghc-options:      -Wall -Werror -Wcompat
+                      -Wincomplete-record-updates
+                      -Wincomplete-uni-patterns
+                      -Wnoncanonical-monad-instances
+                      -Wnoncanonical-monadfail-instances
+  else
+    ghc-options:      -O2 -Wall
+  default-language:   Haskell2010
diff --git a/src/Ormolu.hs b/src/Ormolu.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu.hs
@@ -0,0 +1,147 @@
+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | A formatter for Haskell source code.
+module Ormolu
+  ( ormolu,
+    ormoluFile,
+    ormoluStdin,
+    Config (..),
+    defaultConfig,
+    DynOption (..),
+    OrmoluException (..),
+    withPrettyOrmoluExceptions,
+  )
+where
+
+import qualified CmdLineParser as GHC
+import Control.Exception
+import Control.Monad
+import Control.Monad.IO.Class (MonadIO (..))
+import Data.Text (Text)
+import qualified Data.Text as T
+import Debug.Trace
+import Ormolu.Config
+import Ormolu.Diff
+import Ormolu.Exception
+import Ormolu.Parser
+import Ormolu.Parser.Result
+import Ormolu.Printer
+import Ormolu.Utils (showOutputable)
+import qualified SrcLoc as GHC
+import System.IO (hGetContents, stdin)
+
+-- | Format a 'String', return formatted version as 'Text'.
+--
+-- The function
+--
+--     * Takes 'String' because that's what GHC parser accepts.
+--     * Needs 'IO' because some functions from GHC that are necessary to
+--       setup parsing context require 'IO'. There should be no visible
+--       side-effects though.
+--     * Takes file name just to use it in parse error messages.
+--     * Throws 'OrmoluException'.
+ormolu ::
+  MonadIO m =>
+  -- | Ormolu configuration
+  Config ->
+  -- | Location of source file
+  FilePath ->
+  -- | Input to format
+  String ->
+  m Text
+ormolu cfg path str = do
+  (ws, result0) <-
+    parseModule' cfg OrmoluParsingFailed path str
+  when (cfgDebug cfg) $ do
+    traceM "warnings:\n"
+    traceM (concatMap showWarn ws)
+    traceM (prettyPrintParseResult result0)
+  -- NOTE We're forcing 'txt' here because otherwise errors (such as
+  -- messages about not-yet-supported functionality) will be thrown later
+  -- when we try to parse the rendered code back, inside of GHC monad
+  -- wrapper which will lead to error messages presenting the exceptions as
+  -- GHC bugs.
+  let !txt = printModule result0
+  when (not (cfgUnsafe cfg) || cfgCheckIdempotency cfg) $ do
+    let pathRendered = path ++ "<rendered>"
+    -- Parse the result of pretty-printing again and make sure that AST
+    -- is the same as AST of original snippet module span positions.
+    (_, result1) <-
+      parseModule'
+        cfg
+        OrmoluOutputParsingFailed
+        pathRendered
+        (T.unpack txt)
+    unless (cfgUnsafe cfg) $
+      case diffParseResult result0 result1 of
+        Same -> return ()
+        Different ss -> liftIO $ throwIO (OrmoluASTDiffers path ss)
+    -- Try re-formatting the formatted result to check if we get exactly
+    -- the same output.
+    when (cfgCheckIdempotency cfg) $
+      let txt2 = printModule result1
+       in case diffText txt txt2 pathRendered of
+            Nothing -> return ()
+            Just (loc, l, r) ->
+              liftIO $
+                throwIO (OrmoluNonIdempotentOutput loc l r)
+  return txt
+
+-- | Load a file and format it. The file stays intact and the rendered
+-- version is returned as 'Text'.
+--
+-- > ormoluFile cfg path =
+-- >   liftIO (readFile path) >>= ormolu cfg path
+ormoluFile ::
+  MonadIO m =>
+  -- | Ormolu configuration
+  Config ->
+  -- | Location of source file
+  FilePath ->
+  -- | Resulting rendition
+  m Text
+ormoluFile cfg path =
+  liftIO (readFile path) >>= ormolu cfg path
+
+-- | Read input from stdin and format it.
+--
+-- > ormoluStdin cfg =
+-- >   liftIO (hGetContents stdin) >>= ormolu cfg "<stdin>"
+ormoluStdin ::
+  MonadIO m =>
+  -- | Ormolu configuration
+  Config ->
+  -- | Resulting rendition
+  m Text
+ormoluStdin cfg =
+  liftIO (hGetContents stdin) >>= ormolu cfg "<stdin>"
+
+----------------------------------------------------------------------------
+-- Helpers
+
+-- | A wrapper around 'parseModule'.
+parseModule' ::
+  MonadIO m =>
+  -- | Ormolu configuration
+  Config ->
+  -- | How to obtain 'OrmoluException' to throw when parsing fails
+  (GHC.SrcSpan -> String -> OrmoluException) ->
+  -- | File name to use in errors
+  FilePath ->
+  -- | Actual input for the parser
+  String ->
+  m ([GHC.Warn], ParseResult)
+parseModule' cfg mkException path str = do
+  (ws, r) <- parseModule cfg path str
+  case r of
+    Left (spn, err) -> liftIO $ throwIO (mkException spn err)
+    Right x -> return (ws, x)
+
+-- | Pretty-print a 'GHC.Warn'.
+showWarn :: GHC.Warn -> String
+showWarn (GHC.Warn reason l) =
+  unlines
+    [ showOutputable reason,
+      showOutputable l
+    ]
diff --git a/src/Ormolu/Config.hs b/src/Ormolu/Config.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Config.hs
@@ -0,0 +1,53 @@
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Configuration options used by the tool.
+module Ormolu.Config
+  ( Config (..),
+    defaultConfig,
+    DynOption (..),
+    dynOptionToLocatedStr,
+  )
+where
+
+import qualified SrcLoc as GHC
+
+-- | Ormolu configuration.
+data Config
+  = Config
+      { -- | Dynamic options to pass to GHC parser
+        cfgDynOptions :: ![DynOption],
+        -- | Do formatting faster but without automatic detection of defects
+        cfgUnsafe :: !Bool,
+        -- | Output information useful for debugging
+        cfgDebug :: !Bool,
+        -- | Do not fail if CPP pragma is present (still doesn't handle CPP but
+        -- useful for formatting of files that enable the extension without
+        -- actually containing CPP macros)
+        cfgTolerateCpp :: !Bool,
+        -- | Checks if re-formatting the result is idempotent.
+        cfgCheckIdempotency :: !Bool
+      }
+  deriving (Eq, Show)
+
+-- | Default 'Config'.
+defaultConfig :: Config
+defaultConfig = Config
+  { cfgDynOptions = [],
+    cfgUnsafe = False,
+    cfgDebug = False,
+    cfgTolerateCpp = False,
+    cfgCheckIdempotency = False
+  }
+
+-- | A wrapper for dynamic options.
+newtype DynOption
+  = DynOption
+      { unDynOption :: String
+      }
+  deriving (Eq, Ord, Show)
+
+-- | Convert 'DynOption' to @'GHC.Located' 'String'@.
+dynOptionToLocatedStr :: DynOption -> GHC.Located String
+dynOptionToLocatedStr (DynOption o) = GHC.L GHC.noSrcSpan o
diff --git a/src/Ormolu/Diff.hs b/src/Ormolu/Diff.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Diff.hs
@@ -0,0 +1,151 @@
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Diffing GHC ASTs modulo span positions.
+module Ormolu.Diff
+  ( Diff (..),
+    diffParseResult,
+    diffText,
+  )
+where
+
+import BasicTypes (SourceText)
+import Data.ByteString (ByteString)
+import Data.Generics
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified FastString as GHC
+import GHC
+import Ormolu.Imports (sortImports)
+import Ormolu.Parser.Result
+import Ormolu.Utils
+import qualified SrcLoc as GHC
+
+-- | Result of comparing two 'ParseResult's.
+data Diff
+  = -- | Two parse results are the same
+    Same
+  | -- | Two parse results differ
+    Different [SrcSpan]
+
+instance Semigroup Diff where
+  Same <> a = a
+  a <> Same = a
+  Different xs <> Different ys = Different (xs ++ ys)
+
+instance Monoid Diff where
+  mempty = Same
+
+-- | Return 'Diff' of two 'ParseResult's.
+diffParseResult :: ParseResult -> ParseResult -> Diff
+diffParseResult
+  ParseResult
+    { prCommentStream = cstream0,
+      prParsedSource = ps0
+    }
+  ParseResult
+    { prCommentStream = cstream1,
+      prParsedSource = ps1
+    } =
+    matchIgnoringSrcSpans cstream0 cstream1
+      <> matchIgnoringSrcSpans ps0 ps1
+
+-- | Compare two values for equality disregarding differences in 'SrcSpan's
+-- and the ordering of import lists.
+matchIgnoringSrcSpans :: Data a => a -> a -> Diff
+matchIgnoringSrcSpans = genericQuery
+  where
+    genericQuery :: GenericQ (GenericQ Diff)
+    genericQuery x y
+      -- NOTE 'ByteString' implement 'Data' instance manually and does not
+      -- implement 'toConstr', so we have to deal with it in a special way.
+      | Just x' <- cast x,
+        Just y' <- cast y =
+        if x' == (y' :: ByteString)
+          then Same
+          else Different []
+      | typeOf x == typeOf y,
+        toConstr x == toConstr y =
+        mconcat $
+          gzipWithQ
+            ( genericQuery
+                `extQ` srcSpanEq
+                `extQ` hsModuleEq
+                `extQ` sourceTextEq
+                `extQ` hsDocStringEq
+                `ext2Q` forLocated
+            )
+            x
+            y
+      | otherwise = Different []
+    srcSpanEq :: SrcSpan -> GenericQ Diff
+    srcSpanEq _ _ = Same
+    hsModuleEq :: HsModule GhcPs -> GenericQ Diff
+    hsModuleEq hs0 hs1' =
+      case cast hs1' :: Maybe (HsModule GhcPs) of
+        Nothing -> Different []
+        Just hs1 ->
+          matchIgnoringSrcSpans
+            hs0 {hsmodImports = sortImports (hsmodImports hs0)}
+            hs1 {hsmodImports = sortImports (hsmodImports hs1)}
+    sourceTextEq :: SourceText -> GenericQ Diff
+    sourceTextEq _ _ = Same
+    hsDocStringEq :: HsDocString -> GenericQ Diff
+    hsDocStringEq str0 str1' =
+      case cast str1' :: Maybe HsDocString of
+        Nothing -> Different []
+        Just str1 ->
+          if splitDocString str0 == splitDocString str1
+            then Same
+            else Different []
+    forLocated ::
+      (Data e0, Data e1) =>
+      GenLocated e0 e1 ->
+      GenericQ Diff
+    forLocated x@(L mspn _) y =
+      maybe id appendSpan (cast mspn) (genericQuery x y)
+    appendSpan :: SrcSpan -> Diff -> Diff
+    appendSpan s (Different ss) | fresh && helpful = Different (s : ss)
+      where
+        fresh = not $ any (flip isSubspanOf s) ss
+        helpful = isGoodSrcSpan s
+    appendSpan _ d = d
+
+-- | Diff two texts and return the location they start to differ, alongside
+-- with excerpts around that location.
+diffText ::
+  -- | Text before
+  Text ->
+  -- | Text after
+  Text ->
+  -- | Path to use to construct 'GHC.RealSrcLoc'
+  FilePath ->
+  Maybe (GHC.RealSrcLoc, Text, Text)
+diffText left right fp =
+  case go (0, 0, 0) left right of
+    Nothing -> Nothing
+    Just (row, col, loc) ->
+      Just
+        ( GHC.mkRealSrcLoc (GHC.mkFastString fp) row col,
+          getSpan loc left,
+          getSpan loc right
+        )
+  where
+    go (row, col, loc) t1 t2 =
+      case (T.uncons t1, T.uncons t2) of
+        -- both text empty, all good
+        (Nothing, Nothing) ->
+          Nothing
+        -- first chars are the same, adjust position and recurse
+        (Just (c1, r1), Just (c2, r2))
+          | c1 == c2 ->
+            let (row', col', loc') =
+                  if c1 == '\n'
+                    then (row + 1, 0, loc + 1)
+                    else (row, col + 1, loc + 1)
+             in go (row', col', loc') r1 r2
+        -- something is different, return the position
+        _ ->
+          Just (row, col, loc)
+    getSpan loc = T.take 20 . T.drop (loc - 10)
diff --git a/src/Ormolu/Exception.hs b/src/Ormolu/Exception.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Exception.hs
@@ -0,0 +1,94 @@
+{-# LANGUAGE LambdaCase #-}
+
+-- | 'OrmoluException' type and surrounding definitions.
+module Ormolu.Exception
+  ( OrmoluException (..),
+    withPrettyOrmoluExceptions,
+  )
+where
+
+import Control.Exception
+import Data.Text (Text)
+import qualified GHC
+import Ormolu.Utils (showOutputable)
+import qualified Outputable as GHC
+import System.Exit (ExitCode (..), exitWith)
+import System.IO
+
+-- | Ormolu exception representing all cases when Ormolu can fail.
+data OrmoluException
+  = -- | Ormolu does not work with source files that use CPP
+    OrmoluCppEnabled FilePath
+  | -- | Parsing of original source code failed
+    OrmoluParsingFailed GHC.SrcSpan String
+  | -- | Parsing of formatted source code failed
+    OrmoluOutputParsingFailed GHC.SrcSpan String
+  | -- | Original and resulting ASTs differ
+    OrmoluASTDiffers FilePath [GHC.SrcSpan]
+  | -- | Formatted source code is not idempotent
+    OrmoluNonIdempotentOutput GHC.RealSrcLoc Text Text
+  deriving (Eq, Show)
+
+instance Exception OrmoluException where
+  displayException = \case
+    OrmoluCppEnabled path ->
+      unlines
+        [ "CPP is not supported:",
+          withIndent path
+        ]
+    OrmoluParsingFailed s e ->
+      showParsingErr "Parsing of source code failed:" s [e]
+    OrmoluOutputParsingFailed s e ->
+      showParsingErr "Parsing of formatted code failed:" s [e]
+        ++ "Please, consider reporting the bug.\n"
+    OrmoluASTDiffers path ss ->
+      unlines $
+        [ "AST of input and AST of formatted code differ."
+        ]
+          ++ ( fmap withIndent $ case fmap (\s -> "at " ++ showOutputable s) ss of
+                 [] -> ["in " ++ path]
+                 xs -> xs
+             )
+          ++ ["Please, consider reporting the bug."]
+    OrmoluNonIdempotentOutput loc left right ->
+      showParsingErr
+        "Formatting is not idempotent:"
+        loc
+        ["before: " ++ show left, "after:  " ++ show right]
+        ++ "Please, consider reporting the bug.\n"
+
+-- | Inside this wrapper 'OrmoluException' will be caught and displayed
+-- nicely using 'displayException'.
+withPrettyOrmoluExceptions ::
+  -- | Action that may throw the exception
+  IO a ->
+  IO a
+withPrettyOrmoluExceptions m = m `catch` h
+  where
+    h :: OrmoluException -> IO a
+    h e = do
+      hPutStrLn stderr (displayException e)
+      exitWith . ExitFailure $
+        case e of
+          -- Error code 1 is for `error` or `notImplemented`
+          OrmoluCppEnabled _ -> 2
+          OrmoluParsingFailed _ _ -> 3
+          OrmoluOutputParsingFailed _ _ -> 4
+          OrmoluASTDiffers _ _ -> 5
+          OrmoluNonIdempotentOutput _ _ _ -> 6
+
+----------------------------------------------------------------------------
+-- Helpers
+
+-- | Show a parse error.
+showParsingErr :: GHC.Outputable a => String -> a -> [String] -> String
+showParsingErr msg spn err =
+  unlines $
+    [ msg,
+      withIndent (showOutputable spn)
+    ]
+      ++ map withIndent err
+
+-- | Indent with 2 spaces for readability.
+withIndent :: String -> String
+withIndent txt = "  " ++ txt
diff --git a/src/Ormolu/Imports.hs b/src/Ormolu/Imports.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Imports.hs
@@ -0,0 +1,81 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE RankNTypes #-}
+
+-- | Manipulations on import lists.
+module Ormolu.Imports
+  ( sortImports,
+  )
+where
+
+import Data.Bifunctor
+import Data.Function (on)
+import Data.Generics (gcompare)
+import Data.List (sortBy)
+import GHC hiding (GhcPs, IE)
+import HsExtension
+import HsImpExp (IE (..))
+import Ormolu.Utils (notImplemented)
+
+-- | Sort imports by module name. This also sorts explicit import lists for
+-- each declaration.
+sortImports :: [LImportDecl GhcPs] -> [LImportDecl GhcPs]
+sortImports = sortBy compareIdecl . fmap (fmap sortImportLists)
+  where
+    sortImportLists :: ImportDecl GhcPs -> ImportDecl GhcPs
+    sortImportLists decl =
+      decl
+        { ideclHiding = second (fmap sortLies) <$> ideclHiding decl
+        }
+
+-- | Compare two @'LImportDecl' 'GhcPs'@ things.
+compareIdecl :: LImportDecl GhcPs -> LImportDecl GhcPs -> Ordering
+compareIdecl (L _ m0) (L _ m1) =
+  case (isPrelude n0, isPrelude n1) of
+    (False, False) -> n0 `compare` n1
+    (True, False) -> GT
+    (False, True) -> LT
+    (True, True) -> m0 `gcompare` m1
+  where
+    n0 = unLoc (ideclName m0)
+    n1 = unLoc (ideclName m1)
+    isPrelude = (== "Prelude") . moduleNameString
+
+-- | Sort located import or export.
+sortLies :: [LIE GhcPs] -> [LIE GhcPs]
+sortLies = sortBy (compareIE `on` unLoc) . fmap (fmap sortThings)
+
+-- | Sort imports\/exports inside of 'IEThingWith'.
+sortThings :: IE GhcPs -> IE GhcPs
+sortThings = \case
+  IEThingWith NoExt x w xs fl ->
+    IEThingWith NoExt x w (sortBy (compareIewn `on` unLoc) xs) fl
+  other -> other
+
+-- | Compare two located imports or exports.
+compareIE :: IE GhcPs -> IE GhcPs -> Ordering
+compareIE = compareIewn `on` getIewn
+
+-- | Project @'IEWrappedName' 'RdrName'@ from @'IE' 'GhcPs'@.
+getIewn :: IE GhcPs -> IEWrappedName RdrName
+getIewn = \case
+  IEVar NoExt x -> unLoc x
+  IEThingAbs NoExt x -> unLoc x
+  IEThingAll NoExt x -> unLoc x
+  IEThingWith NoExt x _ _ _ -> unLoc x
+  IEModuleContents NoExt _ -> notImplemented "IEModuleContents"
+  IEGroup NoExt _ _ -> notImplemented "IEGroup"
+  IEDoc NoExt _ -> notImplemented "IEDoc"
+  IEDocNamed NoExt _ -> notImplemented "IEDocNamed"
+  XIE NoExt -> notImplemented "XIE"
+
+-- | Compare two @'IEWrapppedName' 'RdrName'@ things.
+compareIewn :: IEWrappedName RdrName -> IEWrappedName RdrName -> Ordering
+compareIewn (IEName x) (IEName y) = unLoc x `compare` unLoc y
+compareIewn (IEName _) (IEPattern _) = LT
+compareIewn (IEName _) (IEType _) = LT
+compareIewn (IEPattern _) (IEName _) = GT
+compareIewn (IEPattern x) (IEPattern y) = unLoc x `compare` unLoc y
+compareIewn (IEPattern _) (IEType _) = LT
+compareIewn (IEType _) (IEName _) = GT
+compareIewn (IEType _) (IEPattern _) = GT
+compareIewn (IEType x) (IEType y) = unLoc x `compare` unLoc y
diff --git a/src/Ormolu/Parser.hs b/src/Ormolu/Parser.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Parser.hs
@@ -0,0 +1,201 @@
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE StandaloneDeriving #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+
+-- | Parser for Haskell source code.
+module Ormolu.Parser
+  ( parseModule,
+    manualExts,
+  )
+where
+
+import qualified CmdLineParser as GHC
+import Control.Exception
+import Control.Monad
+import Control.Monad.IO.Class
+import Data.List ((\\), foldl', isPrefixOf)
+import Data.Maybe (catMaybes)
+import qualified DynFlags as GHC
+import qualified FastString as GHC
+import GHC hiding (IE, parseModule, parser)
+import GHC.LanguageExtensions.Type (Extension (..))
+import GHC.Paths (libdir)
+import qualified HeaderInfo as GHC
+import qualified Lexer as GHC
+import Ormolu.Config
+import Ormolu.Exception
+import Ormolu.Parser.Anns
+import Ormolu.Parser.CommentStream
+import Ormolu.Parser.Result
+import qualified Outputable as GHC
+import qualified Parser as GHC
+import qualified SrcLoc as GHC
+import qualified StringBuffer as GHC
+
+-- | Parse a complete module from string.
+parseModule ::
+  MonadIO m =>
+  -- | Ormolu configuration
+  Config ->
+  -- | File name (only for source location annotations)
+  FilePath ->
+  -- | Input for parser
+  String ->
+  m
+    ( [GHC.Warn],
+      Either (SrcSpan, String) ParseResult
+    )
+parseModule Config {..} path input' = liftIO $ do
+  let (input, extraComments) = stripLinePragmas path input'
+  (ws, dynFlags) <- ghcWrapper $ do
+    dynFlags0 <- initDynFlagsPure path input
+    (dynFlags1, _, ws) <-
+      GHC.parseDynamicFilePragma
+        dynFlags0
+        (dynOptionToLocatedStr <$> cfgDynOptions)
+    return (ws, GHC.setGeneralFlag' GHC.Opt_Haddock dynFlags1)
+  -- NOTE It's better to throw this outside of 'ghcWrapper' because
+  -- otherwise the exception will be wrapped as a GHC panic, which we don't
+  -- want.
+  when (GHC.xopt Cpp dynFlags && not cfgTolerateCpp) $
+    throwIO (OrmoluCppEnabled path)
+  let r = case runParser GHC.parseModule dynFlags path input of
+        GHC.PFailed _ ss m ->
+          Left (ss, GHC.showSDoc dynFlags m)
+        GHC.POk pstate pmod ->
+          let (comments, exts) = mkCommentStream extraComments pstate
+           in Right ParseResult
+                { prParsedSource = pmod,
+                  prAnns = mkAnns pstate,
+                  prCommentStream = comments,
+                  prExtensions = exts
+                }
+  return (ws, r)
+
+-- | Extensions that are not enabled automatically and should be activated
+-- by user.
+manualExts :: [Extension]
+manualExts =
+  [ Arrows, -- steals proc
+    Cpp, -- forbidden
+    BangPatterns, -- makes certain patterns with ! fail
+    PatternSynonyms, -- steals the pattern keyword
+    RecursiveDo, -- steals the rec keyword
+    StaticPointers, -- steals static keyword
+    TransformListComp, -- steals the group keyword
+    UnboxedTuples, -- breaks (#) lens operator
+    MagicHash, -- screws {-# these things #-}
+    TypeApplications, -- steals (@) operator on some cases
+    AlternativeLayoutRule,
+    AlternativeLayoutRuleTransitional,
+    MonadComprehensions,
+    UnboxedSums,
+    UnicodeSyntax, -- gives special meanings to operators like (→)
+    TemplateHaskellQuotes -- enables TH subset of quasi-quotes, this
+    -- apparently interferes with QuasiQuotes in
+    -- weird ways
+  ]
+
+----------------------------------------------------------------------------
+-- Helpers (taken from ghc-exactprint)
+
+-- | Requires GhcMonad constraint because there is no pure variant of
+-- 'parseDynamicFilePragma'. Yet, in constrast to 'initDynFlags', it does
+-- not (try to) read the file at filepath, but solely depends on the module
+-- source in the input string.
+--
+-- Passes "-hide-all-packages" to the GHC API to prevent parsing of package
+-- environment files. However this only works if there is no invocation of
+-- 'setSessionDynFlags' before calling 'initDynFlagsPure'. See GHC tickets
+-- #15513, #15541.
+initDynFlagsPure ::
+  GHC.GhcMonad m =>
+  -- | Module path
+  FilePath ->
+  -- | Module contents
+  String ->
+  -- | Dynamic flags for that module
+  m GHC.DynFlags
+initDynFlagsPure fp input = do
+  -- I was told we could get away with using the 'unsafeGlobalDynFlags'. as
+  -- long as 'parseDynamicFilePragma' is impure there seems to be no reason
+  -- to use it.
+  dflags0 <- setDefaultExts <$> GHC.getSessionDynFlags
+  let tokens = GHC.getOptions dflags0 (GHC.stringToStringBuffer input) fp
+  (dflags1, _, _) <- GHC.parseDynamicFilePragma dflags0 tokens
+  -- Turn this on last to avoid T10942
+  let dflags2 = dflags1 `GHC.gopt_set` GHC.Opt_KeepRawTokenStream
+  -- Prevent parsing of .ghc.environment.* "package environment files"
+  (dflags3, _, _) <-
+    GHC.parseDynamicFlagsCmdLine
+      dflags2
+      [GHC.noLoc "-hide-all-packages"]
+  _ <- GHC.setSessionDynFlags dflags3
+  return dflags3
+
+-- | Default runner of 'GHC.Ghc' action in 'IO'.
+ghcWrapper :: GHC.Ghc a -> IO a
+ghcWrapper act =
+  let GHC.FlushOut flushOut = GHC.defaultFlushOut
+   in GHC.runGhc (Just libdir) act
+        `finally` flushOut
+
+-- | Run a 'GHC.P' computation.
+runParser ::
+  -- | Computation to run
+  GHC.P a ->
+  -- | Dynamic flags
+  GHC.DynFlags ->
+  -- | Module path
+  FilePath ->
+  -- | Module contents
+  String ->
+  -- | Parse result
+  GHC.ParseResult a
+runParser parser flags filename input = GHC.unP parser parseState
+  where
+    location = GHC.mkRealSrcLoc (GHC.mkFastString filename) 1 1
+    buffer = GHC.stringToStringBuffer input
+    parseState = GHC.mkPState flags buffer location
+
+-- | Remove GHC style line pragams (@{-# LINE .. #-}@) and convert them into
+-- comments.
+stripLinePragmas :: FilePath -> String -> (String, [Located String])
+stripLinePragmas path = unlines' . unzip . findLines path . lines
+  where
+    unlines' (a, b) = (unlines a, catMaybes b)
+
+findLines :: FilePath -> [String] -> [(String, Maybe (Located String))]
+findLines path = zipWith (checkLine path) [1 ..]
+
+checkLine :: FilePath -> Int -> String -> (String, Maybe (Located String))
+checkLine path line s
+  | "{-# LINE" `isPrefixOf` s =
+    let (pragma, res) = getPragma s
+        size = length pragma
+        ss = mkSrcSpan (mkSrcLoc' 1) (mkSrcLoc' (size + 1))
+     in (res, Just $ L ss pragma)
+  | "#!" `isPrefixOf` s =
+    let ss = mkSrcSpan (mkSrcLoc' 1) (mkSrcLoc' (length s))
+     in ("", Just $ L ss s)
+  | otherwise = (s, Nothing)
+  where
+    mkSrcLoc' = mkSrcLoc (GHC.mkFastString path) line
+
+getPragma :: String -> (String, String)
+getPragma [] = error "Ormolu.Parser.getPragma: input must not be empty"
+getPragma s@(x : xs)
+  | "#-}" `isPrefixOf` s = ("#-}", "   " ++ drop 3 s)
+  | otherwise =
+    let (prag, remline) = getPragma xs
+     in (x : prag, ' ' : remline)
+
+-- | Enable all language extensions that we think should be enabled by
+-- default for ease of use.
+setDefaultExts :: DynFlags -> DynFlags
+setDefaultExts flags = foldl' GHC.xopt_set flags autoExts
+  where
+    autoExts = allExts \\ manualExts
+    allExts = [minBound .. maxBound]
+
+deriving instance Bounded Extension
diff --git a/src/Ormolu/Parser/Anns.hs b/src/Ormolu/Parser/Anns.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Parser/Anns.hs
@@ -0,0 +1,46 @@
+-- | Ormolu-specific representation of GHC annotations.
+module Ormolu.Parser.Anns
+  ( Anns (..),
+    emptyAnns,
+    mkAnns,
+    lookupAnns,
+  )
+where
+
+import Data.Map.Strict (Map)
+import qualified Data.Map.Strict as M
+import Data.Maybe (mapMaybe)
+import qualified GHC
+import qualified Lexer as GHC
+import SrcLoc
+
+-- | Ormolu-specific representation of GHC annotations.
+newtype Anns = Anns (Map RealSrcSpan [GHC.AnnKeywordId])
+  deriving (Eq)
+
+-- | Empty 'Anns'.
+emptyAnns :: Anns
+emptyAnns = Anns M.empty
+
+-- | Create 'Anns' from 'GHC.PState'.
+mkAnns ::
+  GHC.PState ->
+  Anns
+mkAnns pstate =
+  Anns $
+    M.fromListWith (++) (mapMaybe f (GHC.annotations pstate))
+  where
+    f ((spn, kid), _) =
+      case spn of
+        RealSrcSpan rspn -> Just (rspn, [kid])
+        UnhelpfulSpan _ -> Nothing
+
+-- | Lookup 'GHC.AnnKeywordId's corresponding to a given 'SrcSpan'.
+lookupAnns ::
+  -- | Span to lookup with
+  SrcSpan ->
+  -- | Collection of annotations
+  Anns ->
+  [GHC.AnnKeywordId]
+lookupAnns (RealSrcSpan rspn) (Anns m) = M.findWithDefault [] rspn m
+lookupAnns (UnhelpfulSpan _) _ = []
diff --git a/src/Ormolu/Parser/CommentStream.hs b/src/Ormolu/Parser/CommentStream.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Parser/CommentStream.hs
@@ -0,0 +1,138 @@
+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE TupleSections #-}
+
+-- | Functions for working with comment stream.
+module Ormolu.Parser.CommentStream
+  ( CommentStream (..),
+    Comment (..),
+    mkCommentStream,
+    isPrevHaddock,
+    isMultilineComment,
+    showCommentStream,
+  )
+where
+
+import Data.Char (isSpace)
+import Data.Data (Data)
+import Data.Either (partitionEithers)
+import Data.List (dropWhileEnd, isPrefixOf, sortOn)
+import Data.List.NonEmpty (NonEmpty (..))
+import qualified Data.List.NonEmpty as NE
+import Data.Maybe (mapMaybe)
+import qualified GHC
+import qualified Lexer as GHC
+import Ormolu.Parser.Pragma
+import Ormolu.Utils (showOutputable)
+import SrcLoc
+
+-- | A stream of 'RealLocated' 'Comment's in ascending order with respect to
+-- beginning of corresponding spans.
+newtype CommentStream = CommentStream [RealLocated Comment]
+  deriving (Eq, Data, Semigroup, Monoid)
+
+-- | A wrapper for a single comment. The 'NonEmpty' list inside contains
+-- lines of multiline comment @{- … -}@ or just single item\/line otherwise.
+newtype Comment = Comment (NonEmpty String)
+  deriving (Eq, Show, Data)
+
+-- | Create 'CommentStream' from 'GHC.PState'. We also create a 'Set' of
+-- extensions here, which is not sorted in any way. The pragma comment are
+-- removed from the 'CommentStream'.
+mkCommentStream ::
+  -- | Extra comments to include
+  [Located String] ->
+  -- | Parser state to use for comment extraction
+  GHC.PState ->
+  -- | Comment stream and a set of extracted pragmas
+  (CommentStream, [Pragma])
+mkCommentStream extraComments pstate =
+  ( CommentStream $
+      -- NOTE It's easier to normalize pragmas right when we construct comment
+      -- streams. Because this way we need to do it only once and when we
+      -- perform checking later they'll automatically match.
+      mkComment <$> sortOn (realSrcSpanStart . getLoc) comments,
+    pragmas
+  )
+  where
+    (comments, pragmas) = partitionEithers (partitionComments <$> rawComments)
+    rawComments =
+      mapMaybe toRealSpan $
+        extraComments
+          ++ mapMaybe (liftMaybe . fmap unAnnotationComment) (GHC.comment_q pstate)
+          ++ concatMap
+            (mapMaybe (liftMaybe . fmap unAnnotationComment) . snd)
+            (GHC.annotations_comments pstate)
+
+-- | Test whether a 'Comment' looks like a Haddock following a definition,
+-- i.e. something starting with @-- ^@.
+isPrevHaddock :: Comment -> Bool
+isPrevHaddock (Comment (x :| _)) = "-- ^" `isPrefixOf` x
+
+-- | Is this comment multiline-style?
+isMultilineComment :: Comment -> Bool
+isMultilineComment (Comment (x :| _)) = "{-" `isPrefixOf` x
+
+-- | Pretty-print a 'CommentStream'.
+showCommentStream :: CommentStream -> String
+showCommentStream (CommentStream xs) =
+  unlines $
+    showComment <$> xs
+  where
+    showComment (GHC.L l str) = showOutputable l ++ " " ++ show str
+
+----------------------------------------------------------------------------
+-- Helpers
+
+-- | Normalize comment string. Sometimes one multi-line comment is turned
+-- into several lines for subsequent outputting with correct indentation for
+-- each line.
+mkComment :: RealLocated String -> RealLocated Comment
+mkComment (L l s) =
+  L l . Comment . fmap dropTrailing $
+    if "{-" `isPrefixOf` s
+      then case NE.nonEmpty (lines s) of
+        Nothing -> s :| []
+        Just (x :| xs) ->
+          let getIndent y =
+                if all isSpace y
+                  then startIndent
+                  else length (takeWhile isSpace y)
+              n = minimum (startIndent : fmap getIndent xs)
+           in x :| (drop n <$> xs)
+      else s :| []
+  where
+    dropTrailing = dropWhileEnd isSpace
+    startIndent = srcSpanStartCol l - 1
+
+-- | Get a 'String' from 'GHC.AnnotationComment'.
+unAnnotationComment :: GHC.AnnotationComment -> Maybe String
+unAnnotationComment = \case
+  GHC.AnnDocCommentNext _ -> Nothing -- @-- |@
+  GHC.AnnDocCommentPrev _ -> Nothing -- @-- ^@
+  GHC.AnnDocCommentNamed _ -> Nothing -- @-- $@
+  GHC.AnnDocSection _ _ -> Nothing -- @-- *@
+  GHC.AnnDocOptions s -> Just s
+  GHC.AnnLineComment s -> Just s
+  GHC.AnnBlockComment s -> Just s
+
+liftMaybe :: Located (Maybe a) -> Maybe (Located a)
+liftMaybe = \case
+  L _ Nothing -> Nothing
+  L l (Just a) -> Just (L l a)
+
+toRealSpan :: Located a -> Maybe (RealLocated a)
+toRealSpan (L (RealSrcSpan l) a) = Just (L l a)
+toRealSpan _ = Nothing
+
+-- | If a given comment is a pragma, return it in parsed form in 'Right'.
+-- Otherwise return the original comment unchanged.
+partitionComments ::
+  RealLocated String ->
+  Either (RealLocated String) Pragma
+partitionComments input =
+  case parsePragma (unLoc input) of
+    Nothing -> Left input
+    Just pragma -> Right pragma
diff --git a/src/Ormolu/Parser/Pragma.hs b/src/Ormolu/Parser/Pragma.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Parser/Pragma.hs
@@ -0,0 +1,86 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+-- | A module for parsing of pragmas from comments.
+module Ormolu.Parser.Pragma
+  ( Pragma (..),
+    parsePragma,
+  )
+where
+
+import Control.Monad
+import Data.Char (isSpace, toLower)
+import Data.List
+import qualified EnumSet as ES
+import FastString (mkFastString, unpackFS)
+import qualified Lexer as L
+import Module (ComponentId (..), newSimpleUnitId)
+import SrcLoc
+import StringBuffer
+
+-- | Ormolu's representation of pragmas.
+data Pragma
+  = -- | Language pragma
+    PragmaLanguage [String]
+  | -- | GHC options pragma
+    PragmaOptionsGHC String
+  | -- | Haddock options pragma
+    PragmaOptionsHaddock String
+  deriving (Show, Eq)
+
+-- | Extract a pragma from a comment if possible, or return 'Nothing'
+-- otherwise.
+parsePragma ::
+  -- | Comment to try to parse
+  String ->
+  Maybe Pragma
+parsePragma input = do
+  inputNoPrefix <- stripPrefix "{-#" input
+  guard ("#-}" `isSuffixOf` input)
+  let contents = take (length inputNoPrefix - 3) inputNoPrefix
+      (pragmaName, cs) = (break isSpace . dropWhile isSpace) contents
+  case toLower <$> pragmaName of
+    "language" -> PragmaLanguage <$> parseExtensions cs
+    "options_ghc" -> Just $ PragmaOptionsGHC (trimSpaces cs)
+    "options_haddock" -> Just $ PragmaOptionsHaddock (trimSpaces cs)
+    _ -> Nothing
+  where
+    trimSpaces :: String -> String
+    trimSpaces = dropWhileEnd isSpace . dropWhile isSpace
+
+-- | Assuming the input consists of a series of tokens from a language
+-- pragma, return the set of enabled extensions.
+parseExtensions :: String -> Maybe [String]
+parseExtensions str = tokenize str >>= go
+  where
+    go = \case
+      (L.ITconid ext : []) -> return [unpackFS ext]
+      (L.ITconid ext : L.ITcomma : xs) -> (unpackFS ext :) <$> go xs
+      _ -> Nothing
+
+-- | Tokenize a given input using GHC's lexer.
+tokenize :: String -> Maybe [L.Token]
+tokenize input =
+  case L.unP pLexer parseState of
+    L.PFailed {} -> Nothing
+    L.POk _ x -> Just x
+  where
+    location = mkRealSrcLoc (mkFastString "") 1 1
+    buffer = stringToStringBuffer input
+    parseState = L.mkPStatePure parserFlags buffer location
+    parserFlags = L.ParserFlags
+      { L.pWarningFlags = ES.empty,
+        L.pExtensionFlags = ES.empty,
+        L.pThisPackage = newSimpleUnitId (ComponentId (mkFastString "")),
+        L.pExtsBitmap = 0xffffffffffffffff
+      }
+
+-- | Haskell lexer.
+pLexer :: L.P [L.Token]
+pLexer = go
+  where
+    go = do
+      r <- L.lexer False return
+      case unLoc r of
+        L.ITeof -> return []
+        x -> (x :) <$> go
diff --git a/src/Ormolu/Parser/Result.hs b/src/Ormolu/Parser/Result.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Parser/Result.hs
@@ -0,0 +1,36 @@
+{-# LANGUAGE RecordWildCards #-}
+
+-- | A type for result of parsing.
+module Ormolu.Parser.Result
+  ( ParseResult (..),
+    prettyPrintParseResult,
+  )
+where
+
+import GHC
+import Ormolu.Parser.Anns
+import Ormolu.Parser.CommentStream
+import Ormolu.Parser.Pragma (Pragma)
+
+-- | A collection of data that represents a parsed module in Ormolu.
+data ParseResult
+  = ParseResult
+      { -- | 'ParsedSource' from GHC
+        prParsedSource :: ParsedSource,
+        -- | Ormolu-specfic representation of annotations
+        prAnns :: Anns,
+        -- | Comment stream
+        prCommentStream :: CommentStream,
+        -- | Extensions enabled in that module
+        prExtensions :: [Pragma]
+      }
+
+-- | Pretty-print a 'ParseResult'.
+prettyPrintParseResult :: ParseResult -> String
+prettyPrintParseResult ParseResult {..} =
+  unlines
+    [ "parse result:",
+      "  comment stream:",
+      showCommentStream prCommentStream
+      -- XXX extend as needed
+    ]
diff --git a/src/Ormolu/Printer.hs b/src/Ormolu/Printer.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer.hs
@@ -0,0 +1,28 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Pretty-printer for Haskell AST.
+module Ormolu.Printer
+  ( printModule,
+  )
+where
+
+import Data.Text (Text)
+import Ormolu.Parser.Result
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Module
+import Ormolu.Printer.SpanStream
+
+-- | Render a module.
+printModule ::
+  -- | Result of parsing
+  ParseResult ->
+  -- | Resulting rendition
+  Text
+printModule ParseResult {..} =
+  runR
+    (p_hsModule prExtensions prParsedSource)
+    (mkSpanStream prParsedSource)
+    prCommentStream
+    prAnns
diff --git a/src/Ormolu/Printer/Combinators.hs b/src/Ormolu/Printer/Combinators.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Combinators.hs
@@ -0,0 +1,287 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Printing combinators. The definitions here are presented in such an
+-- order so you can just go through the Haddocks and by the end of the file
+-- you should have a pretty good idea how to program rendering logic.
+module Ormolu.Printer.Combinators
+  ( -- * The 'R' monad
+    R,
+    runR,
+    getAnns,
+    getEnclosingSpan,
+
+    -- * Combinators
+
+    -- ** Basic
+    txt,
+    atom,
+    space,
+    newline,
+    inci,
+    located,
+    located',
+    switchLayout,
+    Layout (..),
+    vlayout,
+    getLayout,
+    breakpoint,
+    breakpoint',
+
+    -- ** Formatting lists
+    sep,
+    sepSemi,
+    canUseBraces,
+    useBraces,
+    dontUseBraces,
+
+    -- ** Wrapping
+    BracketStyle (..),
+    sitcc,
+    backticks,
+    banana,
+    braces,
+    brackets,
+    parens,
+    parensHash,
+    pragmaBraces,
+    pragma,
+
+    -- ** Literals
+    comma,
+
+    -- ** Comments
+    HaddockStyle (..),
+    setLastCommentSpan,
+    getLastCommentSpan,
+  )
+where
+
+import Control.Monad
+import Data.Data (Data)
+import Data.List (intersperse)
+import Data.Text (Text)
+import Ormolu.Printer.Comments
+import Ormolu.Printer.Internal
+import Ormolu.Utils (isModule)
+import SrcLoc
+
+----------------------------------------------------------------------------
+-- Basic
+
+-- | Enter a 'Located' entity. This combinator handles outputting comments
+-- and sets layout (single-line vs multi-line) for the inner computation.
+-- Roughly, the rule for using 'located' is that every time there is a
+-- 'Located' wrapper, it should be “discharged” with a corresponding
+-- 'located' invocation.
+located ::
+  Data a =>
+  -- | Thing to enter
+  Located a ->
+  -- | How to render inner value
+  (a -> R ()) ->
+  R ()
+located loc f = do
+  let withRealLocated (L l a) g =
+        case l of
+          UnhelpfulSpan _ -> return ()
+          RealSrcSpan l' -> g (L l' a)
+  withRealLocated loc spitPrecedingComments
+  let setEnclosingSpan =
+        case getLoc loc of
+          UnhelpfulSpan _ -> id
+          RealSrcSpan orf ->
+            if isModule (unLoc loc)
+              then id
+              else withEnclosingSpan orf
+  setEnclosingSpan $ switchLayout [getLoc loc] (f (unLoc loc))
+  withRealLocated loc spitFollowingComments
+
+-- | A version of 'located' with arguments flipped.
+located' ::
+  Data a =>
+  -- | How to render inner value
+  (a -> R ()) ->
+  -- | Thing to enter
+  Located a ->
+  R ()
+located' = flip located
+
+-- | Set layout according to combination of given 'SrcSpan's for a given.
+-- Use this only when you need to set layout based on e.g. combined span of
+-- several elements when there is no corresponding 'Located' wrapper
+-- provided by GHC AST. It is relatively rare that this one is needed.
+--
+-- Given empty list this function will set layout to single line.
+switchLayout ::
+  -- | Span that controls layout
+  [SrcSpan] ->
+  -- | Computation to run with changed layout
+  R () ->
+  R ()
+switchLayout spans' = enterLayout (spansLayout spans')
+
+-- | Which layout combined spans result in?
+spansLayout :: [SrcSpan] -> Layout
+spansLayout = \case
+  [] -> SingleLine
+  (x : xs) ->
+    if isOneLineSpan (foldr combineSrcSpans x xs)
+      then SingleLine
+      else MultiLine
+
+-- | Insert a space if enclosing layout is single-line, or newline if it's
+-- multiline.
+--
+-- > breakpoint = vlayout space newline
+breakpoint :: R ()
+breakpoint = vlayout space newline
+
+-- | Similar to 'breakpoint' but outputs nothing in case of single-line
+-- layout.
+--
+-- > breakpoint' = vlayout (return ()) newline
+breakpoint' :: R ()
+breakpoint' = vlayout (return ()) newline
+
+----------------------------------------------------------------------------
+-- Formatting lists
+
+-- | Render a collection of elements inserting a separator between them.
+sep ::
+  -- | Separator
+  R () ->
+  -- | How to render an element
+  (a -> R ()) ->
+  -- | Elements to render
+  [a] ->
+  R ()
+sep s f xs = sequence_ (intersperse s (f <$> xs))
+
+-- | Render a collection of elements layout-sensitively using given printer,
+-- inserting semicolons if necessary and respecting 'useBraces' and
+-- 'dontUseBraces' combinators.
+--
+-- > useBraces $ sepSemi txt ["foo", "bar"]
+-- >   == vlayout (txt "{ foo; bar }") (txt "foo\nbar")
+--
+-- > dontUseBraces $ sepSemi txt ["foo", "bar"]
+-- >   == vlayout (txt "foo; bar") (txt "foo\nbar")
+sepSemi ::
+  -- | How to render an element
+  (a -> R ()) ->
+  -- | Elements to render
+  [a] ->
+  R ()
+sepSemi f xs = vlayout singleLine multiLine
+  where
+    singleLine = do
+      ub <- canUseBraces
+      case xs of
+        [] -> when ub $ txt "{}"
+        xs' ->
+          if ub
+            then do
+              txt "{ "
+              sep (txt "; ") (dontUseBraces . f) xs'
+              txt " }"
+            else sep (txt "; ") f xs'
+    multiLine =
+      sep newline (dontUseBraces . f) xs
+
+----------------------------------------------------------------------------
+-- Wrapping
+
+-- | 'BracketStyle' controlling how closing bracket is rendered.
+data BracketStyle
+  = -- | Normal
+    N
+  | -- | Shifted one level
+    S
+
+-- | Surround given entity by backticks.
+backticks :: R () -> R ()
+backticks m = do
+  txt "`"
+  m
+  txt "`"
+
+-- | Surround given entity by banana brackets (i.e., from arrow notation.)
+banana :: R () -> R ()
+banana = brackets_ True "(|" "|)" N
+
+-- | Surround given entity by curly braces @{@ and  @}@.
+braces :: BracketStyle -> R () -> R ()
+braces = brackets_ False "{" "}"
+
+-- | Surround given entity by square brackets @[@ and @]@.
+brackets :: BracketStyle -> R () -> R ()
+brackets = brackets_ False "[" "]"
+
+-- | Surround given entity by parentheses @(@ and @)@.
+parens :: BracketStyle -> R () -> R ()
+parens = brackets_ False "(" ")"
+
+-- | Surround given entity by @(# @ and @ #)@.
+parensHash :: BracketStyle -> R () -> R ()
+parensHash = brackets_ True "(#" "#)"
+
+-- | Braces as used for pragmas: @{-#@ and @#-}@.
+pragmaBraces :: R () -> R ()
+pragmaBraces m = sitcc $ do
+  txt "{-#"
+  space
+  m
+  breakpoint
+  inci (txt "#-}")
+
+-- | Surround the body with a pragma name and 'pragmaBraces'.
+pragma ::
+  -- | Pragma text
+  Text ->
+  -- | Pragma body
+  R () ->
+  R ()
+pragma pragmaText body = pragmaBraces $ do
+  txt pragmaText
+  breakpoint
+  body
+
+-- | A helper for defining wrappers like 'parens' and 'braces'.
+brackets_ ::
+  -- | Insert breakpoints around brackets
+  Bool ->
+  -- | Opening bracket
+  Text ->
+  -- | Closing bracket
+  Text ->
+  -- | Bracket style
+  BracketStyle ->
+  -- | Inner expression
+  R () ->
+  R ()
+brackets_ needBreaks open close style m = sitcc (vlayout singleLine multiLine)
+  where
+    singleLine = do
+      txt open
+      when needBreaks space
+      m
+      when needBreaks space
+      txt close
+    multiLine = do
+      txt open
+      if needBreaks
+        then newline >> inci m
+        else space >> sitcc m
+      newline
+      case style of
+        N -> txt close
+        S -> inci (txt close)
+
+----------------------------------------------------------------------------
+-- Literals
+
+-- | Print @,@.
+comma :: R ()
+comma = txt ","
diff --git a/src/Ormolu/Printer/Comments.hs b/src/Ormolu/Printer/Comments.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Comments.hs
@@ -0,0 +1,295 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+-- | Helpers for formatting of comments. This is low-level code, use
+-- "Ormolu.Printer.Combinators" unless you know what you are doing.
+module Ormolu.Printer.Comments
+  ( spitPrecedingComments,
+    spitFollowingComments,
+    spitRemainingComments,
+  )
+where
+
+import Control.Monad
+import Data.Coerce (coerce)
+import Data.Data (Data)
+import qualified Data.List.NonEmpty as NE
+import qualified Data.Text as T
+import Ormolu.Parser.CommentStream
+import Ormolu.Printer.Internal
+import Ormolu.Utils (isModule)
+import SrcLoc
+
+----------------------------------------------------------------------------
+-- Top-level
+
+-- | Output all preceding comments for an element at given location.
+spitPrecedingComments ::
+  Data a =>
+  -- | AST element to attach comments to
+  RealLocated a ->
+  R ()
+spitPrecedingComments ref = do
+  r <- getLastCommentSpan
+  case r of
+    Just (Just Pipe, _) ->
+      -- We should not insert comments between pipe Haddock and the thing
+      -- it's attached to.
+      return ()
+    _ -> do
+      gotSome <- handleCommentSeries (spitPrecedingComment ref)
+      when gotSome $ do
+        -- Insert a blank line between the preceding comments and the thing
+        -- after them if there was a blank line in the input.
+        lastSpn <- fmap snd <$> getLastCommentSpan
+        when (needsNewlineBefore (getLoc ref) lastSpn) newline
+
+-- | Output all comments following an element at given location.
+spitFollowingComments ::
+  Data a =>
+  -- | AST element of attach comments to
+  RealLocated a ->
+  R ()
+spitFollowingComments ref = do
+  trimSpanStream (getLoc ref)
+  void $ handleCommentSeries (spitFollowingComment ref)
+
+-- | Output all remaining comments in the comment stream.
+spitRemainingComments :: R ()
+spitRemainingComments = void $ handleCommentSeries spitRemainingComment
+
+----------------------------------------------------------------------------
+-- Single-comment functions
+
+-- | Output a single preceding comment for an element at given location.
+spitPrecedingComment ::
+  Data a =>
+  -- | AST element to attach comments to
+  RealLocated a ->
+  -- | Location of last comment in the series
+  Maybe RealSrcSpan ->
+  -- | Are we done?
+  R Bool
+spitPrecedingComment (L ref a) mlastSpn = do
+  let p (L l _) = realSrcSpanEnd l <= realSrcSpanStart ref
+  withPoppedComment p $ \l comment -> do
+    dirtyLine <-
+      case mlastSpn of
+        -- NOTE When the current line is dirty it means that something that
+        -- can have comments attached to it is already on the line. To avoid
+        -- problems with idempotence we cannot output the first comment
+        -- immediately because it'll be attached to the previous element (on
+        -- the same line) on the next run, so we play safe here and output
+        -- an extra 'newline' in this case.
+        Nothing -> isLineDirty -- only for very first preceding comment
+        Just _ -> return False
+    when (dirtyLine || needsNewlineBefore l mlastSpn) newline
+    spitCommentNow l comment
+    if theSameLinePre l ref && not (isModule a)
+      then space
+      else newline
+
+-- | Output a comment that follows element at given location immediately on
+-- the same line, if there is any.
+spitFollowingComment ::
+  Data a =>
+  -- | AST element to attach comments to
+  RealLocated a ->
+  -- | Location of last comment in the series
+  Maybe RealSrcSpan ->
+  -- | Are we done?
+  R Bool
+spitFollowingComment (L ref a) mlastSpn = do
+  mnSpn <- nextEltSpan
+  -- Get first enclosing span that is not equal to reference span, i.e. it's
+  -- truly something enclosing the AST element.
+  meSpn <- getEnclosingSpan (/= ref)
+  withPoppedComment (commentFollowsElt ref mnSpn meSpn mlastSpn) $ \l comment ->
+    if theSameLinePost l ref && not (isModule a)
+      then
+        if isMultilineComment comment
+          then space >> spitCommentNow l comment
+          else spitCommentPending OnTheSameLine l comment
+      else do
+        when (needsNewlineBefore l mlastSpn) $
+          registerPendingCommentLine OnNextLine ""
+        spitCommentPending OnNextLine l comment
+
+-- | Output a single remaining comment from the comment stream.
+spitRemainingComment ::
+  -- | Location of last comment in the series
+  Maybe RealSrcSpan ->
+  -- | Are we done?
+  R Bool
+spitRemainingComment mlastSpn =
+  withPoppedComment (const True) $ \l comment -> do
+    when (needsNewlineBefore l mlastSpn) newline
+    spitCommentNow l comment
+    newline
+
+----------------------------------------------------------------------------
+-- Helpers
+
+-- | Output series of comments.
+handleCommentSeries ::
+  -- | Given location of previous comment, output the next comment
+  -- returning 'True' if we're done
+  (Maybe RealSrcSpan -> R Bool) ->
+  -- | Whether we printed any comments
+  R Bool
+handleCommentSeries f = go False
+  where
+    go gotSome = do
+      done <- getLastCommentSpan >>= f . fmap snd
+      if done
+        then return gotSome
+        else go True
+
+-- | Try to pop a comment using given predicate and if there is a comment
+-- matching the predicate, print it out.
+withPoppedComment ::
+  -- | Comment predicate
+  (RealLocated Comment -> Bool) ->
+  -- | Printing function
+  (RealSrcSpan -> Comment -> R ()) ->
+  -- | Are we done?
+  R Bool
+withPoppedComment p f = do
+  r <- popComment p
+  case r of
+    Nothing -> return True
+    Just (L l comment) -> False <$ f l comment
+
+-- | Determine if we need to insert a newline between current comment and
+-- last printed comment.
+needsNewlineBefore ::
+  -- | Current comment span
+  RealSrcSpan ->
+  -- | Last printed comment span
+  Maybe RealSrcSpan ->
+  Bool
+needsNewlineBefore l mlastSpn =
+  case mlastSpn of
+    Nothing -> False
+    Just lastSpn ->
+      srcSpanStartLine l > srcSpanEndLine lastSpn + 1
+
+-- | Is the preceding comment and AST element are on the same line?
+theSameLinePre ::
+  -- | Current comment span
+  RealSrcSpan ->
+  -- | AST element location
+  RealSrcSpan ->
+  Bool
+theSameLinePre l ref =
+  srcSpanEndLine l == srcSpanStartLine ref
+
+-- | Is the following comment and AST element are on the same line?
+theSameLinePost ::
+  -- | Current comment span
+  RealSrcSpan ->
+  -- | AST element location
+  RealSrcSpan ->
+  Bool
+theSameLinePost l ref =
+  srcSpanStartLine l == srcSpanEndLine ref
+
+-- | Determine if given comment follows AST element.
+commentFollowsElt ::
+  -- | Location of AST element
+  RealSrcSpan ->
+  -- | Location of next AST element
+  Maybe RealSrcSpan ->
+  -- | Location of enclosing AST element
+  Maybe RealSrcSpan ->
+  -- | Location of last comment in the series
+  Maybe RealSrcSpan ->
+  -- | Comment to test
+  RealLocated Comment ->
+  Bool
+commentFollowsElt ref mnSpn meSpn mlastSpn (L l comment) =
+  -- A comment follows a AST element if all 4 conditions are satisfied:
+  goesAfter
+    && logicallyFollows
+    && noEltBetween
+    && (continuation || lastInEnclosing || supersedesParentElt)
+  where
+    -- 1) The comment starts after end of the AST element:
+    goesAfter =
+      realSrcSpanStart l >= realSrcSpanEnd ref
+    -- 2) The comment logically belongs to the element, four cases:
+    logicallyFollows =
+      theSameLinePost l ref -- a) it's on the same line
+        || isPrevHaddock comment -- b) it's a Haddock string starting with -- ^
+        || continuation -- c) it's a continuation of a comment block
+        || lastInEnclosing -- d) it's the last element in the enclosing construct
+
+    -- 3) There is no other AST element between this element and the comment:
+    noEltBetween =
+      case mnSpn of
+        Nothing -> True
+        Just nspn ->
+          realSrcSpanStart nspn >= realSrcSpanEnd l
+    -- 4) Less obvious: if column of comment is closer to the start of
+    -- enclosing element, it probably related to that parent element, not to
+    -- the current child element. This rule is important because otherwise
+    -- all comments would end up assigned to closest inner elements, and
+    -- parent elements won't have a chance to get any comments assigned to
+    -- them. This is not OK because comments will get indented according to
+    -- the AST elements they are attached to.
+    --
+    -- Skip this rule if the comment is a continuation of a comment block.
+    supersedesParentElt =
+      case meSpn of
+        Nothing -> True
+        Just espn ->
+          let startColumn = srcLocCol . realSrcSpanStart
+           in if startColumn espn > startColumn ref
+                then True
+                else
+                  abs (startColumn espn - startColumn l)
+                    >= abs (startColumn ref - startColumn l)
+    continuation =
+      case mlastSpn of
+        Nothing -> False
+        Just spn -> srcSpanEndLine spn + 1 == srcSpanStartLine l
+    lastInEnclosing =
+      case meSpn of
+        -- When there is no enclosing element, return false
+        Nothing -> False
+        -- When there is an enclosing element,
+        Just espn ->
+          let -- Make sure that the comment is inside the enclosing element
+              insideParent = realSrcSpanEnd l <= realSrcSpanEnd espn
+              -- And check if the next element is outside of the parent
+              nextOutsideParent = case mnSpn of
+                Nothing -> True
+                Just nspn -> realSrcSpanEnd espn < realSrcSpanStart nspn
+           in insideParent && nextOutsideParent
+
+-- | Output a 'Comment' immediately. This is a low-level printing function.
+spitCommentNow :: RealSrcSpan -> Comment -> R ()
+spitCommentNow spn comment = do
+  sitcc
+    . sequence_
+    . NE.intersperse newline
+    . fmap (txt . T.pack)
+    . coerce
+    $ comment
+  setLastCommentSpan Nothing spn
+
+-- | Output a 'Comment' at the end of correct line or after it depending on
+-- 'CommentPosition'. Used for comments that may potentially follow on the
+-- same line as something we just rendered, but not immediately after it.
+spitCommentPending :: CommentPosition -> RealSrcSpan -> Comment -> R ()
+spitCommentPending position spn comment = do
+  let wrapper = case position of
+        OnTheSameLine -> sitcc
+        OnNextLine -> id
+  wrapper
+    . sequence_
+    . NE.toList
+    . fmap (registerPendingCommentLine position . T.pack)
+    . coerce
+    $ comment
+  setLastCommentSpan Nothing spn
diff --git a/src/Ormolu/Printer/Internal.hs b/src/Ormolu/Printer/Internal.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Internal.hs
@@ -0,0 +1,514 @@
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RankNTypes #-}
+
+-- | In most cases import "Ormolu.Printer.Combinators" instead, these
+-- functions are the low-level building blocks and should not be used on
+-- their own. The 'R' monad is re-exported from "Ormolu.Printer.Combinators"
+-- as well.
+module Ormolu.Printer.Internal
+  ( -- * The 'R' monad
+    R,
+    runR,
+
+    -- * Internal functions
+    txt,
+    atom,
+    space,
+    newline,
+    isLineDirty,
+    inci,
+    sitcc,
+    Layout (..),
+    enterLayout,
+    vlayout,
+    getLayout,
+
+    -- * Helpers for braces
+    useBraces,
+    dontUseBraces,
+    canUseBraces,
+
+    -- * Special helpers for comment placement
+    CommentPosition (..),
+    registerPendingCommentLine,
+    trimSpanStream,
+    nextEltSpan,
+    popComment,
+    getEnclosingSpan,
+    withEnclosingSpan,
+    HaddockStyle (..),
+    setLastCommentSpan,
+    getLastCommentSpan,
+
+    -- * Annotations
+    getAnns,
+  )
+where
+
+import Control.Monad.Reader
+import Control.Monad.State.Strict
+import Data.Bool (bool)
+import Data.Coerce
+import Data.Maybe (listToMaybe)
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified Data.Text.Lazy as TL
+import Data.Text.Lazy.Builder
+import GHC
+import Ormolu.Parser.Anns
+import Ormolu.Parser.CommentStream
+import Ormolu.Printer.SpanStream
+import Ormolu.Utils (showOutputable)
+import Outputable (Outputable)
+import SrcLoc
+
+----------------------------------------------------------------------------
+-- The 'R' monad
+
+-- | The 'R' monad hosts combinators that allow us to describe how to render
+-- AST.
+newtype R a = R (ReaderT RC (State SC) a)
+  deriving (Functor, Applicative, Monad)
+
+-- | Reader context of 'R'. This should be used when we control rendering by
+-- enclosing certain expressions with wrappers.
+data RC
+  = RC
+      { -- | Indentation level, as the column index we need to start from after
+        -- a newline if we break lines
+        rcIndent :: !Int,
+        -- | Current layout
+        rcLayout :: Layout,
+        -- | Spans of enclosing elements of AST
+        rcEnclosingSpans :: [RealSrcSpan],
+        -- | Collection of annotations
+        rcAnns :: Anns,
+        -- | If the last expression in the layout can use braces
+        rcCanUseBraces :: Bool
+      }
+
+-- | State context of 'R'.
+data SC
+  = SC
+      { -- | Index of the next column to render
+        scColumn :: !Int,
+        -- | Rendered source code so far
+        scBuilder :: Builder,
+        -- | Span stream
+        scSpanStream :: SpanStream,
+        -- | Comment stream
+        scCommentStream :: CommentStream,
+        -- | Pending comment lines (in reverse order) to be inserted before next
+        -- newline, 'Int' is the indentation level
+        scPendingComments :: ![(CommentPosition, Int, Text)],
+        -- | Whether the current line is “dirty”, that is, already contains
+        -- atoms that can have comments attached to them
+        scDirtyLine :: !Bool,
+        -- | Whether to output a space before the next output
+        scRequestedDelimiter :: !RequestedDelimiter,
+        -- | Span of last output comment
+        scLastCommentSpan :: !(Maybe (Maybe HaddockStyle, RealSrcSpan))
+      }
+
+-- | Make sure next output is delimited by one of the following.
+data RequestedDelimiter
+  = -- | A space
+    RequestedSpace
+  | -- | A newline
+    RequestedNewline
+  | -- | Nothing
+    RequestedNothing
+  | -- | We just output a newline
+    AfterNewline
+  | -- | We haven't printed anything yet
+    VeryBeginning
+  deriving (Eq, Show)
+
+-- | 'Layout' options.
+data Layout
+  = -- | Put everything on single line
+    SingleLine
+  | -- | Use multiple lines
+    MultiLine
+  deriving (Eq, Show)
+
+-- | Modes for rendering of pending comments.
+data CommentPosition
+  = -- | Put the comment on the same line
+    OnTheSameLine
+  | -- | Put the comment on next line
+    OnNextLine
+  deriving (Eq, Show)
+
+-- | Run an 'R' monad.
+runR ::
+  -- | Monad to run
+  R () ->
+  -- | Span stream
+  SpanStream ->
+  -- | Comment stream
+  CommentStream ->
+  -- | Annotations
+  Anns ->
+  -- | Resulting rendition
+  Text
+runR (R m) sstream cstream anns =
+  TL.toStrict . toLazyText . scBuilder $ execState (runReaderT m rc) sc
+  where
+    rc = RC
+      { rcIndent = 0,
+        rcLayout = MultiLine,
+        rcEnclosingSpans = [],
+        rcAnns = anns,
+        rcCanUseBraces = False
+      }
+    sc = SC
+      { scColumn = 0,
+        scBuilder = mempty,
+        scSpanStream = sstream,
+        scCommentStream = cstream,
+        scPendingComments = [],
+        scDirtyLine = False,
+        scRequestedDelimiter = VeryBeginning,
+        scLastCommentSpan = Nothing
+      }
+
+----------------------------------------------------------------------------
+-- Internal functions
+
+-- | Output a fixed 'Text' fragment. The argument may not contain any line
+-- breaks. 'txt' is used to output all sorts of “fixed” bits of syntax like
+-- keywords and pipes @|@ in functional dependencies.
+--
+-- To separate various bits of syntax with white space use 'space' instead
+-- of @'txt' " "@. To output 'Outputable' Haskell entities like numbers use
+-- 'atom'.
+txt ::
+  -- | 'Text' to output
+  Text ->
+  R ()
+txt = spit False False
+
+-- | Output 'Outputable' fragment of AST. This can be used to output numeric
+-- literals and similar. Everything that doesn't have inner structure but
+-- does have an 'Outputable' instance.
+atom ::
+  Outputable a =>
+  a ->
+  R ()
+atom = spit True False . T.pack . showOutputable
+
+-- | Low-level non-public helper to define 'txt' and 'atom'.
+spit ::
+  -- | Should we mark the line as dirty?
+  Bool ->
+  -- | Used during outputting of pending comments?
+  Bool ->
+  -- | 'Text' to output
+  Text ->
+  R ()
+spit dirty printingComments txt' = do
+  requestedDel <- R (gets scRequestedDelimiter)
+  case requestedDel of
+    RequestedNewline -> do
+      R . modify $ \sc ->
+        sc
+          { scRequestedDelimiter = RequestedNothing
+          }
+      if printingComments
+        then newlineRaw
+        else newline
+    _ -> return ()
+  R $ do
+    i <- asks rcIndent
+    c <- gets scColumn
+    let spaces =
+          if c < i
+            then T.replicate (i - c) " "
+            else bool mempty " " (requestedDel == RequestedSpace)
+        indentedTxt = spaces <> txt'
+    modify $ \sc ->
+      sc
+        { scBuilder = scBuilder sc <> fromText indentedTxt,
+          scColumn = scColumn sc + T.length indentedTxt,
+          scDirtyLine = scDirtyLine sc || dirty,
+          scRequestedDelimiter = RequestedNothing,
+          scLastCommentSpan =
+            -- NOTE If there are pending comments, do not reset last comment
+            -- location.
+            if printingComments || (not . null . scPendingComments) sc
+              then scLastCommentSpan sc
+              else Nothing
+        }
+
+-- | This primitive /does not/ necessarily output a space. It just ensures
+-- that the next thing that will be printed on the same line will be
+-- separated by a single space from the previous output. Using this
+-- combinator twice results in at most one space.
+--
+-- In practice this design prevents trailing white space and makes it hard
+-- to output more than one delimiting space in a row, which is what we
+-- usually want.
+space :: R ()
+space = R . modify $ \sc ->
+  sc
+    { scRequestedDelimiter = case scRequestedDelimiter sc of
+        RequestedNothing -> RequestedSpace
+        other -> other
+    }
+
+-- | Output a newline. First time 'newline' is used after some non-'newline'
+-- output it gets inserted immediately. Second use of 'newline' does not
+-- output anything but makes sure that the next non-white space output will
+-- be prefixed by a newline. Using 'newline' more than twice in a row has no
+-- effect. Also, using 'newline' at the very beginning has no effect, this
+-- is to avoid leading whitespace.
+--
+-- Similarly to 'space', this design prevents trailing newlines and makes it
+-- hard to output more than one blank newline in a row.
+newline :: R ()
+newline = do
+  cs <- reverse <$> R (gets scPendingComments)
+  case cs of
+    [] -> newlineRaw
+    ((position, _, _) : _) -> do
+      case position of
+        OnTheSameLine -> space
+        OnNextLine -> newlineRaw
+      R . forM_ cs $ \(_, indent, txt') ->
+        let modRC rc =
+              rc
+                { rcIndent = indent
+                }
+            R m = do
+              unless (T.null txt') $
+                spit False True txt'
+              newlineRaw
+         in local modRC m
+      R . modify $ \sc ->
+        sc
+          { scPendingComments = []
+          }
+
+-- | Low-level newline primitive. This one always just inserts a newline, no
+-- hooks can be attached.
+newlineRaw :: R ()
+newlineRaw = R . modify $ \sc ->
+  let requestedDel = scRequestedDelimiter sc
+      builderSoFar = scBuilder sc
+   in sc
+        { scBuilder = case requestedDel of
+            AfterNewline -> builderSoFar
+            RequestedNewline -> builderSoFar
+            VeryBeginning -> builderSoFar
+            _ -> builderSoFar <> "\n",
+          scColumn = 0,
+          scDirtyLine = False,
+          scRequestedDelimiter = case scRequestedDelimiter sc of
+            AfterNewline -> RequestedNewline
+            RequestedNewline -> RequestedNewline
+            VeryBeginning -> VeryBeginning
+            _ -> AfterNewline
+        }
+
+-- | Check if the current line is “dirty”, that is, there is something on it
+-- that can have comments attached to it.
+isLineDirty :: R Bool
+isLineDirty = R (gets scDirtyLine)
+
+-- | Increase indentation level by one indentation step for the inner
+-- computation. 'inci' should be used when a part of code must be more
+-- indented relative to the parts outside of 'inci' in order for the output
+-- to be valid Haskell. When layout is single-line there is no obvious
+-- effect, but with multi-line layout correct indentation levels matter.
+inci :: R () -> R ()
+inci (R m) = R (local modRC m)
+  where
+    modRC rc =
+      rc
+        { rcIndent = rcIndent rc + indentStep
+        }
+
+-- | Set indentation level for the inner computation equal to current
+-- column. This makes sure that the entire inner block is uniformly
+-- \"shifted\" to the right. Only works (and makes sense) when enclosing
+-- layout is multi-line.
+sitcc :: R () -> R ()
+sitcc (R m) = do
+  requestedDel <- R (gets scRequestedDelimiter)
+  i <- R (asks rcIndent)
+  c <- R (gets scColumn)
+  let modRC rc =
+        rc
+          { rcIndent = max i c + bool 0 1 (requestedDel == RequestedSpace)
+          }
+  vlayout (R m) . R $ do
+    modify $ \sc ->
+      sc
+        { scRequestedDelimiter = case requestedDel of
+            RequestedSpace -> RequestedNothing
+            other -> other
+        }
+    local modRC m
+
+-- | Set 'Layout' for internal computation.
+enterLayout :: Layout -> R () -> R ()
+enterLayout l (R m) = R (local modRC m)
+  where
+    modRC rc =
+      rc
+        { rcLayout = l
+        }
+
+-- | Do one or another thing depending on current 'Layout'.
+vlayout ::
+  -- | Single line
+  R a ->
+  -- | Multi line
+  R a ->
+  R a
+vlayout sline mline = do
+  l <- getLayout
+  case l of
+    SingleLine -> sline
+    MultiLine -> mline
+
+-- | Get current 'Layout'.
+getLayout :: R Layout
+getLayout = R (asks rcLayout)
+
+----------------------------------------------------------------------------
+-- Special helpers for comment placement
+
+-- | Register a comment line for outputting. It will be inserted right
+-- before next newline. When the comment goes after something else on the
+-- same line, a space will be inserted between preceding text and the
+-- comment when necessary.
+registerPendingCommentLine ::
+  -- | Comment position
+  CommentPosition ->
+  -- | 'Text' to output
+  Text ->
+  R ()
+registerPendingCommentLine position txt' = R $ do
+  i <- asks rcIndent
+  modify $ \sc ->
+    sc
+      { scPendingComments = (position, i, txt') : scPendingComments sc
+      }
+
+-- | Drop elements that begin before or at the same place as given
+-- 'SrcSpan'.
+trimSpanStream ::
+  -- | Reference span
+  RealSrcSpan ->
+  R ()
+trimSpanStream ref = do
+  let leRef :: RealSrcSpan -> Bool
+      leRef x = realSrcSpanStart x <= realSrcSpanStart ref
+  R . modify $ \sc ->
+    sc
+      { scSpanStream = coerce (dropWhile leRef) (scSpanStream sc)
+      }
+
+-- | Get location of next element in AST.
+nextEltSpan :: R (Maybe RealSrcSpan)
+nextEltSpan = listToMaybe . coerce <$> R (gets scSpanStream)
+
+-- | Pop a 'Comment' from the 'CommentStream' if given predicate is
+-- satisfied and there are comments in the stream.
+popComment ::
+  (RealLocated Comment -> Bool) ->
+  R (Maybe (RealLocated Comment))
+popComment f = R $ do
+  CommentStream cstream <- gets scCommentStream
+  case cstream of
+    [] -> return Nothing
+    (x : xs) ->
+      if f x
+        then
+          Just x
+            <$ modify
+              ( \sc ->
+                  sc
+                    { scCommentStream = CommentStream xs
+                    }
+              )
+        else return Nothing
+
+-- | Get the first enclosing 'RealSrcSpan' that satisfies given predicate.
+getEnclosingSpan ::
+  -- | Predicate to use
+  (RealSrcSpan -> Bool) ->
+  R (Maybe RealSrcSpan)
+getEnclosingSpan f =
+  listToMaybe . filter f <$> R (asks rcEnclosingSpans)
+
+-- | Set 'RealSrcSpan' of enclosing span for the given computation.
+withEnclosingSpan :: RealSrcSpan -> R () -> R ()
+withEnclosingSpan spn (R m) = R (local modRC m)
+  where
+    modRC rc =
+      rc
+        { rcEnclosingSpans = spn : rcEnclosingSpans rc
+        }
+
+-- | Haddock string style.
+data HaddockStyle
+  = -- | @-- |@
+    Pipe
+  | -- | @-- ^@
+    Caret
+  | -- | @-- *@
+    Asterisk Int
+  | -- | @-- $@
+    Named String
+
+-- | Set span of last output comment.
+setLastCommentSpan ::
+  -- | 'HaddockStyle' or 'Nothing' if it's a non-Haddock comment
+  Maybe HaddockStyle ->
+  -- | Location of last printed comment
+  RealSrcSpan ->
+  R ()
+setLastCommentSpan mhStyle spn = R . modify $ \sc ->
+  sc
+    { scLastCommentSpan = Just (mhStyle, spn)
+    }
+
+-- | Get span of last output comment.
+getLastCommentSpan :: R (Maybe (Maybe HaddockStyle, RealSrcSpan))
+getLastCommentSpan = R (gets scLastCommentSpan)
+
+----------------------------------------------------------------------------
+-- Annotations
+
+-- | For a given span return 'AnnKeywordId's associated with it.
+getAnns ::
+  SrcSpan ->
+  R [AnnKeywordId]
+getAnns spn = lookupAnns spn <$> R (asks rcAnns)
+
+----------------------------------------------------------------------------
+-- Helpers for braces
+
+-- | Make the inner computation use braces around single-line layouts.
+useBraces :: R () -> R ()
+useBraces (R r) = R (local (\i -> i {rcCanUseBraces = True}) r)
+
+-- | Make the inner computation omit braces around single-line layouts.
+dontUseBraces :: R () -> R ()
+dontUseBraces (R r) = R (local (\i -> i {rcCanUseBraces = False}) r)
+
+-- | Return 'True' if we can use braces in this context.
+canUseBraces :: R Bool
+canUseBraces = R $ asks rcCanUseBraces
+
+----------------------------------------------------------------------------
+-- Constants
+
+-- | Indentation step.
+indentStep :: Int
+indentStep = 2
diff --git a/src/Ormolu/Printer/Meat/Common.hs b/src/Ormolu/Printer/Meat/Common.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Common.hs
@@ -0,0 +1,182 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+-- | Rendering of commonly useful bits.
+module Ormolu.Printer.Meat.Common
+  ( FamilyStyle (..),
+    p_hsmodName,
+    p_ieWrappedName,
+    p_rdrName,
+    doesNotNeedExtraParens,
+    p_qualName,
+    p_infixDefHelper,
+    p_hsDocString,
+    p_hsDocName,
+  )
+where
+
+import Control.Monad
+import Data.List (isPrefixOf)
+import Data.Maybe (isJust)
+import qualified Data.Text as T
+import GHC hiding (GhcPs, IE)
+import Name (nameStableString)
+import OccName (OccName (..))
+import Ormolu.Printer.Combinators
+import Ormolu.Utils
+import RdrName (RdrName (..))
+
+-- | Data and type family style.
+data FamilyStyle
+  = -- | Declarations in type classes
+    Associated
+  | -- | Top-level declarations
+    Free
+
+p_hsmodName :: ModuleName -> R ()
+p_hsmodName mname = do
+  txt "module"
+  space
+  atom mname
+
+p_ieWrappedName :: IEWrappedName RdrName -> R ()
+p_ieWrappedName = \case
+  IEName x -> p_rdrName x
+  IEPattern x -> do
+    txt "pattern"
+    space
+    p_rdrName x
+  IEType x -> do
+    txt "type"
+    space
+    p_rdrName x
+
+-- | Render a @'Located' 'RdrName'@.
+p_rdrName :: Located RdrName -> R ()
+p_rdrName l@(L spn _) = located l $ \x -> do
+  ids <- getAnns spn
+  let backticksWrapper =
+        if AnnBackquote `elem` ids
+          then backticks
+          else id
+      parensWrapper =
+        if AnnOpenP `elem` ids
+          then parens N
+          else id
+      singleQuoteWrapper =
+        if AnnSimpleQuote `elem` ids
+          then \y -> do
+            txt "'"
+            y
+          else id
+      m =
+        case x of
+          Unqual occName ->
+            atom occName
+          Qual mname occName ->
+            p_qualName mname occName
+          Orig _ occName ->
+            -- NOTE This is used when GHC generates code that will be fed
+            -- into the renamer (e.g. from deriving clauses), but where we
+            -- want to say that something comes from given module which is
+            -- not specified in the source code, e.g. @Prelude.map@.
+            --
+            -- My current understanding is that the provided module name
+            -- serves no purpose for us and can be safely ignored.
+            atom occName
+          Exact name ->
+            atom name
+      m' = backticksWrapper (singleQuoteWrapper m)
+  if doesNotNeedExtraParens x
+    then m'
+    else parensWrapper m'
+
+-- | Whether given name should not have parentheses around it. This is used
+-- to detect e.g. tuples for which annotations will indicate parentheses,
+-- but the parentheses are already part of the symbol, so no extra layer of
+-- parentheses should be added. It also detects the [] literal.
+doesNotNeedExtraParens :: RdrName -> Bool
+doesNotNeedExtraParens = \case
+  Exact name ->
+    let s = nameStableString name
+     in -- NOTE I'm not sure this "stable string" is stable enough, but it looks
+        -- like this is the most robust way to tell if we're looking at exactly
+        -- this piece of built-in syntax.
+        ("$ghc-prim$GHC.Tuple$" `isPrefixOf` s)
+          || ("$ghc-prim$GHC.Types$[]" `isPrefixOf` s)
+  _ -> False
+
+p_qualName :: ModuleName -> OccName -> R ()
+p_qualName mname occName = do
+  atom mname
+  txt "."
+  atom occName
+
+-- | A helper for formatting infix constructions in lhs of definitions.
+p_infixDefHelper ::
+  -- | Whether to format in infix style
+  Bool ->
+  -- | Indentation-bumping wrapper
+  (R () -> R ()) ->
+  -- | How to print the operator\/name
+  R () ->
+  -- | How to print the arguments
+  [R ()] ->
+  R ()
+p_infixDefHelper isInfix inci' name args =
+  case (isInfix, args) of
+    (True, p0 : p1 : ps) -> do
+      let parens' =
+            if null ps
+              then id
+              else parens N
+      parens' $ do
+        p0
+        breakpoint
+        inci $ sitcc $ do
+          name
+          space
+          p1
+      unless (null ps) . inci' $ do
+        breakpoint
+        sitcc (sep breakpoint sitcc ps)
+    (_, ps) -> do
+      name
+      unless (null ps) $ do
+        breakpoint
+        inci' $ sitcc (sep breakpoint sitcc args)
+
+-- | Print a Haddock.
+p_hsDocString ::
+  -- | Haddock style
+  HaddockStyle ->
+  -- | Finish the doc string with a newline
+  Bool ->
+  -- | The doc string to render
+  LHsDocString ->
+  R ()
+p_hsDocString hstyle needsNewline (L l str) = do
+  goesAfterComment <- isJust <$> getLastCommentSpan
+  -- Make sure the Haddock is separated by a newline from other comments.
+  when goesAfterComment newline
+  forM_ (zip (splitDocString str) (True : repeat False)) $ \(x, isFirst) -> do
+    if isFirst
+      then case hstyle of
+        Pipe -> txt "-- |" >> space
+        Caret -> txt "-- ^" >> space
+        Asterisk n -> txt ("-- " <> T.replicate n "*") >> space
+        Named name -> p_hsDocName name
+      else newline >> txt "--" >> space
+    unless (T.null x) (txt x)
+  when needsNewline newline
+  case l of
+    UnhelpfulSpan _ ->
+      -- It's often the case that the comment itself doesn't have a span
+      -- attached to it and instead its location can be obtained from
+      -- nearest enclosing span.
+      getEnclosingSpan (const True) >>= mapM_ (setLastCommentSpan (Just hstyle))
+    RealSrcSpan spn -> setLastCommentSpan (Just hstyle) spn
+
+-- | Print anchor of named doc section.
+p_hsDocName :: String -> R ()
+p_hsDocName name = txt ("-- $" <> T.pack name)
diff --git a/src/Ormolu/Printer/Meat/Declaration.hs b/src/Ormolu/Printer/Meat/Declaration.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration.hs
@@ -0,0 +1,262 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE PatternSynonyms #-}
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE ViewPatterns #-}
+
+-- | Rendering of declarations.
+module Ormolu.Printer.Meat.Declaration
+  ( p_hsDecls,
+    hasSeparatedDecls,
+  )
+where
+
+import Data.List (sort)
+import Data.List.NonEmpty ((<|), NonEmpty (..))
+import qualified Data.List.NonEmpty as NE
+import GHC
+import OccName (occNameFS)
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import Ormolu.Printer.Meat.Declaration.Annotation
+import Ormolu.Printer.Meat.Declaration.Class
+import Ormolu.Printer.Meat.Declaration.Data
+import Ormolu.Printer.Meat.Declaration.Default
+import Ormolu.Printer.Meat.Declaration.Foreign
+import Ormolu.Printer.Meat.Declaration.Instance
+import Ormolu.Printer.Meat.Declaration.RoleAnnotation
+import Ormolu.Printer.Meat.Declaration.Rule
+import Ormolu.Printer.Meat.Declaration.Signature
+import Ormolu.Printer.Meat.Declaration.Splice
+import Ormolu.Printer.Meat.Declaration.Type
+import Ormolu.Printer.Meat.Declaration.TypeFamily
+import Ormolu.Printer.Meat.Declaration.Value
+import Ormolu.Printer.Meat.Declaration.Warning
+import Ormolu.Printer.Meat.Type
+import Ormolu.Utils
+import RdrName (rdrNameOcc)
+
+p_hsDecls :: FamilyStyle -> [LHsDecl GhcPs] -> R ()
+p_hsDecls style decls = sepSemi id $
+  -- Return a list of rendered declarations, adding a newline to separate
+  -- groups.
+  case groupDecls decls of
+    [] -> []
+    (x : xs) ->
+      NE.toList (renderGroup x)
+        ++ concatMap (NE.toList . separateGroup . renderGroup) xs
+  where
+    renderGroup = fmap (located' $ dontUseBraces . p_hsDecl style)
+    separateGroup (x :| xs) = (breakpoint' >> x) :| xs
+
+-- | Group relevant declarations together.
+--
+-- Add a declaration to a group iff it is relevant to either the first or
+-- the last declaration of the group.
+groupDecls :: [LHsDecl GhcPs] -> [NonEmpty (LHsDecl GhcPs)]
+groupDecls [] = []
+groupDecls (l@(L _ DocNext) : xs) =
+  -- If the first element is a doc string for next element, just include it
+  -- in the next block:
+  case groupDecls xs of
+    [] -> [l :| []]
+    (x : xs') -> (l <| x) : xs'
+groupDecls (lhdr : xs) =
+  let -- Pick the first decl as the group header
+      hdr = unLoc lhdr
+      -- Zip rest of the decls with their previous decl
+      zipped = zip (lhdr : xs) xs
+      -- Pick decls from the tail if they are relevant to the group header
+      -- or the previous decl.
+      (grp, rest) = flip span zipped $ \(L _ prev, L _ cur) ->
+        let relevantToHdr = groupedDecls hdr cur
+            relevantToPrev = groupedDecls prev cur
+         in relevantToHdr || relevantToPrev
+   in (lhdr :| map snd grp) : groupDecls (map snd rest)
+
+p_hsDecl :: FamilyStyle -> HsDecl GhcPs -> R ()
+p_hsDecl style = \case
+  TyClD NoExt x -> p_tyClDecl style x
+  ValD NoExt x -> p_valDecl x
+  SigD NoExt x -> p_sigDecl x
+  InstD NoExt x -> p_instDecl style x
+  DerivD NoExt x -> p_derivDecl x
+  DefD NoExt x -> p_defaultDecl x
+  ForD NoExt x -> p_foreignDecl x
+  WarningD NoExt x -> p_warnDecls x
+  AnnD NoExt x -> p_annDecl x
+  RuleD NoExt x -> p_ruleDecls x
+  SpliceD NoExt x -> p_spliceDecl x
+  DocD NoExt docDecl ->
+    case docDecl of
+      DocCommentNext str -> p_hsDocString Pipe False (noLoc str)
+      DocCommentPrev str -> p_hsDocString Caret False (noLoc str)
+      DocCommentNamed name str -> p_hsDocString (Named name) False (noLoc str)
+      DocGroup n str -> p_hsDocString (Asterisk n) False (noLoc str)
+  RoleAnnotD NoExt x -> p_roleAnnot x
+  XHsDecl _ -> notImplemented "XHsDecl"
+
+p_tyClDecl :: FamilyStyle -> TyClDecl GhcPs -> R ()
+p_tyClDecl style = \case
+  FamDecl NoExt x -> p_famDecl style x
+  SynDecl {..} -> p_synDecl tcdLName tcdFixity tcdTyVars tcdRhs
+  DataDecl {..} ->
+    p_dataDecl
+      Associated
+      tcdLName
+      (tyVarsToTypes tcdTyVars)
+      tcdFixity
+      tcdDataDefn
+  ClassDecl {..} ->
+    p_classDecl
+      tcdCtxt
+      tcdLName
+      tcdTyVars
+      tcdFixity
+      tcdFDs
+      tcdSigs
+      tcdMeths
+      tcdATs
+      tcdATDefs
+      tcdDocs
+  XTyClDecl {} -> notImplemented "XTyClDecl"
+
+p_instDecl :: FamilyStyle -> InstDecl GhcPs -> R ()
+p_instDecl style = \case
+  ClsInstD NoExt x -> p_clsInstDecl x
+  TyFamInstD NoExt x -> p_tyFamInstDecl style x
+  DataFamInstD NoExt x -> p_dataFamInstDecl style x
+  XInstDecl _ -> notImplemented "XInstDecl"
+
+p_derivDecl :: DerivDecl GhcPs -> R ()
+p_derivDecl = \case
+  d@DerivDecl {..} -> p_standaloneDerivDecl d
+  XDerivDecl _ -> notImplemented "XDerivDecl standalone deriving"
+
+-- | Determine if these declarations should be grouped together.
+groupedDecls ::
+  HsDecl GhcPs ->
+  HsDecl GhcPs ->
+  Bool
+groupedDecls (TypeSignature ns) (FunctionBody ns') = ns `intersects` ns'
+groupedDecls x (FunctionBody ns) | Just ns' <- isPragma x = ns `intersects` ns'
+groupedDecls (FunctionBody ns) x | Just ns' <- isPragma x = ns `intersects` ns'
+groupedDecls x (DataDeclaration n) | Just ns <- isPragma x = n `elem` ns
+groupedDecls (DataDeclaration n) x
+  | Just ns <- isPragma x =
+    let f = occNameFS . rdrNameOcc in f n `elem` map f ns
+groupedDecls x y | Just ns <- isPragma x, Just ns' <- isPragma y = ns `intersects` ns'
+groupedDecls x (TypeSignature ns) | Just ns' <- isPragma x = ns `intersects` ns'
+groupedDecls (TypeSignature ns) x | Just ns' <- isPragma x = ns `intersects` ns'
+groupedDecls (PatternSignature ns) (Pattern n) = n `elem` ns
+groupedDecls DocNext _ = True
+groupedDecls _ DocPrev = True
+groupedDecls _ _ = False
+
+intersects :: Ord a => [a] -> [a] -> Bool
+intersects a b = go (sort a) (sort b)
+  where
+    go :: Ord a => [a] -> [a] -> Bool
+    go _ [] = False
+    go [] _ = False
+    go (x : xs) (y : ys)
+      | x < y = go xs (y : ys)
+      | x > y = go (x : xs) ys
+      | otherwise = True
+
+-- | Checks if given list of declarations contain a pair which should
+-- be separated by a blank line.
+hasSeparatedDecls :: [LHsDecl GhcPs] -> Bool
+hasSeparatedDecls xs = case groupDecls xs of
+  _ : _ : _ -> True
+  _ -> False
+
+isPragma ::
+  HsDecl GhcPs ->
+  Maybe [RdrName]
+isPragma = \case
+  InlinePragma n -> Just [n]
+  SpecializePragma n -> Just [n]
+  SCCPragma n -> Just [n]
+  AnnTypePragma n -> Just [n]
+  AnnValuePragma n -> Just [n]
+  WarningPragma n -> Just n
+  _ -> Nothing
+
+-- Declarations referring to a single name
+
+pattern
+  InlinePragma,
+  SpecializePragma,
+  SCCPragma,
+  AnnTypePragma,
+  AnnValuePragma,
+  Pattern,
+  DataDeclaration ::
+    RdrName -> HsDecl GhcPs
+pattern InlinePragma n <- SigD NoExt (InlineSig NoExt (L _ n) _)
+pattern SpecializePragma n <- SigD NoExt (SpecSig NoExt (L _ n) _ _)
+pattern SCCPragma n <- SigD NoExt (SCCFunSig NoExt _ (L _ n) _)
+pattern AnnTypePragma n <- AnnD NoExt (HsAnnotation NoExt _ (TypeAnnProvenance (L _ n)) _)
+pattern AnnValuePragma n <- AnnD NoExt (HsAnnotation NoExt _ (ValueAnnProvenance (L _ n)) _)
+pattern Pattern n <- ValD NoExt (PatSynBind NoExt (PSB _ (L _ n) _ _ _))
+pattern DataDeclaration n <- TyClD NoExt (DataDecl NoExt (L _ n) _ _ _)
+
+-- Declarations which can refer to multiple names
+
+pattern
+  TypeSignature,
+  FunctionBody,
+  PatternSignature,
+  WarningPragma ::
+    [RdrName] -> HsDecl GhcPs
+pattern TypeSignature n <- (sigRdrNames -> Just n)
+pattern FunctionBody n <- (funRdrNames -> Just n)
+pattern PatternSignature n <- (patSigRdrNames -> Just n)
+pattern WarningPragma n <- (warnSigRdrNames -> Just n)
+
+pattern DocNext, DocPrev :: HsDecl GhcPs
+pattern DocNext <- (DocD NoExt (DocCommentNext _))
+pattern DocPrev <- (DocD NoExt (DocCommentPrev _))
+
+sigRdrNames :: HsDecl GhcPs -> Maybe [RdrName]
+sigRdrNames (SigD NoExt (TypeSig NoExt ns _)) = Just $ map unLoc ns
+sigRdrNames (SigD NoExt (ClassOpSig NoExt _ ns _)) = Just $ map unLoc ns
+sigRdrNames (SigD NoExt (PatSynSig NoExt ns _)) = Just $ map unLoc ns
+sigRdrNames _ = Nothing
+
+funRdrNames :: HsDecl GhcPs -> Maybe [RdrName]
+funRdrNames (ValD NoExt (FunBind NoExt (L _ n) _ _ _)) = Just [n]
+funRdrNames (ValD NoExt (PatBind NoExt (L _ n) _ _)) = Just $ patBindNames n
+funRdrNames _ = Nothing
+
+patSigRdrNames :: HsDecl GhcPs -> Maybe [RdrName]
+patSigRdrNames (SigD NoExt (PatSynSig NoExt ns _)) = Just $ map unLoc ns
+patSigRdrNames _ = Nothing
+
+warnSigRdrNames :: HsDecl GhcPs -> Maybe [RdrName]
+warnSigRdrNames (WarningD NoExt (Warnings NoExt _ ws)) = Just $ flip concatMap ws $ \case
+  L _ (Warning NoExt ns _) -> map unLoc ns
+  L _ (XWarnDecl NoExt) -> []
+warnSigRdrNames _ = Nothing
+
+patBindNames :: Pat GhcPs -> [RdrName]
+patBindNames (TuplePat NoExt ps _) = concatMap (patBindNames . unLoc) ps
+patBindNames (VarPat NoExt (L _ n)) = [n]
+patBindNames (WildPat NoExt) = []
+patBindNames (LazyPat NoExt (L _ p)) = patBindNames p
+patBindNames (BangPat NoExt (L _ p)) = patBindNames p
+patBindNames (ParPat NoExt (L _ p)) = patBindNames p
+patBindNames (ListPat NoExt ps) = concatMap (patBindNames . unLoc) ps
+patBindNames (AsPat NoExt (L _ n) (L _ p)) = n : patBindNames p
+patBindNames (SumPat NoExt (L _ p) _ _) = patBindNames p
+patBindNames (ViewPat NoExt _ (L _ p)) = patBindNames p
+patBindNames (SplicePat NoExt _) = []
+patBindNames (LitPat NoExt _) = []
+patBindNames (SigPat _ (L _ p)) = patBindNames p
+patBindNames (NPat NoExt _ _ _) = []
+patBindNames (NPlusKPat NoExt (L _ n) _ _ _ _) = [n]
+patBindNames (ConPatIn _ d) = concatMap (patBindNames . unLoc) (hsConPatArgs d)
+patBindNames (ConPatOut _ _ _ _ _ _ _) = notImplemented "ConPatOut" -- created by renamer
+patBindNames (CoPat NoExt _ p _) = patBindNames p
+patBindNames (XPat NoExt) = notImplemented "XPat"
diff --git a/src/Ormolu/Printer/Meat/Declaration.hs-boot b/src/Ormolu/Printer/Meat/Declaration.hs-boot
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration.hs-boot
@@ -0,0 +1,13 @@
+module Ormolu.Printer.Meat.Declaration
+  ( p_hsDecls,
+    hasSeparatedDecls,
+  )
+where
+
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+
+p_hsDecls :: FamilyStyle -> [LHsDecl GhcPs] -> R ()
+
+hasSeparatedDecls :: [LHsDecl GhcPs] -> Bool
diff --git a/src/Ormolu/Printer/Meat/Declaration/Annotation.hs b/src/Ormolu/Printer/Meat/Declaration/Annotation.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Annotation.hs
@@ -0,0 +1,27 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+module Ormolu.Printer.Meat.Declaration.Annotation
+  ( p_annDecl,
+  )
+where
+
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import Ormolu.Printer.Meat.Declaration.Value
+import Ormolu.Utils
+
+p_annDecl :: AnnDecl GhcPs -> R ()
+p_annDecl = \case
+  HsAnnotation NoExt _ annProv expr -> pragma "ANN" . inci $ do
+    p_annProv annProv
+    breakpoint
+    located expr p_hsExpr
+  XAnnDecl {} -> notImplemented "XAnnDecl"
+
+p_annProv :: AnnProvenance (IdP GhcPs) -> R ()
+p_annProv = \case
+  ValueAnnProvenance name -> p_rdrName name
+  TypeAnnProvenance name -> txt "type" >> space >> p_rdrName name
+  ModuleAnnProvenance -> txt "module"
diff --git a/src/Ormolu/Printer/Meat/Declaration/Class.hs b/src/Ormolu/Printer/Meat/Declaration/Class.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Class.hs
@@ -0,0 +1,113 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Rendering of type class declarations.
+module Ormolu.Printer.Meat.Declaration.Class
+  ( p_classDecl,
+  )
+where
+
+import Class
+import Control.Arrow
+import Control.Monad
+import Data.Foldable
+import Data.List (sortBy)
+import Data.Ord (comparing)
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import {-# SOURCE #-} Ormolu.Printer.Meat.Declaration
+import Ormolu.Printer.Meat.Type
+import Ormolu.Utils
+import RdrName (RdrName (..))
+
+p_classDecl ::
+  LHsContext GhcPs ->
+  Located RdrName ->
+  LHsQTyVars GhcPs ->
+  LexicalFixity ->
+  [Located (FunDep (Located RdrName))] ->
+  [LSig GhcPs] ->
+  LHsBinds GhcPs ->
+  [LFamilyDecl GhcPs] ->
+  [LTyFamDefltEqn GhcPs] ->
+  [LDocDecl] ->
+  R ()
+p_classDecl ctx name tvars fixity fdeps csigs cdefs cats catdefs cdocs = do
+  let HsQTvs {..} = tvars
+      variableSpans = getLoc <$> hsq_explicit
+      signatureSpans = getLoc name : variableSpans
+      dependencySpans = getLoc <$> fdeps
+      combinedSpans = getLoc ctx : (signatureSpans ++ dependencySpans)
+  txt "class"
+  switchLayout combinedSpans $ do
+    breakpoint
+    inci $ do
+      p_classContext ctx
+      switchLayout signatureSpans $ do
+        p_infixDefHelper
+          (isInfix fixity)
+          inci
+          (p_rdrName name)
+          (located' p_hsTyVarBndr <$> hsq_explicit)
+      inci (p_classFundeps fdeps)
+  -- NOTE GHC's AST does not necessarily store each kind of element in
+  -- source location order. This happens because different declarations are
+  -- stored in different lists. Consequently, to get all the declarations in
+  -- proper order, they need to be manually sorted.
+  let sigs = (getLoc &&& fmap (SigD NoExt)) <$> csigs
+      vals = (getLoc &&& fmap (ValD NoExt)) <$> toList cdefs
+      tyFams = (getLoc &&& fmap (TyClD NoExt . FamDecl NoExt)) <$> cats
+      docs = (getLoc &&& fmap (DocD NoExt)) <$> cdocs
+      tyFamDefs =
+        ( getLoc &&& fmap (InstD NoExt . TyFamInstD NoExt . defltEqnToInstDecl)
+        )
+          <$> catdefs
+      allDecls =
+        snd <$> sortBy (comparing fst) (sigs <> vals <> tyFams <> tyFamDefs <> docs)
+  unless (null allDecls) $ do
+    space
+    txt "where"
+    breakpoint -- Ensure whitespace is added after where clause.
+    -- Add newline before first declaration if the body contains separate
+    -- declarations.
+    when (hasSeparatedDecls allDecls) breakpoint'
+    inci (p_hsDecls Associated allDecls)
+
+p_classContext :: LHsContext GhcPs -> R ()
+p_classContext ctx = unless (null (unLoc ctx)) $ do
+  located ctx p_hsContext
+  space
+  txt "=>"
+  breakpoint
+
+p_classFundeps :: [Located (FunDep (Located RdrName))] -> R ()
+p_classFundeps fdeps = unless (null fdeps) $ do
+  breakpoint
+  txt "|"
+  space
+  sitcc $ sep (comma >> breakpoint) (sitcc . located' p_funDep) fdeps
+
+p_funDep :: FunDep (Located RdrName) -> R ()
+p_funDep (before, after) = do
+  sep space p_rdrName before
+  space
+  txt "->"
+  space
+  sep space p_rdrName after
+
+----------------------------------------------------------------------------
+-- Helpers
+
+defltEqnToInstDecl :: TyFamDefltEqn GhcPs -> TyFamInstDecl GhcPs
+defltEqnToInstDecl FamEqn {..} = TyFamInstDecl {..}
+  where
+    eqn = FamEqn {feqn_pats = tyVarsToTypes feqn_pats, ..}
+    tfid_eqn = HsIB {hsib_ext = NoExt, hsib_body = eqn}
+defltEqnToInstDecl XFamEqn {} = notImplemented "XFamEqn"
+
+isInfix :: LexicalFixity -> Bool
+isInfix = \case
+  Infix -> True
+  Prefix -> False
diff --git a/src/Ormolu/Printer/Meat/Declaration/Data.hs b/src/Ormolu/Printer/Meat/Declaration/Data.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Data.hs
@@ -0,0 +1,245 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Renedring of data type declarations.
+module Ormolu.Printer.Meat.Declaration.Data
+  ( p_dataDecl,
+  )
+where
+
+import Control.Monad
+import Data.Maybe (isJust)
+import Data.Maybe (maybeToList)
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import Ormolu.Printer.Meat.Type
+import Ormolu.Utils
+import RdrName (RdrName (..))
+import SrcLoc (Located)
+
+p_dataDecl ::
+  -- | Whether to format as data family
+  FamilyStyle ->
+  -- | Type constructor
+  Located RdrName ->
+  -- | Type patterns
+  [LHsType GhcPs] ->
+  -- | Lexical fixity
+  LexicalFixity ->
+  -- | Data definition
+  HsDataDefn GhcPs ->
+  R ()
+p_dataDecl style name tpats fixity HsDataDefn {..} = do
+  txt $ case dd_ND of
+    NewType -> "newtype"
+    DataType -> "data"
+  txt $ case style of
+    Associated -> mempty
+    Free -> " instance"
+  switchLayout (getLoc name : fmap getLoc tpats) $ do
+    breakpoint
+    inci $
+      p_infixDefHelper
+        (isInfix fixity)
+        inci
+        (p_rdrName name)
+        (located' p_hsType <$> tpats)
+  case dd_kindSig of
+    Nothing -> return ()
+    Just k -> do
+      space
+      txt "::"
+      space
+      located k p_hsType
+  let gadt = isJust dd_kindSig || any (isGadt . unLoc) dd_cons
+  unless (null dd_cons) $
+    if gadt
+      then do
+        space
+        txt "where"
+        breakpoint
+        inci $ sepSemi (located' p_conDecl) dd_cons
+      else switchLayout (getLoc name : (getLoc <$> dd_cons))
+        $ inci
+        $ do
+          breakpoint
+          txt "="
+          space
+          let s =
+                vlayout
+                  (space >> txt "|" >> space)
+                  (newline >> txt "|" >> space)
+          sep s (sitcc . located' p_conDecl) dd_cons
+  unless (null $ unLoc dd_derivs) breakpoint
+  inci . located dd_derivs $ \xs -> do
+    sep newline (located' p_hsDerivingClause) xs
+p_dataDecl _ _ _ _ (XHsDataDefn NoExt) = notImplemented "XHsDataDefn"
+
+p_conDecl :: ConDecl GhcPs -> R ()
+p_conDecl = \case
+  ConDeclGADT {..} -> do
+    mapM_ (p_hsDocString Pipe True) con_doc
+    let conDeclSpn =
+          fmap getLoc con_names
+            <> [getLoc con_forall]
+            <> conTyVarsSpans con_qvars
+            <> maybeToList (fmap getLoc con_mb_cxt)
+            <> conArgsSpans con_args
+    switchLayout conDeclSpn $ do
+      case con_names of
+        [] -> return ()
+        (c : cs) -> do
+          p_rdrName c
+          unless (null cs) . inci $ do
+            comma
+            breakpoint
+            sitcc $ sep (comma >> breakpoint) p_rdrName cs
+      space
+      inci $ do
+        txt "::"
+        let interArgBreak =
+              if hasDocStrings (unLoc con_res_ty)
+                then newline
+                else breakpoint
+        interArgBreak
+        p_forallBndrs (hsq_explicit con_qvars)
+        unless (null $ hsq_explicit con_qvars) interArgBreak
+        forM_ con_mb_cxt p_lhsContext
+        case con_args of
+          PrefixCon xs -> do
+            sep breakpoint (located' p_hsType) xs
+            unless (null xs) $ do
+              space
+              txt "->"
+              breakpoint
+          RecCon l -> do
+            located l p_conDeclFields
+            unless (null $ unLoc l) $ do
+              space
+              txt "->"
+              breakpoint
+          InfixCon _ _ -> notImplemented "InfixCon"
+        p_hsType (unLoc con_res_ty)
+  ConDeclH98 {..} -> do
+    mapM_ (p_hsDocString Pipe True) con_doc
+    let conDeclSpn =
+          [getLoc con_name]
+            <> fmap getLoc con_ex_tvs
+            <> maybeToList (fmap getLoc con_mb_cxt)
+            <> conArgsSpans con_args
+    switchLayout conDeclSpn $ do
+      p_forallBndrs con_ex_tvs
+      unless (null con_ex_tvs) breakpoint
+      forM_ con_mb_cxt p_lhsContext
+      case con_args of
+        PrefixCon xs -> do
+          p_rdrName con_name
+          unless (null xs) breakpoint
+          inci . sitcc $ sep breakpoint (sitcc . located' p_hsType) xs
+        RecCon l -> do
+          p_rdrName con_name
+          breakpoint
+          inci $ located l p_conDeclFields
+        InfixCon x y -> do
+          located x p_hsType
+          breakpoint
+          inci $ do
+            p_rdrName con_name
+            space
+            located y p_hsType
+  XConDecl NoExt -> notImplemented "XConDecl"
+
+conArgsSpans :: HsConDeclDetails GhcPs -> [SrcSpan]
+conArgsSpans = \case
+  PrefixCon xs ->
+    getLoc <$> xs
+  RecCon l ->
+    [getLoc l]
+  InfixCon x y ->
+    [getLoc x, getLoc y]
+
+conTyVarsSpans :: LHsQTyVars GhcPs -> [SrcSpan]
+conTyVarsSpans = \case
+  HsQTvs {..} -> getLoc <$> hsq_explicit
+  XLHsQTyVars NoExt -> []
+
+p_forallBndrs ::
+  [LHsTyVarBndr GhcPs] ->
+  R ()
+p_forallBndrs = \case
+  [] -> return ()
+  bndrs -> do
+    txt "forall"
+    space
+    sep space (located' p_hsTyVarBndr) bndrs
+    txt "."
+
+p_lhsContext ::
+  LHsContext GhcPs ->
+  R ()
+p_lhsContext = \case
+  L _ [] -> pure ()
+  ctx -> do
+    located ctx p_hsContext
+    space
+    txt "=>"
+    breakpoint
+
+isGadt :: ConDecl GhcPs -> Bool
+isGadt = \case
+  ConDeclGADT {} -> True
+  ConDeclH98 {} -> False
+  XConDecl {} -> False
+
+p_hsDerivingClause ::
+  HsDerivingClause GhcPs ->
+  R ()
+p_hsDerivingClause HsDerivingClause {..} = do
+  txt "deriving"
+  let derivingWhat = located deriv_clause_tys $ \case
+        [] -> txt "()"
+        xs ->
+          parens N . sitcc $
+            sep
+              (comma >> breakpoint)
+              (sitcc . located' p_hsType . hsib_body)
+              xs
+  space
+  case deriv_clause_strategy of
+    Nothing -> do
+      breakpoint
+      inci derivingWhat
+    Just (L _ a) -> case a of
+      StockStrategy -> do
+        txt "stock"
+        breakpoint
+        inci derivingWhat
+      AnyclassStrategy -> do
+        txt "anyclass"
+        breakpoint
+        inci derivingWhat
+      NewtypeStrategy -> do
+        txt "newtype"
+        breakpoint
+        inci derivingWhat
+      ViaStrategy HsIB {..} -> do
+        breakpoint
+        inci $ do
+          derivingWhat
+          breakpoint
+          txt "via"
+          space
+          located hsib_body p_hsType
+      ViaStrategy (XHsImplicitBndrs NoExt) ->
+        notImplemented "XHsImplicitBndrs"
+p_hsDerivingClause (XHsDerivingClause NoExt) = notImplemented "XHsDerivingClause"
+
+----------------------------------------------------------------------------
+-- Helpers
+
+isInfix :: LexicalFixity -> Bool
+isInfix = \case
+  Infix -> True
+  Prefix -> False
diff --git a/src/Ormolu/Printer/Meat/Declaration/Default.hs b/src/Ormolu/Printer/Meat/Declaration/Default.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Default.hs
@@ -0,0 +1,21 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+module Ormolu.Printer.Meat.Declaration.Default
+  ( p_defaultDecl,
+  )
+where
+
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Type
+import Ormolu.Utils
+
+p_defaultDecl :: DefaultDecl GhcPs -> R ()
+p_defaultDecl = \case
+  DefaultDecl NoExt ts -> do
+    txt "default"
+    breakpoint
+    inci . parens N . sitcc $
+      sep (comma >> breakpoint) (sitcc . located' p_hsType) ts
+  XDefaultDecl {} -> notImplemented "XDefaultDecl"
diff --git a/src/Ormolu/Printer/Meat/Declaration/Foreign.hs b/src/Ormolu/Printer/Meat/Declaration/Foreign.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Foreign.hs
@@ -0,0 +1,72 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+module Ormolu.Printer.Meat.Declaration.Foreign
+  ( p_foreignDecl,
+  )
+where
+
+import BasicTypes
+import Control.Monad
+import Data.Text
+import ForeignCall
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import Ormolu.Printer.Meat.Declaration.Signature
+import Ormolu.Utils
+
+p_foreignDecl :: ForeignDecl GhcPs -> R ()
+p_foreignDecl = \case
+  fd@ForeignImport {fd_fi} -> do
+    p_foreignImport fd_fi
+    p_foreignTypeSig fd
+  fd@ForeignExport {fd_fe} -> do
+    p_foreignExport fd_fe
+    p_foreignTypeSig fd
+  XForeignDecl {} -> notImplemented "XForeignDecl"
+
+-- | Printer for the last part of an import\/export, which is function name
+-- and type signature.
+p_foreignTypeSig :: ForeignDecl GhcPs -> R ()
+p_foreignTypeSig fd = do
+  breakpoint
+  -- Switch into the layout of the signature, to allow us to pull name and
+  -- signature onto a single line.
+  inci . switchLayout [getLoc . hsib_body $ fd_sig_ty fd] $ do
+    p_rdrName (fd_name fd)
+    p_typeAscription (HsWC NoExt (fd_sig_ty fd))
+
+-- | Printer for 'ForeignImport'.
+--
+-- These have the form:
+--
+-- > foreign import callingConvention [safety] [identifier]
+--
+-- We need to check whether the safety has a good source, span, as it
+-- defaults to 'PlaySafe' if you don't have anything in the source.
+--
+-- We also layout the identifier using the 'SourceText', because printing
+-- with the other two fields of 'CImport' is very complicated. See the
+-- 'Outputable' instance of 'ForeignImport' for details.
+p_foreignImport :: ForeignImport -> R ()
+p_foreignImport (CImport cCallConv safety _ _ sourceText) = do
+  txt "foreign import"
+  space
+  located cCallConv atom
+  -- Need to check for 'noLoc' for the 'safe' annotation
+  when (isGoodSrcSpan $ getLoc safety) (space >> atom safety)
+  located sourceText p_sourceText
+
+p_foreignExport :: ForeignExport -> R ()
+p_foreignExport (CExport (L loc (CExportStatic _ _ cCallConv)) sourceText) = do
+  txt "foreign export"
+  space
+  located (L loc cCallConv) atom
+  located sourceText p_sourceText
+
+p_sourceText :: SourceText -> R ()
+p_sourceText = \case
+  NoSourceText -> pure ()
+  SourceText s -> space >> txt (pack s)
diff --git a/src/Ormolu/Printer/Meat/Declaration/Instance.hs b/src/Ormolu/Printer/Meat/Declaration/Instance.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Instance.hs
@@ -0,0 +1,137 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Type class, type family, and data family instance declarations.
+module Ormolu.Printer.Meat.Declaration.Instance
+  ( p_clsInstDecl,
+    p_tyFamInstDecl,
+    p_dataFamInstDecl,
+    p_standaloneDerivDecl,
+  )
+where
+
+import BasicTypes
+import Control.Arrow
+import Control.Monad
+import Data.Foldable
+import Data.List (sortBy)
+import Data.Ord (comparing)
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import {-# SOURCE #-} Ormolu.Printer.Meat.Declaration
+import Ormolu.Printer.Meat.Declaration.Data
+import Ormolu.Printer.Meat.Declaration.TypeFamily
+import Ormolu.Printer.Meat.Type
+import Ormolu.Utils
+
+p_standaloneDerivDecl :: DerivDecl GhcPs -> R ()
+p_standaloneDerivDecl DerivDecl {..} = do
+  let typesAfterInstance = located (hsib_body (hswc_body deriv_type)) p_hsType
+      instTypes toIndent = inci $ do
+        txt "instance"
+        breakpoint
+        match_overlap_mode deriv_overlap_mode breakpoint
+        if toIndent
+          then inci typesAfterInstance
+          else typesAfterInstance
+  txt "deriving"
+  space
+  case deriv_strategy of
+    Nothing -> do
+      instTypes False
+    Just (L _ a) -> case a of
+      StockStrategy -> do
+        txt "stock "
+        instTypes False
+      AnyclassStrategy -> do
+        txt "anyclass "
+        instTypes False
+      NewtypeStrategy -> do
+        txt "newtype "
+        instTypes False
+      ViaStrategy HsIB {..} -> do
+        txt "via"
+        breakpoint
+        inci (located hsib_body p_hsType)
+        breakpoint
+        instTypes True
+      ViaStrategy (XHsImplicitBndrs NoExt) ->
+        notImplemented "XHsImplicitBndrs"
+p_standaloneDerivDecl (XDerivDecl _) = notImplemented "XDerivDecl"
+
+p_clsInstDecl :: ClsInstDecl GhcPs -> R ()
+p_clsInstDecl = \case
+  ClsInstDecl {..} -> do
+    txt "instance"
+    case cid_poly_ty of
+      HsIB {..} -> do
+        -- GHC's AST does not necessarily store each kind of element in source
+        -- location order. This happens because different declarations are stored in
+        -- different lists. Consequently, to get all the declarations in proper
+        -- order, they need to be manually sorted.
+        let sigs = (getLoc &&& fmap (SigD NoExt)) <$> cid_sigs
+            vals = (getLoc &&& fmap (ValD NoExt)) <$> toList cid_binds
+            tyFamInsts =
+              ( getLoc &&& fmap (InstD NoExt . TyFamInstD NoExt)
+              )
+                <$> cid_tyfam_insts
+            dataFamInsts =
+              ( getLoc &&& fmap (InstD NoExt . DataFamInstD NoExt)
+              )
+                <$> cid_datafam_insts
+            allDecls =
+              snd
+                <$> sortBy (comparing fst) (sigs <> vals <> tyFamInsts <> dataFamInsts)
+        located hsib_body $ \x -> do
+          breakpoint
+          inci $ do
+            match_overlap_mode cid_overlap_mode breakpoint
+            p_hsType x
+            unless (null allDecls) $ do
+              breakpoint
+              txt "where"
+        unless (null allDecls) $ do
+          inci $ do
+            -- Ensure whitespace is added after where clause.
+            breakpoint
+            -- Add newline before first declaration if the body contains separate
+            -- declarations
+            when (hasSeparatedDecls allDecls) breakpoint'
+            dontUseBraces $ p_hsDecls Associated allDecls
+      XHsImplicitBndrs NoExt -> notImplemented "XHsImplicitBndrs"
+  XClsInstDecl NoExt -> notImplemented "XClsInstDecl"
+
+p_tyFamInstDecl :: FamilyStyle -> TyFamInstDecl GhcPs -> R ()
+p_tyFamInstDecl style = \case
+  TyFamInstDecl {..} -> do
+    txt $ case style of
+      Associated -> "type"
+      Free -> "type instance"
+    breakpoint
+    inci (p_tyFamInstEqn tfid_eqn)
+
+p_dataFamInstDecl :: FamilyStyle -> DataFamInstDecl GhcPs -> R ()
+p_dataFamInstDecl style = \case
+  DataFamInstDecl {..} -> do
+    let HsIB {..} = dfid_eqn
+        FamEqn {..} = hsib_body
+    p_dataDecl style feqn_tycon feqn_pats feqn_fixity feqn_rhs
+
+match_overlap_mode :: Maybe (Located OverlapMode) -> R () -> R ()
+match_overlap_mode overlap_mode layoutStrategy =
+  case unLoc <$> overlap_mode of
+    Just Overlappable {} -> do
+      txt "{-# OVERLAPPABLE #-}"
+      layoutStrategy
+    Just Overlapping {} -> do
+      txt "{-# OVERLAPPING #-}"
+      layoutStrategy
+    Just Overlaps {} -> do
+      txt "{-# OVERLAPS #-}"
+      layoutStrategy
+    Just Incoherent {} -> do
+      txt "{-# INCOHERENT #-}"
+      layoutStrategy
+    _ -> pure ()
diff --git a/src/Ormolu/Printer/Meat/Declaration/RoleAnnotation.hs b/src/Ormolu/Printer/Meat/Declaration/RoleAnnotation.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/RoleAnnotation.hs
@@ -0,0 +1,39 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE TypeFamilies #-}
+
+-- | Rendering of Role annotation declarations.
+module Ormolu.Printer.Meat.Declaration.RoleAnnotation
+  ( p_roleAnnot,
+  )
+where
+
+import CoAxiom
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import Ormolu.Utils
+import RdrName (RdrName (..))
+import SrcLoc (Located)
+
+p_roleAnnot :: RoleAnnotDecl GhcPs -> R ()
+p_roleAnnot = \case
+  RoleAnnotDecl NoExt l_name anns -> p_roleAnnot' l_name anns
+  XRoleAnnotDecl _ -> notImplemented "XRoleAnnotDecl"
+
+p_roleAnnot' :: Located RdrName -> [Located (Maybe Role)] -> R ()
+p_roleAnnot' l_name anns = do
+  txt "type role"
+  breakpoint
+  inci $ do
+    p_rdrName l_name
+    breakpoint
+    let p_role' = maybe (txt "_") p_role
+    inci . sitcc $ sep breakpoint (sitcc . located' p_role') anns
+
+p_role :: Role -> R ()
+p_role = \case
+  Nominal -> txt "nominal"
+  Representational -> txt "representational"
+  Phantom -> txt "phantom"
diff --git a/src/Ormolu/Printer/Meat/Declaration/Rule.hs b/src/Ormolu/Printer/Meat/Declaration/Rule.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Rule.hs
@@ -0,0 +1,62 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+module Ormolu.Printer.Meat.Declaration.Rule
+  ( p_ruleDecls,
+  )
+where
+
+import BasicTypes
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import Ormolu.Printer.Meat.Declaration.Signature
+import Ormolu.Printer.Meat.Declaration.Value
+import Ormolu.Utils
+
+p_ruleDecls :: RuleDecls GhcPs -> R ()
+p_ruleDecls = \case
+  HsRules NoExt _ xs ->
+    pragma "RULES" . sitcc $
+      sep breakpoint (sitcc . located' p_ruleDecl) xs
+  XRuleDecls NoExt -> notImplemented "XRuleDecls"
+
+p_ruleDecl :: RuleDecl GhcPs -> R ()
+p_ruleDecl = \case
+  HsRule NoExt ruleName activation ruleBndrs lhs rhs -> do
+    located ruleName p_ruleName
+    space
+    p_activation activation
+    space
+    p_ruleBndrs ruleBndrs
+    breakpoint
+    inci $ do
+      located lhs p_hsExpr
+      space
+      txt "="
+      inci $ do
+        breakpoint
+        located rhs p_hsExpr
+  XRuleDecl NoExt -> notImplemented "XRuleDecl"
+
+p_ruleName :: (SourceText, RuleName) -> R ()
+p_ruleName (_, name) = atom $ HsString NoSourceText name
+
+p_ruleBndrs :: [LRuleBndr GhcPs] -> R ()
+p_ruleBndrs [] = return ()
+p_ruleBndrs bndrs =
+  switchLayout (getLoc <$> bndrs) $ do
+    txt "forall"
+    breakpoint
+    inci $ do
+      sitcc $ sep breakpoint (sitcc . located' p_ruleBndr) bndrs
+      txt "."
+
+p_ruleBndr :: RuleBndr GhcPs -> R ()
+p_ruleBndr = \case
+  RuleBndr NoExt x -> p_rdrName x
+  RuleBndrSig NoExt x hswc -> parens N $ do
+    p_rdrName x
+    p_typeAscription hswc
+  XRuleBndr NoExt -> notImplemented "XRuleBndr"
diff --git a/src/Ormolu/Printer/Meat/Declaration/Signature.hs b/src/Ormolu/Printer/Meat/Declaration/Signature.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Signature.hs
@@ -0,0 +1,220 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Type signature declarations.
+module Ormolu.Printer.Meat.Declaration.Signature
+  ( p_sigDecl,
+    p_typeAscription,
+    p_activation,
+  )
+where
+
+import BasicTypes
+import BooleanFormula
+import Control.Monad
+import Data.Bool (bool)
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import Ormolu.Printer.Meat.Type
+import Ormolu.Utils
+
+p_sigDecl :: Sig GhcPs -> R ()
+p_sigDecl = \case
+  TypeSig NoExt names hswc -> p_typeSig True names hswc
+  PatSynSig NoExt names hsib -> p_patSynSig names hsib
+  ClassOpSig NoExt def names hsib -> p_classOpSig def names hsib
+  FixSig NoExt sig -> p_fixSig sig
+  InlineSig NoExt name inlinePragma -> p_inlineSig name inlinePragma
+  SpecSig NoExt name ts inlinePragma -> p_specSig name ts inlinePragma
+  SpecInstSig NoExt _ hsib -> p_specInstSig hsib
+  MinimalSig NoExt _ booleanFormula -> p_minimalSig booleanFormula
+  CompleteMatchSig NoExt _sourceText cs ty -> p_completeSig cs ty
+  SCCFunSig NoExt _ name literal -> p_sccSig name literal
+  _ -> notImplemented "certain types of signature declarations"
+
+p_typeSig ::
+  -- | Should the tail of the names be indented
+  Bool ->
+  -- | Names (before @::@)
+  [Located RdrName] ->
+  -- | Type
+  LHsSigWcType GhcPs ->
+  R ()
+p_typeSig _ [] _ = return () -- should not happen though
+p_typeSig indentTail (n : ns) hswc = do
+  p_rdrName n
+  if null ns
+    then p_typeAscription hswc
+    else bool id inci indentTail $ do
+      comma
+      breakpoint
+      sep (comma >> breakpoint) p_rdrName ns
+      p_typeAscription hswc
+
+p_typeAscription ::
+  LHsSigWcType GhcPs ->
+  R ()
+p_typeAscription HsWC {..} = do
+  space
+  inci $ do
+    txt "::"
+    let t = hsib_body hswc_body
+    if hasDocStrings (unLoc t)
+      then newline
+      else breakpoint
+    located t p_hsType
+p_typeAscription (XHsWildCardBndrs NoExt) = notImplemented "XHsWildCardBndrs"
+
+p_patSynSig ::
+  [Located RdrName] ->
+  HsImplicitBndrs GhcPs (LHsType GhcPs) ->
+  R ()
+p_patSynSig names hsib = do
+  txt "pattern"
+  let body = p_typeSig False names HsWC {hswc_ext = NoExt, hswc_body = hsib}
+  if length names > 1
+    then breakpoint >> inci body
+    else space >> body
+
+p_classOpSig ::
+  -- | Whether this is a \"default\" signature
+  Bool ->
+  -- | Names (before @::@)
+  [Located RdrName] ->
+  -- | Type
+  HsImplicitBndrs GhcPs (LHsType GhcPs) ->
+  R ()
+p_classOpSig def names hsib = do
+  when def (txt "default" >> space)
+  p_typeSig True names HsWC {hswc_ext = NoExt, hswc_body = hsib}
+
+p_fixSig ::
+  FixitySig GhcPs ->
+  R ()
+p_fixSig = \case
+  FixitySig NoExt names (Fixity _ n dir) -> do
+    txt $ case dir of
+      InfixL -> "infixl"
+      InfixR -> "infixr"
+      InfixN -> "infix"
+    space
+    atom n
+    space
+    sitcc $ sep (comma >> breakpoint) p_rdrName names
+  XFixitySig NoExt -> notImplemented "XFixitySig"
+
+p_inlineSig ::
+  -- | Name
+  Located RdrName ->
+  -- | Inline pragma specification
+  InlinePragma ->
+  R ()
+p_inlineSig name InlinePragma {..} = pragmaBraces $ do
+  p_inlineSpec inl_inline
+  space
+  case inl_rule of
+    ConLike -> txt "CONLIKE"
+    FunLike -> return ()
+  space
+  p_activation inl_act
+  space
+  p_rdrName name
+
+p_specSig ::
+  -- | Name
+  Located RdrName ->
+  -- | The types to specialize to
+  [LHsSigType GhcPs] ->
+  -- | For specialize inline
+  InlinePragma ->
+  R ()
+p_specSig name ts InlinePragma {..} = pragmaBraces $ do
+  txt "SPECIALIZE"
+  space
+  p_inlineSpec inl_inline
+  space
+  p_activation inl_act
+  space
+  p_rdrName name
+  space
+  txt "::"
+  breakpoint
+  inci $ sep (comma >> breakpoint) (located' p_hsType . hsib_body) ts
+
+p_inlineSpec :: InlineSpec -> R ()
+p_inlineSpec = \case
+  Inline -> txt "INLINE"
+  Inlinable -> txt "INLINEABLE"
+  NoInline -> txt "NOINLINE"
+  NoUserInline -> return ()
+
+p_activation :: Activation -> R ()
+p_activation = \case
+  NeverActive -> return ()
+  AlwaysActive -> return ()
+  ActiveBefore _ n -> do
+    txt "[~"
+    atom n
+    txt "]"
+  ActiveAfter _ n -> do
+    txt "["
+    atom n
+    txt "]"
+
+p_specInstSig :: LHsSigType GhcPs -> R ()
+p_specInstSig hsib =
+  pragma "SPECIALIZE instance" . inci $
+    located (hsib_body hsib) p_hsType
+
+p_minimalSig ::
+  -- | Boolean formula
+  LBooleanFormula (Located RdrName) ->
+  R ()
+p_minimalSig =
+  located' $ \booleanFormula ->
+    pragma "MINIMAL" (inci $ p_booleanFormula booleanFormula)
+
+p_booleanFormula ::
+  -- | Boolean formula
+  BooleanFormula (Located RdrName) ->
+  R ()
+p_booleanFormula = \case
+  Var name -> p_rdrName name
+  And xs ->
+    sitcc $
+      sep
+        (comma >> breakpoint)
+        (located' p_booleanFormula)
+        xs
+  Or xs ->
+    sitcc $
+      sep
+        (breakpoint >> txt "| ")
+        (located' p_booleanFormula)
+        xs
+  Parens l -> located l (parens N . p_booleanFormula)
+
+p_completeSig ::
+  -- | Constructors\/patterns
+  Located [Located RdrName] ->
+  -- | Type
+  Maybe (Located RdrName) ->
+  R ()
+p_completeSig cs' mty =
+  located cs' $ \cs ->
+    pragma "COMPLETE" . inci $ do
+      sitcc $ sep (comma >> breakpoint) p_rdrName cs
+      forM_ mty $ \ty -> do
+        space
+        txt "::"
+        breakpoint
+        inci (p_rdrName ty)
+
+p_sccSig :: Located (IdP GhcPs) -> Maybe (Located StringLiteral) -> R ()
+p_sccSig loc literal = pragma "SCC" . inci $ do
+  p_rdrName loc
+  forM_ literal $ \x -> do
+    breakpoint
+    atom x
diff --git a/src/Ormolu/Printer/Meat/Declaration/Splice.hs b/src/Ormolu/Printer/Meat/Declaration/Splice.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Splice.hs
@@ -0,0 +1,16 @@
+{-# LANGUAGE LambdaCase #-}
+
+module Ormolu.Printer.Meat.Declaration.Splice
+  ( p_spliceDecl,
+  )
+where
+
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Declaration.Value (p_hsSplice)
+import Ormolu.Utils
+
+p_spliceDecl :: SpliceDecl GhcPs -> R ()
+p_spliceDecl = \case
+  SpliceDecl NoExt splice _explicit -> located splice p_hsSplice
+  XSpliceDecl {} -> notImplemented "XSpliceDecl"
diff --git a/src/Ormolu/Printer/Meat/Declaration/Type.hs b/src/Ormolu/Printer/Meat/Declaration/Type.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Type.hs
@@ -0,0 +1,40 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Rendering of type synonym declarations.
+module Ormolu.Printer.Meat.Declaration.Type
+  ( p_synDecl,
+  )
+where
+
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import Ormolu.Printer.Meat.Type
+import RdrName (RdrName (..))
+import SrcLoc (Located)
+
+p_synDecl ::
+  -- | Type constructor
+  Located RdrName ->
+  -- | Fixity
+  LexicalFixity ->
+  -- | Type variables
+  LHsQTyVars GhcPs ->
+  -- | RHS of type declaration
+  LHsType GhcPs ->
+  R ()
+p_synDecl name fixity tvars t = do
+  txt "type"
+  space
+  let HsQTvs {..} = tvars
+  switchLayout (getLoc name : map getLoc hsq_explicit) $ do
+    p_infixDefHelper
+      (case fixity of Infix -> True; _ -> False)
+      inci
+      (p_rdrName name)
+      (map (located' p_hsTyVarBndr) hsq_explicit)
+  space
+  txt "="
+  breakpoint
+  inci (located t p_hsType)
diff --git a/src/Ormolu/Printer/Meat/Declaration/TypeFamily.hs b/src/Ormolu/Printer/Meat/Declaration/TypeFamily.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/TypeFamily.hs
@@ -0,0 +1,111 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Rendering of data\/type families.
+module Ormolu.Printer.Meat.Declaration.TypeFamily
+  ( p_famDecl,
+    p_tyFamInstEqn,
+  )
+where
+
+import BasicTypes (LexicalFixity (..))
+import Control.Monad
+import Data.Maybe (isJust, isNothing)
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import Ormolu.Printer.Meat.Type
+import Ormolu.Utils
+import SrcLoc (GenLocated (..), Located)
+
+p_famDecl :: FamilyStyle -> FamilyDecl GhcPs -> R ()
+p_famDecl style FamilyDecl {..} = do
+  mmeqs <- case fdInfo of
+    DataFamily -> Nothing <$ txt "data"
+    OpenTypeFamily -> Nothing <$ txt "type"
+    ClosedTypeFamily eqs -> Just eqs <$ txt "type"
+  txt $ case style of
+    Associated -> mempty
+    Free -> " family"
+  let HsQTvs {..} = fdTyVars
+  breakpoint
+  inci $ do
+    switchLayout (getLoc fdLName : (getLoc <$> hsq_explicit)) $ do
+      p_infixDefHelper
+        (isInfix fdFixity)
+        inci
+        (p_rdrName fdLName)
+        (located' p_hsTyVarBndr <$> hsq_explicit)
+    let rsig = p_familyResultSigL (isJust fdInjectivityAnn) fdResultSig
+    unless (isNothing rsig && isNothing fdInjectivityAnn) $
+      space
+    inci $ do
+      sequence_ rsig
+      when (isJust rsig && isJust fdInjectivityAnn) breakpoint
+      forM_ fdInjectivityAnn (located' p_injectivityAnn)
+  case mmeqs of
+    Nothing -> return ()
+    Just meqs -> do
+      space
+      txt "where"
+      case meqs of
+        Nothing -> do
+          space
+          txt ".."
+        Just eqs -> do
+          newline
+          sep newline (located' (inci . p_tyFamInstEqn)) eqs
+p_famDecl _ (XFamilyDecl NoExt) = notImplemented "XFamilyDecl"
+
+p_familyResultSigL ::
+  Bool ->
+  Located (FamilyResultSig GhcPs) ->
+  Maybe (R ())
+p_familyResultSigL injAnn l =
+  case l of
+    L _ a -> case a of
+      NoSig NoExt -> Nothing
+      KindSig NoExt k -> Just $ do
+        if injAnn then txt "=" else txt "::"
+        breakpoint
+        located k p_hsType
+      TyVarSig NoExt bndr -> Just $ do
+        if injAnn then txt "=" else txt "::"
+        breakpoint
+        located bndr p_hsTyVarBndr
+      XFamilyResultSig NoExt ->
+        notImplemented "XFamilyResultSig"
+
+p_injectivityAnn :: InjectivityAnn GhcPs -> R ()
+p_injectivityAnn (InjectivityAnn a bs) = do
+  txt "|"
+  space
+  p_rdrName a
+  space
+  txt "->"
+  space
+  sep space p_rdrName bs
+
+p_tyFamInstEqn :: TyFamInstEqn GhcPs -> R ()
+p_tyFamInstEqn HsIB {..} = do
+  let FamEqn {..} = hsib_body
+  switchLayout (getLoc feqn_tycon : (getLoc <$> feqn_pats)) $
+    p_infixDefHelper
+      (isInfix feqn_fixity)
+      inci
+      (p_rdrName feqn_tycon)
+      (located' p_hsType <$> feqn_pats)
+  space
+  txt "="
+  breakpoint
+  inci (located feqn_rhs p_hsType)
+p_tyFamInstEqn (XHsImplicitBndrs NoExt) = notImplemented "XHsImplicitBndrs"
+
+----------------------------------------------------------------------------
+-- Helpers
+
+isInfix :: LexicalFixity -> Bool
+isInfix = \case
+  Infix -> True
+  Prefix -> False
diff --git a/src/Ormolu/Printer/Meat/Declaration/Value.hs b/src/Ormolu/Printer/Meat/Declaration/Value.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Value.hs
@@ -0,0 +1,1273 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+module Ormolu.Printer.Meat.Declaration.Value
+  ( p_valDecl,
+    p_pat,
+    p_hsExpr,
+    p_hsSplice,
+    p_stringLit,
+  )
+where
+
+import Bag (bagToList)
+import BasicTypes
+import Control.Monad
+import Ctype (is_space)
+import Data.Bool (bool)
+import Data.Char (isPunctuation, isSymbol)
+import Data.Data hiding (Infix, Prefix)
+import Data.List (intersperse, sortOn)
+import Data.List.NonEmpty ((<|), NonEmpty ((:|)))
+import qualified Data.List.NonEmpty as NE
+import Data.Text (Text)
+import qualified Data.Text as Text
+import GHC
+import OccName (mkVarOcc)
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import {-# SOURCE #-} Ormolu.Printer.Meat.Declaration
+import Ormolu.Printer.Meat.Declaration.Signature
+import Ormolu.Printer.Meat.Type
+import Ormolu.Printer.Operators
+import Ormolu.Utils
+import RdrName (RdrName (..))
+import RdrName (rdrNameOcc)
+import SrcLoc (combineSrcSpans, isOneLineSpan)
+
+-- | Style of a group of equations.
+data MatchGroupStyle
+  = Function (Located RdrName)
+  | PatternBind
+  | Case
+  | Lambda
+  | LambdaCase
+
+-- | Style of equations in a group.
+data GroupStyle
+  = EqualSign
+  | RightArrow
+
+-- | Expression placement. This marks the places where expressions that
+-- implement handing forms may use them.
+data Placement
+  = -- | Multi-line layout should cause
+    -- insertion of a newline and indentation
+    -- bump
+    Normal
+  | -- | Expressions that have hanging form
+    -- should use it and avoid bumping one level
+    -- of indentation
+    Hanging
+  deriving (Eq)
+
+p_valDecl :: HsBindLR GhcPs GhcPs -> R ()
+p_valDecl = \case
+  FunBind NoExt funId funMatches _ _ -> p_funBind funId funMatches
+  PatBind NoExt pat grhss _ -> p_match PatternBind False NoSrcStrict [pat] grhss
+  VarBind {} -> notImplemented "VarBinds" -- introduced by the type checker
+  AbsBinds {} -> notImplemented "AbsBinds" -- introduced by the type checker
+  PatSynBind NoExt psb -> p_patSynBind psb
+  XHsBindsLR NoExt -> notImplemented "XHsBindsLR"
+
+p_funBind ::
+  Located RdrName ->
+  MatchGroup GhcPs (LHsExpr GhcPs) ->
+  R ()
+p_funBind name = p_matchGroup (Function name)
+
+p_matchGroup ::
+  MatchGroupStyle ->
+  MatchGroup GhcPs (LHsExpr GhcPs) ->
+  R ()
+p_matchGroup = p_matchGroup' exprPlacement p_hsExpr
+
+p_matchGroup' ::
+  Data body =>
+  -- | How to get body placement
+  (body -> Placement) ->
+  -- | How to print body
+  (body -> R ()) ->
+  -- | Style of this group of equations
+  MatchGroupStyle ->
+  -- | Match group
+  MatchGroup GhcPs (Located body) ->
+  R ()
+p_matchGroup' placer render style MG {..} = do
+  let ob = case style of
+        Case -> id
+        LambdaCase -> id
+        _ -> dontUseBraces
+  -- NOTE since we are forcing braces on 'sepSemi' based on 'ob', we have to
+  -- restore the brace state inside the sepsemi.
+  ub <- bool dontUseBraces useBraces <$> canUseBraces
+  ob $ sepSemi (located' (ub . p_Match)) (unLoc mg_alts)
+  where
+    p_Match m@Match {..} =
+      p_match'
+        placer
+        render
+        (adjustMatchGroupStyle m style)
+        (isInfixMatch m)
+        (matchStrictness m)
+        m_pats
+        m_grhss
+    p_Match _ = notImplemented "XMatch"
+p_matchGroup' _ _ _ (XMatchGroup NoExt) = notImplemented "XMatchGroup"
+
+-- | Function id obtained through pattern matching on 'FunBind' should not
+-- be used to print the actual equations because the different ‘RdrNames’
+-- used in the equations may have different “decorations” (such as backticks
+-- and paretheses) associated with them. It is necessary to use per-equation
+-- names obtained from 'm_ctxt' of 'Match'. This function replaces function
+-- name inside of 'Function' accordingly.
+adjustMatchGroupStyle ::
+  Match GhcPs body ->
+  MatchGroupStyle ->
+  MatchGroupStyle
+adjustMatchGroupStyle m = \case
+  Function _ -> (Function . mc_fun . m_ctxt) m
+  style -> style
+
+matchStrictness :: Match id body -> SrcStrictness
+matchStrictness match =
+  case m_ctxt match of
+    FunRhs {mc_strictness = s} -> s
+    _ -> NoSrcStrict
+
+p_match ::
+  -- | Style of the group
+  MatchGroupStyle ->
+  -- | Is this an infix match?
+  Bool ->
+  -- | Strictness prefix (FunBind)
+  SrcStrictness ->
+  -- | Argument patterns
+  [LPat GhcPs] ->
+  -- | Equations
+  GRHSs GhcPs (LHsExpr GhcPs) ->
+  R ()
+p_match = p_match' exprPlacement p_hsExpr
+
+p_match' ::
+  Data body =>
+  -- | How to get body placement
+  (body -> Placement) ->
+  -- | How to print body
+  (body -> R ()) ->
+  -- | Style of this group of equations
+  MatchGroupStyle ->
+  -- | Is this an infix match?
+  Bool ->
+  -- | Strictness prefix (FunBind)
+  SrcStrictness ->
+  -- | Argument patterns
+  [LPat GhcPs] ->
+  -- | Equations
+  GRHSs GhcPs (Located body) ->
+  R ()
+p_match' placer render style isInfix strictness m_pats m_grhss = do
+  -- NOTE Normally, since patterns may be placed in a multi-line layout, it
+  -- is necessary to bump indentation for the pattern group so it's more
+  -- indented than function name. This in turn means that indentation for
+  -- the body should also be bumped. Normally this would mean that bodies
+  -- would start with two indentation steps applied, which is ugly, so we
+  -- need to be a bit more clever here and bump indentation level only when
+  -- pattern group is multiline.
+  case strictness of
+    NoSrcStrict -> return ()
+    SrcStrict -> txt "!"
+    SrcLazy -> txt "~"
+  inci' <- case NE.nonEmpty m_pats of
+    Nothing -> id <$ case style of
+      Function name -> p_rdrName name
+      _ -> return ()
+    Just ne_pats -> do
+      let combinedSpans =
+            combineSrcSpans' $
+              getLoc <$> ne_pats
+          inci' =
+            if isOneLineSpan combinedSpans
+              then id
+              else inci
+      switchLayout [combinedSpans] $ do
+        let stdCase = sep breakpoint (located' p_pat) m_pats
+        case style of
+          Function name ->
+            p_infixDefHelper
+              isInfix
+              inci'
+              (p_rdrName name)
+              (located' p_pat <$> m_pats)
+          PatternBind -> stdCase
+          Case -> stdCase
+          Lambda -> do
+            let needsSpace = case unLoc (NE.head ne_pats) of
+                  LazyPat _ _ -> True
+                  BangPat _ _ -> True
+                  SplicePat _ _ -> True
+                  _ -> False
+            txt "\\"
+            when needsSpace space
+            sitcc stdCase
+          LambdaCase -> stdCase
+      return inci'
+  let -- Calculate position of end of patterns. This is useful when we decide
+      -- about putting certain constructions in hanging positions.
+      endOfPats = case NE.nonEmpty m_pats of
+        Nothing -> case style of
+          Function name -> (Just . srcSpanEnd . getLoc) name
+          _ -> Nothing
+        Just pats -> (Just . srcSpanEnd . getLoc . NE.last) pats
+      isCase = \case
+        Case -> True
+        LambdaCase -> True
+        _ -> False
+  let GRHSs {..} = m_grhss
+      hasGuards = withGuards grhssGRHSs
+  unless (length grhssGRHSs > 1) $ do
+    case style of
+      Function _ | hasGuards -> return ()
+      Function _ -> space >> txt "="
+      PatternBind -> space >> txt "="
+      s | isCase s && hasGuards -> return ()
+      _ -> space >> txt "->"
+  let grhssSpan =
+        combineSrcSpans' $
+          getGRHSSpan . unLoc <$> NE.fromList grhssGRHSs
+      patGrhssSpan =
+        maybe
+          grhssSpan
+          (combineSrcSpans grhssSpan . srcLocSpan)
+          endOfPats
+      placement =
+        case endOfPats of
+          Nothing -> blockPlacement placer grhssGRHSs
+          Just spn ->
+            if isOneLineSpan
+              (mkSrcSpan spn (srcSpanStart grhssSpan))
+              then blockPlacement placer grhssGRHSs
+              else Normal
+      p_body = do
+        let groupStyle =
+              if isCase style && hasGuards
+                then RightArrow
+                else EqualSign
+        sep newline (located' (p_grhs' placer render groupStyle)) grhssGRHSs
+      p_where = do
+        let whereIsEmpty = GHC.isEmptyLocalBindsPR (unLoc grhssLocalBinds)
+        unless (GHC.eqEmptyLocalBinds (unLoc grhssLocalBinds)) $ do
+          breakpoint
+          txt "where"
+          unless whereIsEmpty breakpoint
+          inci $ located grhssLocalBinds p_hsLocalBinds
+  inci' $ do
+    switchLayout [patGrhssSpan] $
+      placeHanging placement p_body
+    inci p_where
+
+p_grhs :: GroupStyle -> GRHS GhcPs (LHsExpr GhcPs) -> R ()
+p_grhs = p_grhs' exprPlacement p_hsExpr
+
+p_grhs' ::
+  Data body =>
+  -- | How to get body placement
+  (body -> Placement) ->
+  -- | How to print body
+  (body -> R ()) ->
+  GroupStyle ->
+  GRHS GhcPs (Located body) ->
+  R ()
+p_grhs' placer render style (GRHS NoExt guards body) =
+  case guards of
+    [] -> p_body
+    xs -> do
+      txt "|"
+      space
+      sitcc (sep (comma >> breakpoint) (sitcc . located' p_stmt) xs)
+      space
+      txt $ case style of
+        EqualSign -> "="
+        RightArrow -> "->"
+      placeHanging placement p_body
+  where
+    placement =
+      case endOfGuards of
+        Nothing -> placer (unLoc body)
+        Just spn ->
+          if isOneLineSpan (mkSrcSpan spn (srcSpanStart (getLoc body)))
+            then placer (unLoc body)
+            else Normal
+    endOfGuards =
+      case NE.nonEmpty guards of
+        Nothing -> Nothing
+        Just gs -> (Just . srcSpanEnd . getLoc . NE.last) gs
+    p_body = located body render
+p_grhs' _ _ _ (XGRHS NoExt) = notImplemented "XGRHS"
+
+p_hsCmd :: HsCmd GhcPs -> R ()
+p_hsCmd = \case
+  HsCmdArrApp NoExt body input arrType _ -> do
+    located body p_hsExpr
+    space
+    case arrType of
+      HsFirstOrderApp -> txt "-<"
+      HsHigherOrderApp -> txt "-<<"
+    placeHanging (exprPlacement (unLoc input)) $
+      located input p_hsExpr
+  HsCmdArrForm NoExt form Prefix _ cmds -> banana $ sitcc $ do
+    located form p_hsExpr
+    unless (null cmds) $ do
+      breakpoint
+      inci (sequence_ (intersperse breakpoint (located' p_hsCmdTop <$> cmds)))
+  HsCmdArrForm NoExt form Infix _ [left, right] -> do
+    located left p_hsCmdTop
+    space
+    located form p_hsExpr
+    placeHanging (cmdTopPlacement (unLoc right)) $
+      located right p_hsCmdTop
+  HsCmdArrForm NoExt _ Infix _ _ -> notImplemented "HsCmdArrForm"
+  HsCmdApp {} ->
+    -- XXX Does this ever occur in the syntax tree? It does not seem like it
+    -- does. Open an issue and ping @yumiova if this ever occurs in output.
+    notImplemented "HsCmdApp"
+  HsCmdLam NoExt mgroup -> p_matchGroup' cmdPlacement p_hsCmd Lambda mgroup
+  HsCmdPar NoExt c -> parens N (located c p_hsCmd)
+  HsCmdCase NoExt e mgroup ->
+    p_case cmdPlacement p_hsCmd e mgroup
+  HsCmdIf NoExt _ if' then' else' ->
+    p_if cmdPlacement p_hsCmd if' then' else'
+  HsCmdLet NoExt localBinds c ->
+    p_let p_hsCmd localBinds c
+  HsCmdDo NoExt es -> do
+    txt "do"
+    newline
+    inci . located es $
+      sitcc . sep newline (located' (sitcc . p_stmt' cmdPlacement p_hsCmd))
+  HsCmdWrap {} -> notImplemented "HsCmdWrap"
+  XCmd {} -> notImplemented "XCmd"
+
+p_hsCmdTop :: HsCmdTop GhcPs -> R ()
+p_hsCmdTop = \case
+  HsCmdTop NoExt cmd -> located cmd p_hsCmd
+  XCmdTop {} -> notImplemented "XHsCmdTop"
+
+p_stmt :: Stmt GhcPs (LHsExpr GhcPs) -> R ()
+p_stmt = p_stmt' exprPlacement p_hsExpr
+
+p_stmt' ::
+  Data body =>
+  -- | Placer
+  (body -> Placement) ->
+  -- | Render
+  (body -> R ()) ->
+  -- | Statement to render
+  Stmt GhcPs (Located body) ->
+  R ()
+p_stmt' placer render = \case
+  LastStmt NoExt body _ _ -> located body render
+  BindStmt NoExt l f _ _ -> do
+    located l p_pat
+    space
+    txt "<-"
+    let placement =
+          case f of
+            L l' x ->
+              if isOneLineSpan
+                (mkSrcSpan (srcSpanEnd (getLoc l)) (srcSpanStart l'))
+                then placer x
+                else Normal
+    switchLayout [getLoc l, getLoc f] $
+      placeHanging placement (located f render)
+  ApplicativeStmt {} -> notImplemented "ApplicativeStmt" -- generated by renamer
+  BodyStmt NoExt body _ _ -> located body render
+  LetStmt NoExt binds -> do
+    txt "let"
+    space
+    sitcc $ located binds p_hsLocalBinds
+  ParStmt {} ->
+    -- NOTE 'ParStmt' should always be eliminated in 'gatherStmt' already,
+    -- such that it never occurs in 'p_stmt''. Consequently, handling it
+    -- here would be redundant.
+    notImplemented "ParStmt"
+  TransStmt {..} -> do
+    -- NOTE 'TransStmt' only needs to account for render printing itself,
+    -- since pretty printing of relevant statements (e.g., in 'trS_stmts')
+    -- is handled through 'gatherStmt'.
+    case (trS_form, trS_by) of
+      (ThenForm, Nothing) -> do
+        txt "then"
+        breakpoint
+        inci $ located trS_using p_hsExpr
+      (ThenForm, Just e) -> do
+        txt "then"
+        breakpoint
+        inci $ located trS_using p_hsExpr
+        breakpoint
+        txt "by"
+        breakpoint
+        inci $ located e p_hsExpr
+      (GroupForm, Nothing) -> do
+        txt "then group using"
+        breakpoint
+        inci $ located trS_using p_hsExpr
+      (GroupForm, Just e) -> do
+        txt "then group by"
+        breakpoint
+        inci $ located e p_hsExpr
+        breakpoint
+        txt "using"
+        breakpoint
+        inci $ located trS_using p_hsExpr
+  RecStmt {..} -> do
+    txt "rec"
+    space
+    sitcc $ sepSemi (located' (p_stmt' placer render)) recS_stmts
+  XStmtLR {} -> notImplemented "XStmtLR"
+
+gatherStmt :: ExprLStmt GhcPs -> [[ExprLStmt GhcPs]]
+gatherStmt (L _ (ParStmt NoExt block _ _)) =
+  foldr ((<>) . gatherStmtBlock) [] block
+gatherStmt (L s stmt@TransStmt {..}) =
+  foldr liftAppend [] ((gatherStmt <$> trS_stmts) <> pure [[L s stmt]])
+gatherStmt stmt = [[stmt]]
+
+gatherStmtBlock :: ParStmtBlock GhcPs GhcPs -> [[ExprLStmt GhcPs]]
+gatherStmtBlock (ParStmtBlock _ stmts _ _) =
+  foldr (liftAppend . gatherStmt) [] stmts
+gatherStmtBlock XParStmtBlock {} = notImplemented "XParStmtBlock"
+
+p_hsLocalBinds :: HsLocalBindsLR GhcPs GhcPs -> R ()
+p_hsLocalBinds = \case
+  HsValBinds NoExt (ValBinds NoExt bag lsigs) -> do
+    let ssStart =
+          either
+            (srcSpanStart . getLoc)
+            (srcSpanStart . getLoc)
+        items =
+          (Left <$> bagToList bag) ++ (Right <$> lsigs)
+        p_item (Left x) = located x p_valDecl
+        p_item (Right x) = located x p_sigDecl
+        -- Assigns 'False' to the last element, 'True' to the rest.
+        markInit :: [a] -> [(Bool, a)]
+        markInit [] = []
+        markInit (x : []) = [(False, x)]
+        markInit (x : xs) = (True, x) : markInit xs
+    -- NOTE When in a single-line layout, there is a chance that the inner
+    -- elements will also contain semicolons and they will confuse the
+    -- parser. so we request braces around every element except the last.
+    br <- layoutToBraces <$> getLayout
+    sitcc $
+      sepSemi
+        (\(m, i) -> (if m then br else id) $ p_item i)
+        (markInit $ sortOn ssStart items)
+  HsValBinds NoExt _ -> notImplemented "HsValBinds"
+  HsIPBinds NoExt (IPBinds NoExt xs) ->
+    -- Second argument of IPBind is always Left before type-checking.
+    let p_ipBind (IPBind NoExt (Left name) expr) = do
+          atom name
+          space
+          txt "="
+          breakpoint
+          useBraces $ inci $ located expr p_hsExpr
+        p_ipBind _ = notImplemented "XHsIPBinds"
+     in sepSemi (located' p_ipBind) xs
+  HsIPBinds NoExt _ -> notImplemented "HsIpBinds"
+  EmptyLocalBinds NoExt -> return ()
+  XHsLocalBindsLR _ -> notImplemented "XHsLocalBindsLR"
+
+p_hsRecField ::
+  HsRecField' RdrName (LHsExpr GhcPs) ->
+  R ()
+p_hsRecField = \HsRecField {..} -> do
+  p_rdrName hsRecFieldLbl
+  unless hsRecPun $ do
+    space
+    txt "="
+    let placement = exprPlacement (unLoc hsRecFieldArg)
+    placeHanging placement $ located hsRecFieldArg p_hsExpr
+
+p_hsTupArg :: HsTupArg GhcPs -> R ()
+p_hsTupArg = \case
+  Present NoExt x -> located x p_hsExpr
+  Missing NoExt -> pure ()
+  XTupArg {} -> notImplemented "XTupArg"
+
+p_hsExpr :: HsExpr GhcPs -> R ()
+p_hsExpr = p_hsExpr' N
+
+p_hsExpr' :: BracketStyle -> HsExpr GhcPs -> R ()
+p_hsExpr' s = \case
+  HsVar NoExt name -> p_rdrName name
+  HsUnboundVar NoExt _ -> notImplemented "HsUnboundVar"
+  HsConLikeOut NoExt _ -> notImplemented "HsConLikeOut"
+  HsRecFld NoExt x ->
+    case x of
+      Unambiguous NoExt name -> p_rdrName name
+      Ambiguous NoExt name -> p_rdrName name
+      XAmbiguousFieldOcc NoExt -> notImplemented "XAmbiguousFieldOcc"
+  HsOverLabel NoExt _ v -> do
+    txt "#"
+    atom v
+  HsIPVar NoExt (HsIPName name) -> do
+    txt "?"
+    atom name
+  HsOverLit NoExt v -> atom (ol_val v)
+  HsLit NoExt lit ->
+    case lit of
+      HsString (SourceText stxt) _ -> p_stringLit stxt
+      HsStringPrim (SourceText stxt) _ -> p_stringLit stxt
+      r -> atom r
+  HsLam NoExt mgroup ->
+    p_matchGroup Lambda mgroup
+  HsLamCase NoExt mgroup -> do
+    txt "\\case"
+    breakpoint
+    inci (p_matchGroup LambdaCase mgroup)
+  HsApp NoExt f x -> do
+    let -- In order to format function applications with multiple parameters
+        -- nicer, traverse the AST to gather the function and all the
+        -- parameters together.
+        gatherArgs f' knownArgs =
+          case f' of
+            L _ (HsApp _ l r) -> gatherArgs l (r <| knownArgs)
+            _ -> (f', knownArgs)
+        (func, args) = gatherArgs f (x :| [])
+        -- We need to handle the last argument specially if it is a
+        -- hanging construct, so separate it from the rest.
+        (initp, lastp) = (NE.init args, NE.last args)
+        initSpan = combineSrcSpans' $ getLoc f :| map getLoc initp
+        -- Hang the last argument only if the initial arguments spans one
+        -- line.
+        placement =
+          if isOneLineSpan initSpan
+            then exprPlacement (unLoc lastp)
+            else Normal
+    -- If the last argument is not hanging, just separate every argument as
+    -- usual. If it is hanging, print the initial arguments and hang the
+    -- last one. Also, use braces around the every argument except the last
+    -- one.
+    case placement of
+      Normal -> do
+        useBraces $ do
+          located func (p_hsExpr' s)
+          breakpoint
+          inci $ sep breakpoint (located' p_hsExpr) initp
+        inci $ do
+          unless (null initp) breakpoint
+          located lastp p_hsExpr
+      Hanging -> do
+        useBraces . switchLayout [initSpan] $ do
+          located func (p_hsExpr' s)
+          breakpoint
+          sep breakpoint (located' p_hsExpr) initp
+        placeHanging placement $
+          located lastp p_hsExpr
+  HsAppType a e -> do
+    located e p_hsExpr
+    breakpoint
+    inci $ do
+      txt "@"
+      located (hswc_body a) p_hsType
+  OpApp NoExt x op y -> do
+    let opTree = OpBranch (exprOpTree x) op (exprOpTree y)
+    p_exprOpTree True s (reassociateOpTree getOpName opTree)
+  NegApp NoExt e _ -> do
+    txt "-"
+    space
+    located e p_hsExpr
+  HsPar NoExt e ->
+    parens s (located e (dontUseBraces . p_hsExpr))
+  SectionL NoExt x op -> do
+    located x p_hsExpr
+    breakpoint
+    inci (located op p_hsExpr)
+  SectionR NoExt op x -> do
+    located op p_hsExpr
+    breakpoint
+    inci (located x p_hsExpr)
+  ExplicitTuple NoExt args boxity -> do
+    let isSection = any (isMissing . unLoc) args
+        isMissing = \case
+          Missing NoExt -> True
+          _ -> False
+    let parens' =
+          case boxity of
+            Boxed -> parens
+            Unboxed -> parensHash
+    if isSection
+      then
+        switchLayout [] . parens' s $
+          sep comma (located' p_hsTupArg) args
+      else
+        switchLayout (getLoc <$> args) . parens' s . sitcc $
+          sep (comma >> breakpoint) (sitcc . located' p_hsTupArg) args
+  ExplicitSum NoExt tag arity e ->
+    p_unboxedSum N tag arity (located e p_hsExpr)
+  HsCase NoExt e mgroup ->
+    p_case exprPlacement p_hsExpr e mgroup
+  HsIf NoExt _ if' then' else' ->
+    p_if exprPlacement p_hsExpr if' then' else'
+  HsMultiIf NoExt guards -> do
+    txt "if"
+    breakpoint
+    inci . sitcc $ sep newline (located' (p_grhs RightArrow)) guards
+  HsLet NoExt localBinds e ->
+    p_let p_hsExpr localBinds e
+  HsDo NoExt ctx es -> do
+    let doBody header = do
+          txt header
+          breakpoint
+          ub <- layoutToBraces <$> getLayout
+          inci $
+            sepSemi
+              (located' (ub . p_stmt' exprPlacement (p_hsExpr' S)))
+              (unLoc es)
+        compBody = brackets N $ located es $ \xs -> do
+          let p_parBody =
+                sep
+                  (breakpoint >> txt "| ")
+                  p_seqBody
+              p_seqBody =
+                sitcc
+                  . sep
+                    (comma >> breakpoint)
+                    (located' (sitcc . p_stmt))
+              stmts = init xs
+              yield = last xs
+              lists = foldr (liftAppend . gatherStmt) [] stmts
+          located yield p_stmt
+          breakpoint
+          txt "|"
+          space
+          p_parBody lists
+    case ctx of
+      DoExpr -> doBody "do"
+      MDoExpr -> doBody "mdo"
+      ListComp -> compBody
+      MonadComp -> notImplemented "MonadComp"
+      ArrowExpr -> notImplemented "ArrowExpr"
+      GhciStmtCtxt -> notImplemented "GhciStmtCtxt"
+      PatGuard _ -> notImplemented "PatGuard"
+      ParStmtCtxt _ -> notImplemented "ParStmtCtxt"
+      TransStmtCtxt _ -> notImplemented "TransStmtCtxt"
+  ExplicitList _ _ xs ->
+    brackets s . sitcc $
+      sep (comma >> breakpoint) (sitcc . located' p_hsExpr) xs
+  RecordCon {..} -> do
+    located rcon_con_name atom
+    breakpoint
+    let HsRecFields {..} = rcon_flds
+        updName f =
+          f
+            { hsRecFieldLbl = case unLoc $ hsRecFieldLbl f of
+                FieldOcc _ n -> n
+                XFieldOcc _ -> notImplemented "XFieldOcc"
+            }
+        fields = located' (p_hsRecField . updName) <$> rec_flds
+        dotdot =
+          case rec_dotdot of
+            Just {} -> [txt ".."]
+            Nothing -> []
+    inci . braces N . sitcc $
+      sep (comma >> breakpoint) sitcc (fields <> dotdot)
+  RecordUpd {..} -> do
+    located rupd_expr p_hsExpr
+    breakpoint
+    let updName f =
+          f
+            { hsRecFieldLbl = case unLoc $ hsRecFieldLbl f of
+                Ambiguous _ n -> n
+                Unambiguous _ n -> n
+                XAmbiguousFieldOcc _ -> notImplemented "XAmbiguousFieldOcc"
+            }
+    inci . braces N . sitcc $
+      sep
+        (comma >> breakpoint)
+        (sitcc . located' (p_hsRecField . updName))
+        rupd_flds
+  ExprWithTySig affix x -> sitcc $ do
+    located x p_hsExpr
+    space
+    txt "::"
+    breakpoint
+    inci $ do
+      let HsWC {..} = affix
+          HsIB {..} = hswc_body
+      located hsib_body p_hsType
+  ArithSeq NoExt _ x -> do
+    case x of
+      From from -> brackets s . sitcc $ do
+        located from p_hsExpr
+        breakpoint
+        txt ".."
+      FromThen from next -> brackets s . sitcc $ do
+        sitcc $ sep (comma >> breakpoint) (located' p_hsExpr) [from, next]
+        breakpoint
+        txt ".."
+      FromTo from to -> brackets s . sitcc $ do
+        located from p_hsExpr
+        breakpoint
+        txt ".."
+        space
+        located to p_hsExpr
+      FromThenTo from next to -> brackets s . sitcc $ do
+        sitcc $ sep (comma >> breakpoint) (located' p_hsExpr) [from, next]
+        breakpoint
+        txt ".."
+        space
+        located to p_hsExpr
+  HsSCC NoExt _ name x -> do
+    txt "{-# SCC "
+    atom name
+    txt " #-}"
+    breakpoint
+    located x p_hsExpr
+  HsCoreAnn NoExt _ value x -> do
+    txt "{-# CORE "
+    atom value
+    txt " #-}"
+    breakpoint
+    located x p_hsExpr
+  HsBracket NoExt x -> p_hsBracket x
+  HsRnBracketOut {} -> notImplemented "HsRnBracketOut"
+  HsTcBracketOut {} -> notImplemented "HsTcBracketOut"
+  HsSpliceE NoExt splice -> p_hsSplice splice
+  HsProc NoExt p e -> do
+    txt "proc"
+    located p $ \x -> do
+      breakpoint
+      inci (p_pat x)
+      breakpoint
+    txt "->"
+    placeHanging (cmdTopPlacement (unLoc e)) $
+      located e p_hsCmdTop
+  HsStatic _ e -> do
+    txt "static"
+    breakpoint
+    inci (located e p_hsExpr)
+  HsArrApp NoExt body input arrType cond ->
+    p_hsCmd (HsCmdArrApp NoExt body input arrType cond)
+  HsArrForm NoExt form mfixity cmds ->
+    p_hsCmd (HsCmdArrForm NoExt form Prefix mfixity cmds)
+  HsTick {} -> notImplemented "HsTick"
+  HsBinTick {} -> notImplemented "HsBinTick"
+  HsTickPragma {} -> notImplemented "HsTickPragma"
+  -- These four constructs should never appear in correct programs.
+  -- See: https://github.com/tweag/ormolu/issues/343
+  EWildPat NoExt -> txt "_"
+  EAsPat NoExt n p -> do
+    p_rdrName n
+    txt "@"
+    located p p_hsExpr
+  EViewPat NoExt p e -> do
+    located p p_hsExpr
+    space
+    txt "->"
+    breakpoint
+    inci (located e p_hsExpr)
+  ELazyPat NoExt p -> do
+    txt "~"
+    located p p_hsExpr
+  HsWrap {} -> notImplemented "HsWrap"
+  XExpr {} -> notImplemented "XExpr"
+
+p_patSynBind :: PatSynBind GhcPs GhcPs -> R ()
+p_patSynBind PSB {..} = do
+  let rhs = do
+        space
+        case psb_dir of
+          Unidirectional -> do
+            txt "<-"
+            breakpoint
+            located psb_def p_pat
+          ImplicitBidirectional -> do
+            txt "="
+            breakpoint
+            located psb_def p_pat
+          ExplicitBidirectional mgroup -> do
+            txt "<-"
+            breakpoint
+            located psb_def p_pat
+            newline
+            txt "where"
+            newline
+            inci (p_matchGroup (Function psb_id) mgroup)
+  txt "pattern"
+  case psb_args of
+    PrefixCon xs -> do
+      space
+      p_rdrName psb_id
+      inci $ do
+        switchLayout (getLoc <$> xs) $ do
+          unless (null xs) breakpoint
+          sitcc (sep breakpoint p_rdrName xs)
+        rhs
+    RecCon xs -> do
+      space
+      p_rdrName psb_id
+      inci $ do
+        switchLayout (getLoc . recordPatSynPatVar <$> xs) $ do
+          unless (null xs) breakpoint
+          braces N . sitcc $
+            sep (comma >> breakpoint) (p_rdrName . recordPatSynPatVar) xs
+        rhs
+    InfixCon l r -> do
+      switchLayout [getLoc l, getLoc r] $ do
+        space
+        p_rdrName l
+        breakpoint
+        inci $ do
+          p_rdrName psb_id
+          space
+          p_rdrName r
+      inci rhs
+p_patSynBind (XPatSynBind NoExt) = notImplemented "XPatSynBind"
+
+p_case ::
+  Data body =>
+  -- | Placer
+  (body -> Placement) ->
+  -- | Render
+  (body -> R ()) ->
+  -- | Expression
+  LHsExpr GhcPs ->
+  -- | Match group
+  (MatchGroup GhcPs (Located body)) ->
+  R ()
+p_case placer render e mgroup = do
+  txt "case"
+  space
+  located e p_hsExpr
+  space
+  txt "of"
+  breakpoint
+  inci (p_matchGroup' placer render Case mgroup)
+
+p_if ::
+  Data body =>
+  -- | Placer
+  (body -> Placement) ->
+  -- | Render
+  (body -> R ()) ->
+  -- | If
+  LHsExpr GhcPs ->
+  -- | Then
+  Located body ->
+  -- | Else
+  Located body ->
+  R ()
+p_if placer render if' then' else' = do
+  txt "if"
+  space
+  located if' p_hsExpr
+  breakpoint
+  inci $ do
+    txt "then"
+    located then' $ \x ->
+      placeHanging (placer x) (render x)
+    breakpoint
+    txt "else"
+    located else' $ \x ->
+      placeHanging (placer x) (render x)
+
+p_let ::
+  Data body =>
+  -- | Render
+  (body -> R ()) ->
+  Located (HsLocalBindsLR GhcPs GhcPs) ->
+  Located body ->
+  R ()
+p_let render localBinds e = sitcc $ do
+  txt "let"
+  space
+  dontUseBraces $ sitcc (located localBinds p_hsLocalBinds)
+  vlayout space (newline >> txt " ")
+  txt "in"
+  space
+  sitcc (located e render)
+
+p_pat :: Pat GhcPs -> R ()
+p_pat = \case
+  WildPat NoExt -> txt "_"
+  VarPat NoExt name -> p_rdrName name
+  LazyPat NoExt pat -> do
+    txt "~"
+    located pat p_pat
+  AsPat NoExt name pat -> do
+    p_rdrName name
+    txt "@"
+    located pat p_pat
+  ParPat NoExt pat ->
+    located pat (parens S . p_pat)
+  BangPat NoExt pat -> do
+    txt "!"
+    located pat p_pat
+  ListPat NoExt pats -> do
+    brackets S . sitcc $ sep (comma >> breakpoint) (located' p_pat) pats
+  TuplePat NoExt pats boxing -> do
+    let f =
+          case boxing of
+            Boxed -> parens S
+            Unboxed -> parensHash S
+    f . sitcc $ sep (comma >> breakpoint) (sitcc . located' p_pat) pats
+  SumPat NoExt pat tag arity ->
+    p_unboxedSum S tag arity (located pat p_pat)
+  ConPatIn pat details ->
+    case details of
+      PrefixCon xs -> sitcc $ do
+        p_rdrName pat
+        unless (null xs) $ do
+          breakpoint
+          inci . sitcc $ sep breakpoint (sitcc . located' p_pat) xs
+      RecCon (HsRecFields fields dotdot) -> do
+        p_rdrName pat
+        breakpoint
+        let f = \case
+              Nothing -> txt ".."
+              Just x -> located x p_pat_hsRecField
+        inci . braces N . sitcc . sep (comma >> breakpoint) f $
+          case dotdot of
+            Nothing -> Just <$> fields
+            Just n -> (Just <$> take n fields) ++ [Nothing]
+      InfixCon x y -> do
+        located x p_pat
+        space
+        p_rdrName pat
+        breakpoint
+        inci (located y p_pat)
+  ConPatOut {} -> notImplemented "ConPatOut" -- presumably created by renamer?
+  ViewPat NoExt expr pat -> sitcc $ do
+    located expr p_hsExpr
+    space
+    txt "->"
+    breakpoint
+    inci (located pat p_pat)
+  SplicePat NoExt splice -> p_hsSplice splice
+  LitPat NoExt p -> atom p
+  NPat NoExt v _ _ -> located v (atom . ol_val)
+  NPlusKPat NoExt n k _ _ _ -> sitcc $ do
+    p_rdrName n
+    breakpoint
+    inci $ do
+      txt "+"
+      space
+      located k (atom . ol_val)
+  SigPat hswc pat -> do
+    located pat p_pat
+    p_typeAscription hswc
+  CoPat {} -> notImplemented "CoPat" -- apparently created at some later stage
+  XPat NoExt -> notImplemented "XPat"
+
+p_pat_hsRecField :: HsRecField' (FieldOcc GhcPs) (LPat GhcPs) -> R ()
+p_pat_hsRecField HsRecField {..} = do
+  located hsRecFieldLbl $ \x ->
+    p_rdrName (rdrNameFieldOcc x)
+  unless hsRecPun $ do
+    space
+    txt "="
+    breakpoint
+    inci (located hsRecFieldArg p_pat)
+
+p_unboxedSum :: BracketStyle -> ConTag -> Arity -> R () -> R ()
+p_unboxedSum s tag arity m = do
+  let before = tag - 1
+      after = arity - before - 1
+      args = replicate before Nothing <> [Just m] <> replicate after Nothing
+      f (x, i) = do
+        let isFirst = i == 0
+            isLast = i == arity - 1
+        case x :: Maybe (R ()) of
+          Nothing ->
+            unless (isFirst || isLast) space
+          Just m' -> do
+            unless isFirst space
+            m'
+            unless isLast space
+  parensHash s $ sep (txt "|") f (zip args [0 ..])
+
+p_hsSplice :: HsSplice GhcPs -> R ()
+p_hsSplice = \case
+  HsTypedSplice NoExt deco _ expr -> p_hsSpliceTH True expr deco
+  HsUntypedSplice NoExt deco _ expr -> p_hsSpliceTH False expr deco
+  HsQuasiQuote NoExt _ quoterName srcSpan str -> do
+    txt "["
+    p_rdrName (L srcSpan quoterName)
+    txt "|"
+    -- NOTE QuasiQuoters often rely on precise custom strings. We cannot do
+    -- any formatting here without potentially breaking someone's code.
+    atom str
+    txt "|]"
+  HsSpliced {} -> notImplemented "HsSpliced"
+  XSplice {} -> notImplemented "XSplice"
+
+p_hsSpliceTH ::
+  -- | Typed splice?
+  Bool ->
+  -- | Splice expression
+  LHsExpr GhcPs ->
+  -- | Splice decoration
+  SpliceDecoration ->
+  R ()
+p_hsSpliceTH isTyped expr = \case
+  HasParens -> do
+    txt decoSymbol
+    parens N (located expr (sitcc . p_hsExpr))
+  HasDollar -> do
+    txt decoSymbol
+    located expr (sitcc . p_hsExpr)
+  NoParens ->
+    located expr (sitcc . p_hsExpr)
+  where
+    decoSymbol = if isTyped then "$$" else "$"
+
+p_hsBracket :: HsBracket GhcPs -> R ()
+p_hsBracket = \case
+  ExpBr NoExt expr -> do
+    anns <- getEnclosingAnns
+    let name = case anns of
+          AnnOpenEQ : _ -> ""
+          _ -> "e"
+    quote name (located expr p_hsExpr)
+  PatBr NoExt pat -> quote "p" (located pat p_pat)
+  DecBrL NoExt decls -> quote "d" (p_hsDecls Free decls)
+  DecBrG NoExt _ -> notImplemented "DecBrG" -- result of renamer
+  TypBr NoExt ty -> quote "t" (located ty p_hsType)
+  VarBr NoExt isSingleQuote name -> do
+    txt (bool "''" "'" isSingleQuote)
+    -- HACK As you can see we use 'noLoc' here to be able to pass name into
+    -- 'p_rdrName' since the latter expects a "located" thing. The problem
+    -- is that 'VarBr' doesn't provide us with location of the name. This in
+    -- turn makes it impossible to detect if there are parentheses around
+    -- it, etc. So we have to add parentheses manually assuming they are
+    -- necessary for all operators.
+    let isOperator =
+          all
+            (\i -> isPunctuation i || isSymbol i)
+            (showOutputable (rdrNameOcc name))
+            && not (doesNotNeedExtraParens name)
+        wrapper = if isOperator then parens N else id
+    wrapper $ p_rdrName (noLoc name)
+  TExpBr NoExt expr -> do
+    txt "[||"
+    breakpoint'
+    located expr p_hsExpr
+    breakpoint'
+    txt "||]"
+  XBracket {} -> notImplemented "XBracket"
+  where
+    quote :: Text -> R () -> R ()
+    quote name body = do
+      txt "["
+      txt name
+      txt "|"
+      breakpoint'
+      inci $ do
+        dontUseBraces body
+        breakpoint'
+        txt "|]"
+
+-- Print the source text of a string literal while indenting
+-- gaps correctly.
+
+p_stringLit :: String -> R ()
+p_stringLit src =
+  let s = splitGaps src
+      singleLine =
+        txt $ Text.pack (mconcat s)
+      multiLine =
+        sitcc $ sep breakpoint (txt . Text.pack) (backslashes s)
+   in vlayout singleLine multiLine
+  where
+    -- Split a string on gaps (backslash delimited whitespaces)
+    --
+    -- > splitGaps "bar\\  \\fo\\&o" == ["bar", "fo\\&o"]
+    splitGaps :: String -> [String]
+    splitGaps "" = []
+    splitGaps s =
+      let -- A backslash and a whitespace starts a "gap"
+          p (Just '\\', _, _) = True
+          p (_, '\\', Just c) | ghcSpace c = False
+          p _ = True
+       in case span p (zipPrevNext s) of
+            (l, r) ->
+              let -- drop the initial '\', any amount of 'ghcSpace', and another '\'
+                  r' = drop 1 . dropWhile ghcSpace . drop 1 $ map orig r
+               in map orig l : splitGaps r'
+    -- GHC's definition of whitespaces in strings
+    -- See: https://gitlab.haskell.org/ghc/ghc/blob/86753475/compiler/parser/Lexer.x#L1653
+    ghcSpace :: Char -> Bool
+    ghcSpace c = c <= '\x7f' && is_space c
+    -- Add backslashes to the inner side of the strings
+    --
+    -- > backslashes ["a", "b", "c"] == ["a\\", "\\b\\", "\\c"]
+    backslashes :: [String] -> [String]
+    backslashes (x : y : xs) = (x ++ "\\") : backslashes (('\\' : y) : xs)
+    backslashes xs = xs
+    -- Attaches previous and next items to each list element
+    zipPrevNext :: [a] -> [(Maybe a, a, Maybe a)]
+    zipPrevNext xs =
+      let z =
+            zip
+              (zip (Nothing : map Just xs) xs)
+              (map Just (tail xs) ++ repeat Nothing)
+       in map (\((p, x), n) -> (p, x, n)) z
+    orig (_, x, _) = x
+
+----------------------------------------------------------------------------
+-- Helpers
+
+-- | Return the wrapping function controlling the use of braces according to
+-- the current layout.
+layoutToBraces :: Layout -> R () -> R ()
+layoutToBraces = \case
+  SingleLine -> useBraces
+  MultiLine -> id
+
+-- | Append each element in both lists with semigroups. If one list is shorter
+-- than the other, return the rest of the longer list unchanged.
+liftAppend :: Semigroup a => [a] -> [a] -> [a]
+liftAppend [] [] = []
+liftAppend [] (y : ys) = y : ys
+liftAppend (x : xs) [] = x : xs
+liftAppend (x : xs) (y : ys) = x <> y : liftAppend xs ys
+
+getGRHSSpan :: GRHS GhcPs (Located body) -> SrcSpan
+getGRHSSpan (GRHS NoExt guards body) =
+  combineSrcSpans' $ getLoc body :| map getLoc guards
+getGRHSSpan (XGRHS NoExt) = notImplemented "XGRHS"
+
+-- | Place a thing that may have a hanging form. This function handles how
+-- to separate it from preceding expressions and whether to bump indentation
+-- depending on what sort of expression we have.
+placeHanging :: Placement -> R () -> R ()
+placeHanging placement m =
+  case placement of
+    Hanging -> do
+      space
+      m
+    Normal -> do
+      breakpoint
+      inci m
+
+-- | Check if given block contains single expression which has a hanging
+-- form.
+blockPlacement ::
+  (body -> Placement) ->
+  [LGRHS GhcPs (Located body)] ->
+  Placement
+blockPlacement placer [(L _ (GRHS NoExt _ (L _ x)))] = placer x
+blockPlacement _ _ = Normal
+
+-- | Check if given command has a hanging form.
+cmdPlacement :: HsCmd GhcPs -> Placement
+cmdPlacement = \case
+  HsCmdLam NoExt _ -> Hanging
+  HsCmdCase NoExt _ _ -> Hanging
+  HsCmdDo NoExt _ -> Hanging
+  _ -> Normal
+
+cmdTopPlacement :: HsCmdTop GhcPs -> Placement
+cmdTopPlacement = \case
+  HsCmdTop NoExt (L _ x) -> cmdPlacement x
+  XCmdTop {} -> notImplemented "XCmdTop"
+
+-- | Check if given expression has a hanging form.
+exprPlacement :: HsExpr GhcPs -> Placement
+exprPlacement = \case
+  -- Only hang lambdas with single line parameter lists
+  HsLam NoExt mg -> case mg of
+    MG _ (L _ [L _ (Match NoExt _ (x : xs) _)]) _
+      | isOneLineSpan (combineSrcSpans' $ fmap getLoc (x :| xs)) ->
+        Hanging
+    _ -> Normal
+  HsLamCase NoExt _ -> Hanging
+  HsCase NoExt _ _ -> Hanging
+  HsDo NoExt DoExpr _ -> Hanging
+  HsDo NoExt MDoExpr _ -> Hanging
+  RecordCon NoExt _ _ -> Hanging
+  -- If the rightmost expression in an operator chain is hanging, make the
+  -- whole block hanging; so that we can use the common @f = foo $ do@
+  -- style.
+  OpApp NoExt _ _ y -> exprPlacement (unLoc y)
+  -- Same thing for function applications (usually with -XBlockArguments)
+  HsApp NoExt _ y -> exprPlacement (unLoc y)
+  HsProc NoExt (L s _) _ ->
+    -- Indentation breaks if pattern is longer than one line and left
+    -- hanging. Consequently, only apply hanging when it is safe.
+    if isOneLineSpan s
+      then Hanging
+      else Normal
+  _ -> Normal
+
+withGuards :: [LGRHS GhcPs (Located body)] -> Bool
+withGuards = any (checkOne . unLoc)
+  where
+    checkOne :: GRHS GhcPs (Located body) -> Bool
+    checkOne (GRHS NoExt [] _) = False
+    checkOne _ = True
+
+exprOpTree :: LHsExpr GhcPs -> OpTree (LHsExpr GhcPs) (LHsExpr GhcPs)
+exprOpTree (L _ (OpApp NoExt x op y)) = OpBranch (exprOpTree x) op (exprOpTree y)
+exprOpTree n = OpNode n
+
+getOpName :: HsExpr GhcPs -> Maybe RdrName
+getOpName = \case
+  HsVar NoExt (L _ a) -> Just a
+  _ -> Nothing
+
+p_exprOpTree ::
+  -- | Can use special handling of dollar?
+  Bool ->
+  -- | Bracket style to use
+  BracketStyle ->
+  OpTree (LHsExpr GhcPs) (LHsExpr GhcPs) ->
+  R ()
+p_exprOpTree _ s (OpNode x) = located x (p_hsExpr' s)
+p_exprOpTree isDollarSpecial s (OpBranch x op y) = do
+  -- NOTE If the beginning of the first argument and the second argument
+  -- are on the same line, and the second argument has a hanging form, use
+  -- hanging placement.
+  let placement =
+        if isOneLineSpan
+          (mkSrcSpan (srcSpanStart (opTreeLoc x)) (srcSpanStart (opTreeLoc y)))
+          then case y of
+            OpNode (L _ n) -> exprPlacement n
+            _ -> Normal
+          else Normal
+      opWrapper = case unLoc op of
+        EWildPat NoExt -> backticks
+        _ -> id
+  layout <- getLayout
+  let ub = case layout of
+        SingleLine -> useBraces
+        MultiLine -> case placement of
+          Hanging -> useBraces
+          Normal -> dontUseBraces
+      gotDollar = case getOpName (unLoc op) of
+        Just rname -> mkVarOcc "$" == (rdrNameOcc rname)
+        _ -> False
+  switchLayout [opTreeLoc x]
+    $ ub
+    $ p_exprOpTree (not gotDollar) s x
+  let p_op = located op (opWrapper . p_hsExpr)
+      p_y = switchLayout [opTreeLoc y] (p_exprOpTree True N y)
+  if isDollarSpecial && gotDollar && placement == Normal && isOneLineSpan (opTreeLoc x)
+    then do
+      space
+      p_op
+      breakpoint
+      inci p_y
+    else placeHanging placement $ do
+      p_op
+      space
+      p_y
+
+-- | Get annotations for the enclosing element.
+getEnclosingAnns :: R [AnnKeywordId]
+getEnclosingAnns = do
+  e <- getEnclosingSpan (const True)
+  case e of
+    Nothing -> return []
+    Just e' -> getAnns (RealSrcSpan e')
diff --git a/src/Ormolu/Printer/Meat/Declaration/Value.hs-boot b/src/Ormolu/Printer/Meat/Declaration/Value.hs-boot
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Value.hs-boot
@@ -0,0 +1,21 @@
+module Ormolu.Printer.Meat.Declaration.Value
+  ( p_valDecl,
+    p_pat,
+    p_hsExpr,
+    p_hsSplice,
+    p_stringLit,
+  )
+where
+
+import GHC
+import Ormolu.Printer.Combinators
+
+p_valDecl :: HsBindLR GhcPs GhcPs -> R ()
+
+p_pat :: Pat GhcPs -> R ()
+
+p_hsExpr :: HsExpr GhcPs -> R ()
+
+p_hsSplice :: HsSplice GhcPs -> R ()
+
+p_stringLit :: String -> R ()
diff --git a/src/Ormolu/Printer/Meat/Declaration/Warning.hs b/src/Ormolu/Printer/Meat/Declaration/Warning.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Declaration/Warning.hs
@@ -0,0 +1,51 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+module Ormolu.Printer.Meat.Declaration.Warning
+  ( p_warnDecls,
+    p_moduleWarning,
+  )
+where
+
+import BasicTypes
+import Data.Foldable
+import Data.Text (Text)
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import Ormolu.Utils
+
+p_warnDecls :: WarnDecls GhcPs -> R ()
+p_warnDecls (Warnings NoExt _ warnings) =
+  traverse_ (located' p_warnDecl) warnings
+p_warnDecls XWarnDecls {} = notImplemented "XWarnDecls"
+
+p_warnDecl :: WarnDecl GhcPs -> R ()
+p_warnDecl (Warning NoExt functions warningTxt) =
+  p_topLevelWarning functions warningTxt
+p_warnDecl XWarnDecl {} = notImplemented "XWarnDecl"
+
+p_moduleWarning :: WarningTxt -> R ()
+p_moduleWarning wtxt = do
+  let (pragmaText, lits) = warningText wtxt
+  switchLayout (getLoc <$> lits) $ do
+    inci $ pragma pragmaText (inci $ p_lits lits)
+
+p_topLevelWarning :: [Located RdrName] -> WarningTxt -> R ()
+p_topLevelWarning fnames wtxt = do
+  let (pragmaText, lits) = warningText wtxt
+  switchLayout (fmap getLoc fnames ++ fmap getLoc lits) $ do
+    pragma pragmaText . inci $ do
+      sitcc $ sep (comma >> breakpoint) p_rdrName fnames
+      breakpoint
+      p_lits lits
+
+warningText :: WarningTxt -> (Text, [Located StringLiteral])
+warningText = \case
+  WarningTxt _ lits -> ("WARNING", lits)
+  DeprecatedTxt _ lits -> ("DEPRECATED", lits)
+
+p_lits :: [Located StringLiteral] -> R ()
+p_lits = \case
+  [l] -> atom l
+  ls -> brackets N . sitcc $ sep (comma >> breakpoint) atom ls
diff --git a/src/Ormolu/Printer/Meat/ImportExport.hs b/src/Ormolu/Printer/Meat/ImportExport.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/ImportExport.hs
@@ -0,0 +1,117 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Rendering of import and export lists.
+module Ormolu.Printer.Meat.ImportExport
+  ( p_hsmodExports,
+    p_hsmodImport,
+  )
+where
+
+import Control.Monad
+import GHC
+import HsImpExp (IE (..))
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import Ormolu.Utils
+
+p_hsmodExports :: [LIE GhcPs] -> R ()
+p_hsmodExports [] = do
+  txt "("
+  breakpoint'
+  txt ")"
+p_hsmodExports xs =
+  parens N . sitcc $ do
+    layout <- getLayout
+    sep breakpoint (sitcc . located' (uncurry (p_lie layout))) (attachPositions xs)
+
+p_hsmodImport :: ImportDecl GhcPs -> R ()
+p_hsmodImport ImportDecl {..} = do
+  txt "import"
+  space
+  when ideclSource (txt "{-# SOURCE #-}")
+  space
+  when ideclSafe (txt "safe")
+  space
+  when ideclQualified (txt "qualified")
+  space
+  case ideclPkgQual of
+    Nothing -> return ()
+    Just slit -> atom slit
+  space
+  inci $ do
+    located ideclName atom
+    case ideclAs of
+      Nothing -> return ()
+      Just l -> do
+        space
+        txt "as"
+        space
+        located l atom
+    space
+    case ideclHiding of
+      Nothing -> return ()
+      Just (hiding, _) ->
+        when hiding (txt "hiding")
+    case ideclHiding of
+      Nothing -> return ()
+      Just (_, (L _ xs)) -> do
+        breakpoint
+        parens N . sitcc $ do
+          layout <- getLayout
+          sep breakpoint (sitcc . located' (uncurry (p_lie layout))) (attachPositions xs)
+    newline
+p_hsmodImport (XImportDecl NoExt) = notImplemented "XImportDecl"
+
+p_lie :: Layout -> (Int, Int) -> IE GhcPs -> R ()
+p_lie encLayout (i, totalItems) = \case
+  IEVar NoExt l1 -> do
+    located l1 p_ieWrappedName
+    p_comma
+  IEThingAbs NoExt l1 -> do
+    located l1 p_ieWrappedName
+    p_comma
+  IEThingAll NoExt l1 -> do
+    located l1 p_ieWrappedName
+    space
+    txt "(..)"
+    p_comma
+  IEThingWith NoExt l1 w xs _ -> sitcc $ do
+    located l1 p_ieWrappedName
+    breakpoint
+    inci $ do
+      let names :: [R ()]
+          names = located' p_ieWrappedName <$> xs
+      parens N . sitcc
+        $ sep (comma >> breakpoint) sitcc
+        $ case w of
+          NoIEWildcard -> names
+          IEWildcard n ->
+            let (before, after) = splitAt n names
+             in before ++ [txt ".."] ++ after
+    p_comma
+  IEModuleContents NoExt l1 -> do
+    located l1 p_hsmodName
+    p_comma
+  IEGroup NoExt n str -> do
+    unless (i == 0) newline
+    p_hsDocString (Asterisk n) False (noLoc str)
+  IEDoc NoExt str ->
+    p_hsDocString Pipe False (noLoc str)
+  IEDocNamed NoExt str -> p_hsDocName str
+  XIE NoExt -> notImplemented "XIE"
+  where
+    p_comma =
+      case encLayout of
+        SingleLine -> unless (i + 1 == totalItems) comma
+        MultiLine -> comma
+
+-- | Attach positions to 'Located' things in a list.
+attachPositions ::
+  [Located a] ->
+  [Located ((Int, Int), a)]
+attachPositions xs =
+  let f i (L l x) = L l ((i, n), x)
+      n = length xs
+   in zipWith f [0 ..] xs
diff --git a/src/Ormolu/Printer/Meat/Module.hs b/src/Ormolu/Printer/Meat/Module.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Module.hs
@@ -0,0 +1,56 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Rendering of modules.
+module Ormolu.Printer.Meat.Module
+  ( p_hsModule,
+  )
+where
+
+import Control.Monad
+import GHC
+import Ormolu.Imports
+import Ormolu.Parser.Pragma
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Comments
+import Ormolu.Printer.Meat.Common
+import Ormolu.Printer.Meat.Declaration
+import Ormolu.Printer.Meat.Declaration.Warning
+import Ormolu.Printer.Meat.ImportExport
+import Ormolu.Printer.Meat.Pragma
+
+p_hsModule :: [Pragma] -> ParsedSource -> R ()
+p_hsModule pragmas (L moduleSpan HsModule {..}) = do
+  -- NOTE If span of exports in multiline, the whole thing is multiline.
+  -- This is especially important because span of module itself always seems
+  -- to have length zero, so it's not reliable for layout selection.
+  let exportSpans = maybe [] (\(L s _) -> [s]) hsmodExports
+      deprecSpan = maybe [] (\(L s _) -> [s]) hsmodDeprecMessage
+      spans' = exportSpans ++ deprecSpan ++ [moduleSpan]
+  switchLayout spans' $ do
+    p_pragmas pragmas
+    newline
+    forM_ hsmodHaddockModHeader (p_hsDocString Pipe True)
+    case hsmodName of
+      Nothing -> return ()
+      Just hsmodName' -> do
+        located hsmodName' p_hsmodName
+        forM_ hsmodDeprecMessage $ \w -> do
+          breakpoint
+          located' p_moduleWarning w
+        case hsmodExports of
+          Nothing -> return ()
+          Just hsmodExports' -> do
+            breakpoint
+            inci (p_hsmodExports (unLoc hsmodExports'))
+        breakpoint
+        txt "where"
+        newline
+    newline
+    forM_ (sortImports hsmodImports) (located' p_hsmodImport)
+    newline
+    switchLayout (getLoc <$> hsmodDecls) $ do
+      p_hsDecls Free hsmodDecls
+      newline
+      spitRemainingComments
diff --git a/src/Ormolu/Printer/Meat/Pragma.hs b/src/Ormolu/Printer/Meat/Pragma.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Pragma.hs
@@ -0,0 +1,37 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TupleSections #-}
+
+-- | Pretty-printing of language pragmas.
+module Ormolu.Printer.Meat.Pragma
+  ( p_pragmas,
+  )
+where
+
+import qualified Data.Set as S
+import qualified Data.Text as T
+import Ormolu.Parser.Pragma (Pragma (..))
+import Ormolu.Printer.Combinators
+
+data PragmaTy = Language | OptionsGHC | OptionsHaddock
+  deriving (Eq, Ord)
+
+p_pragmas :: [Pragma] -> R ()
+p_pragmas ps =
+  let prepare = concatMap $ \case
+        PragmaLanguage xs -> (Language,) <$> xs
+        PragmaOptionsGHC x -> [(OptionsGHC, x)]
+        PragmaOptionsHaddock x -> [(OptionsHaddock, x)]
+   in mapM_ (uncurry p_pragma) (S.toAscList . S.fromList . prepare $ ps)
+
+p_pragma :: PragmaTy -> String -> R ()
+p_pragma ty c = do
+  txt "{-# "
+  txt $ case ty of
+    Language -> "LANGUAGE"
+    OptionsGHC -> "OPTIONS_GHC"
+    OptionsHaddock -> "OPTIONS_HADDOCK"
+  space
+  txt (T.pack c)
+  txt " #-}"
+  newline
diff --git a/src/Ormolu/Printer/Meat/Type.hs b/src/Ormolu/Printer/Meat/Type.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Meat/Type.hs
@@ -0,0 +1,234 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+-- | Rendering of types.
+module Ormolu.Printer.Meat.Type
+  ( p_hsType,
+    hasDocStrings,
+    p_hsContext,
+    p_hsTyVarBndr,
+    p_conDeclFields,
+    tyVarsToTypes,
+  )
+where
+
+import BasicTypes
+import GHC
+import Ormolu.Printer.Combinators
+import Ormolu.Printer.Meat.Common
+import {-# SOURCE #-} Ormolu.Printer.Meat.Declaration.Value (p_hsSplice, p_stringLit)
+import Ormolu.Printer.Operators
+import Ormolu.Utils
+
+p_hsType :: HsType GhcPs -> R ()
+p_hsType t = p_hsType' (hasDocStrings t) t
+
+p_hsType' :: Bool -> HsType GhcPs -> R ()
+p_hsType' multilineArgs = \case
+  HsForAllTy NoExt bndrs t -> do
+    txt "forall "
+    sep space (located' p_hsTyVarBndr) bndrs
+    txt "."
+    interArgBreak
+    p_hsType' multilineArgs (unLoc t)
+  HsQualTy NoExt qs t -> do
+    located qs p_hsContext
+    space
+    txt "=>"
+    interArgBreak
+    case unLoc t of
+      HsQualTy {} -> p_hsTypeR (unLoc t)
+      HsFunTy {} -> p_hsTypeR (unLoc t)
+      _ -> located t p_hsTypeR
+  HsTyVar NoExt p n -> do
+    case p of
+      Promoted -> do
+        txt "'"
+        case showOutputable (unLoc n) of
+          _ : '\'' : _ -> space
+          _ -> return ()
+      NotPromoted -> return ()
+    p_rdrName n
+  HsAppTy NoExt f x -> sitcc $ do
+    located f p_hsType
+    breakpoint
+    inci (located x p_hsType)
+  HsFunTy NoExt x y@(L _ y') -> do
+    located x p_hsType
+    space
+    txt "->"
+    interArgBreak
+    case y' of
+      HsFunTy {} -> p_hsTypeR y'
+      _ -> located y p_hsTypeR
+  HsListTy NoExt t ->
+    located t (brackets N . p_hsType)
+  HsTupleTy NoExt tsort xs ->
+    let parens' =
+          case tsort of
+            HsUnboxedTuple -> parensHash N
+            HsBoxedTuple -> parens N
+            HsConstraintTuple -> parens N
+            HsBoxedOrConstraintTuple -> parens N
+     in parens' . sitcc $
+          sep (comma >> breakpoint) (sitcc . located' p_hsType) xs
+  HsSumTy NoExt xs ->
+    parensHash N . sitcc $
+      sep (txt "|" >> breakpoint) (sitcc . located' p_hsType) xs
+  HsOpTy NoExt x op y -> sitcc $ do
+    let opTree = OpBranch (tyOpTree x) op (tyOpTree y)
+     in p_tyOpTree (reassociateOpTree Just opTree)
+  HsParTy NoExt (L _ t@HsKindSig {}) ->
+    -- NOTE Kind signatures already put parentheses around in all cases, so
+    -- skip this layer of parentheses. The reason for this behavior is that
+    -- parentheses are not always encoded with 'HsParTy', but seem to be
+    -- always necessary when we have kind signatures in place.
+    p_hsType t
+  HsParTy NoExt t ->
+    parens N (located t p_hsType)
+  HsIParamTy NoExt n t -> sitcc $ do
+    located n atom
+    space
+    txt "::"
+    breakpoint
+    inci (located t p_hsType)
+  HsStarTy NoExt _ -> txt "*"
+  HsKindSig NoExt t k ->
+    -- NOTE Also see the comment for 'HsParTy'.
+    parens N . sitcc $ do
+      located t p_hsType
+      space -- FIXME
+      txt "::"
+      space
+      inci (located k p_hsType)
+  HsSpliceTy NoExt splice -> p_hsSplice splice
+  HsDocTy NoExt t str -> do
+    p_hsDocString Pipe True str
+    located t p_hsType
+  HsBangTy NoExt (HsSrcBang _ u s) t -> do
+    case u of
+      SrcUnpack -> txt "{-# UNPACK #-}" >> space
+      SrcNoUnpack -> txt "{-# NOUNPACK #-}" >> space
+      NoSrcUnpack -> return ()
+    case s of
+      SrcLazy -> txt "~"
+      SrcStrict -> txt "!"
+      NoSrcStrict -> return ()
+    located t p_hsType
+  HsRecTy NoExt fields ->
+    p_conDeclFields fields
+  HsExplicitListTy NoExt p xs -> do
+    case p of
+      Promoted -> txt "'"
+      NotPromoted -> return ()
+    brackets N $ do
+      -- If both this list itself and the first element is promoted,
+      -- we need to put a space in between or it fails to parse.
+      case (p, xs) of
+        (Promoted, ((L _ t) : _)) | isPromoted t -> space
+        _ -> return ()
+      sitcc $ sep (comma >> breakpoint) (sitcc . located' p_hsType) xs
+  HsExplicitTupleTy NoExt xs -> do
+    txt "'"
+    parens N $ do
+      case xs of
+        ((L _ t) : _) | isPromoted t -> space
+        _ -> return ()
+      sep (comma >> breakpoint) (located' p_hsType) xs
+  HsTyLit NoExt t ->
+    case t of
+      HsStrTy (SourceText s) _ -> p_stringLit s
+      a -> atom a
+  HsWildCardTy NoExt -> txt "_"
+  XHsType (NHsCoreTy t) -> atom t
+  where
+    isPromoted = \case
+      HsTyVar _ Promoted _ -> True
+      HsExplicitListTy _ _ _ -> True
+      HsExplicitTupleTy _ _ -> True
+      _ -> False
+    interArgBreak =
+      if multilineArgs
+        then newline
+        else breakpoint
+    p_hsTypeR = p_hsType' multilineArgs
+
+-- | Return 'True' if at least one argument in 'HsType' has a doc string
+-- attached to it.
+hasDocStrings :: HsType GhcPs -> Bool
+hasDocStrings = \case
+  HsDocTy _ _ _ -> True
+  HsFunTy _ (L _ x) (L _ y) -> hasDocStrings x || hasDocStrings y
+  _ -> False
+
+p_hsContext :: HsContext GhcPs -> R ()
+p_hsContext = \case
+  [] -> txt "()"
+  [x] -> located x p_hsType
+  xs ->
+    parens N . sitcc $
+      sep (comma >> breakpoint) (sitcc . located' p_hsType) xs
+
+p_hsTyVarBndr :: HsTyVarBndr GhcPs -> R ()
+p_hsTyVarBndr = \case
+  UserTyVar NoExt x ->
+    p_rdrName x
+  KindedTyVar NoExt l k -> parens N $ do
+    located l atom
+    space
+    txt "::"
+    breakpoint
+    inci (located k p_hsType)
+  XTyVarBndr NoExt -> notImplemented "XTyVarBndr"
+
+p_conDeclFields :: [LConDeclField GhcPs] -> R ()
+p_conDeclFields xs =
+  braces N . sitcc $
+    sep (comma >> breakpoint) (sitcc . located' p_conDeclField) xs
+
+p_conDeclField :: ConDeclField GhcPs -> R ()
+p_conDeclField ConDeclField {..} = do
+  mapM_ (p_hsDocString Pipe True) cd_fld_doc
+  sitcc $
+    sep
+      (comma >> breakpoint)
+      (located' (p_rdrName . rdrNameFieldOcc))
+      cd_fld_names
+  space
+  txt "::"
+  breakpoint
+  sitcc . inci $ p_hsType (unLoc cd_fld_type)
+p_conDeclField (XConDeclField NoExt) = notImplemented "XConDeclField"
+
+tyOpTree :: LHsType GhcPs -> OpTree (LHsType GhcPs) (Located RdrName)
+tyOpTree (L _ (HsOpTy NoExt l op r)) =
+  OpBranch (tyOpTree l) op (tyOpTree r)
+tyOpTree n = OpNode n
+
+p_tyOpTree :: OpTree (LHsType GhcPs) (Located RdrName) -> R ()
+p_tyOpTree (OpNode n) = located n p_hsType
+p_tyOpTree (OpBranch l op r) = do
+  switchLayout [opTreeLoc l] $ do
+    p_tyOpTree l
+  breakpoint
+  inci . switchLayout [opTreeLoc r] $ do
+    p_rdrName op
+    space
+    p_tyOpTree r
+
+----------------------------------------------------------------------------
+-- Conversion functions
+
+tyVarsToTypes :: LHsQTyVars GhcPs -> [LHsType GhcPs]
+tyVarsToTypes = \case
+  HsQTvs {..} -> fmap tyVarToType <$> hsq_explicit
+  XLHsQTyVars {} -> notImplemented "XLHsQTyVars"
+
+tyVarToType :: HsTyVarBndr GhcPs -> HsType GhcPs
+tyVarToType = \case
+  UserTyVar NoExt tvar -> HsTyVar NoExt NotPromoted tvar
+  KindedTyVar NoExt tvar kind ->
+    HsParTy NoExt $ noLoc $
+      HsKindSig NoExt (noLoc (HsTyVar NoExt NotPromoted tvar)) kind
+  XTyVarBndr {} -> notImplemented "XTyVarBndr"
diff --git a/src/Ormolu/Printer/Operators.hs b/src/Ormolu/Printer/Operators.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/Operators.hs
@@ -0,0 +1,182 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+
+-- | This module helps handle operator chains composed of different
+-- operators that may have different precedence and fixities.
+module Ormolu.Printer.Operators
+  ( OpTree (..),
+    opTreeLoc,
+    reassociateOpTree,
+  )
+where
+
+import BasicTypes (Fixity (..), SourceText (NoSourceText), compareFixity, defaultFixity)
+import Data.Function (on)
+import Data.List
+import Data.Maybe (fromMaybe)
+import GHC
+import OccName (mkVarOcc)
+import RdrName (mkRdrUnqual)
+import SrcLoc (combineSrcSpans)
+
+-- | Intermediate representation of operator trees. It has two type
+-- parameters: @ty@ is the type of sub-expressions, while @op@ is the type
+-- of operators.
+data OpTree ty op
+  = OpNode ty
+  | OpBranch
+      (OpTree ty op)
+      op
+      (OpTree ty op)
+
+-- | Return combined 'SrcSpan's of all elements in this 'OpTree'.
+opTreeLoc :: OpTree (Located a) b -> SrcSpan
+opTreeLoc (OpNode (L l _)) = l
+opTreeLoc (OpBranch l _ r) = combineSrcSpans (opTreeLoc l) (opTreeLoc r)
+
+-- | Re-associate an 'OpTree' taking into account automagically inferred
+-- relative precedence of operators. Users are expected to first construct
+-- an initial 'OpTree', then re-associate it using this function before
+-- printing.
+reassociateOpTree ::
+  -- | How to get name of an operator
+  (op -> Maybe RdrName) ->
+  -- | Original 'OpTree'
+  OpTree (Located ty) (Located op) ->
+  -- | Re-associated 'OpTree'
+  OpTree (Located ty) (Located op)
+reassociateOpTree getOpName opTree =
+  reassociateOpTreeWith
+    (buildFixityMap getOpName normOpTree)
+    (getOpName . unLoc)
+    normOpTree
+  where
+    normOpTree = normalizeOpTree opTree
+
+-- | Re-associate an 'OpTree' given the map with operator fixities.
+reassociateOpTreeWith ::
+  forall ty op.
+  -- | Fixity map for operators
+  [(RdrName, Fixity)] ->
+  -- | How to get the name of an operator
+  (op -> Maybe RdrName) ->
+  -- | Original 'OpTree'
+  OpTree ty op ->
+  -- | Re-associated 'OpTree'
+  OpTree ty op
+reassociateOpTreeWith fixityMap getOpName = go
+  where
+    fixityOf :: op -> Fixity
+    fixityOf op = fromMaybe defaultFixity $ do
+      opName <- getOpName op
+      lookup opName fixityMap
+    -- Here, left branch is already associated and the root alongside with
+    -- the right branch is right-associated. This function picks up one item
+    -- from the right and inserts it correctly to the left.
+    --
+    -- Also, we are using the 'compareFixity' function which returns if the
+    -- expression should associate to right.
+    go :: OpTree ty op -> OpTree ty op
+    -- base cases
+    go t@(OpNode _) = t
+    go t@(OpBranch (OpNode _) _ (OpNode _)) = t
+    -- shift one operator to the left at the beginning
+    go (OpBranch l@(OpNode _) op (OpBranch l' op' r')) =
+      go (OpBranch (OpBranch l op l') op' r')
+    -- at the last operator, place the operator and don't recurse
+    go (OpBranch (OpBranch l op r) op' r'@(OpNode _)) =
+      if snd $ compareFixity (fixityOf op) (fixityOf op')
+        then OpBranch l op (go $ OpBranch r op' r')
+        else OpBranch (OpBranch l op r) op' r'
+    -- else, shift one operator to left and recurse.
+    go (OpBranch (OpBranch l op r) op' (OpBranch l' op'' r')) =
+      if snd $ compareFixity (fixityOf op) (fixityOf op')
+        then go $ OpBranch (OpBranch l op (go $ OpBranch r op' l')) op'' r'
+        else go $ OpBranch (OpBranch (OpBranch l op r) op' l') op'' r'
+
+-- | Build a map of inferred 'Fixity's from an 'OpTree'.
+buildFixityMap ::
+  forall ty op.
+  -- | How to get the name of an operator
+  (op -> Maybe RdrName) ->
+  -- | Operator tree
+  OpTree (Located ty) (Located op) ->
+  -- | Fixity map
+  [(RdrName, Fixity)]
+buildFixityMap getOpName opTree =
+  concatMap (\(i, ns) -> map (\(n, _) -> (n, fixity i InfixL)) ns)
+    . zip [0 ..]
+    . groupBy (doubleWithinEps 0.00001 `on` snd)
+    . (overrides ++)
+    . avgScores
+    $ score opTree
+  where
+    -- Add a special case for ($), since it is pretty unlikely for someone
+    -- to override it.
+    overrides :: [(RdrName, Double)]
+    overrides =
+      [ (mkRdrUnqual $ mkVarOcc "$", -1)
+      ]
+    -- Assign scores to operators based on their location in the source.
+    score :: OpTree (Located ty) (Located op) -> [(RdrName, Double)]
+    score (OpNode _) = []
+    score (OpBranch l o r) = fromMaybe (score r) $ do
+      -- If we fail to get any of these, 'defaultFixity' will be used by
+      -- 'reassociateOpTreeWith'.
+      le <- srcSpanEndLine <$> unSrcSpan (opTreeLoc l) -- left end
+      ob <- srcSpanStartLine <$> unSrcSpan (getLoc o) -- operator begin
+      oe <- srcSpanEndLine <$> unSrcSpan (getLoc o) -- operator end
+      rb <- srcSpanStartLine <$> unSrcSpan (opTreeLoc r) -- right begin
+      oc <- srcSpanStartCol <$> unSrcSpan (getLoc o) -- operator column
+      opName <- getOpName (unLoc o)
+      let s =
+            if le < ob
+              then-- if the operator is in the beginning of a line, assign
+              -- a score relative to its column within range [0, 1).
+                fromIntegral oc / fromIntegral (maxCol + 1)
+              else-- if the operator is in the end of the line, assign the
+              -- score 1.
+
+                if oe < rb
+                  then 1
+                  else 2 -- otherwise, assign a high score.
+      return $ (opName, s) : score r
+    avgScores :: [(RdrName, Double)] -> [(RdrName, Double)]
+    avgScores =
+      sortOn snd
+        . map (\xs@((n, _) : _) -> (n, avg $ map snd xs))
+        . groupBy ((==) `on` fst)
+        . sort
+    avg :: [Double] -> Double
+    avg i = sum i / fromIntegral (length i)
+    -- The start column of the rightmost operator.
+    maxCol = go opTree
+      where
+        go (OpNode (L _ _)) = 0
+        go (OpBranch l (L o _) r) =
+          maximum
+            [ go l,
+              maybe 0 srcSpanStartCol (unSrcSpan o),
+              go r
+            ]
+    unSrcSpan (RealSrcSpan r) = Just r
+    unSrcSpan (UnhelpfulSpan _) = Nothing
+
+----------------------------------------------------------------------------
+-- Helpers
+
+-- | Convert an 'OpTree' to with all operators having the same fixity and
+-- associativity (left infix).
+normalizeOpTree :: OpTree ty op -> OpTree ty op
+normalizeOpTree (OpNode n) =
+  OpNode n
+normalizeOpTree (OpBranch (OpNode l) lop r) =
+  OpBranch (OpNode l) lop (normalizeOpTree r)
+normalizeOpTree (OpBranch (OpBranch l' lop' r') lop r) =
+  normalizeOpTree (OpBranch l' lop' (OpBranch r' lop r))
+
+fixity :: Int -> FixityDirection -> Fixity
+fixity = Fixity NoSourceText
+
+doubleWithinEps :: Double -> Double -> Double -> Bool
+doubleWithinEps eps a b = abs (a - b) < eps
diff --git a/src/Ormolu/Printer/SpanStream.hs b/src/Ormolu/Printer/SpanStream.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Printer/SpanStream.hs
@@ -0,0 +1,46 @@
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+
+-- | Build span stream from AST.
+module Ormolu.Printer.SpanStream
+  ( SpanStream (..),
+    mkSpanStream,
+  )
+where
+
+import Data.DList (DList)
+import qualified Data.DList as D
+import Data.Data (Data)
+import Data.Generics (everything, ext2Q)
+import Data.List (sortOn)
+import Data.Typeable (cast)
+import SrcLoc
+
+-- | A stream of 'RealSrcSpan's in ascending order. This allows us to tell
+-- e.g. whether there is another \"located\" element of AST between current
+-- element and comment we're considering for printing.
+newtype SpanStream = SpanStream [RealSrcSpan]
+  deriving (Eq, Show, Data, Semigroup, Monoid)
+
+-- | Create 'SpanStream' from a data structure containing \"located\"
+-- elements.
+mkSpanStream ::
+  Data a =>
+  -- | Data structure to inspect (AST)
+  a ->
+  SpanStream
+mkSpanStream a =
+  SpanStream
+    . sortOn realSrcSpanStart
+    . D.toList
+    $ everything mappend (const mempty `ext2Q` queryLocated) a
+  where
+    queryLocated ::
+      (Data e0, Data e1) =>
+      GenLocated e0 e1 ->
+      DList RealSrcSpan
+    queryLocated (L mspn _) =
+      case cast mspn :: Maybe SrcSpan of
+        Nothing -> mempty
+        Just (UnhelpfulSpan _) -> mempty
+        Just (RealSrcSpan spn) -> D.singleton spn
diff --git a/src/Ormolu/Utils.hs b/src/Ormolu/Utils.hs
new file mode 100644
--- /dev/null
+++ b/src/Ormolu/Utils.hs
@@ -0,0 +1,74 @@
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+-- | Random utilities used by the code.
+module Ormolu.Utils
+  ( combineSrcSpans',
+    isModule,
+    notImplemented,
+    showOutputable,
+    splitDocString,
+  )
+where
+
+import Data.Data (Data, showConstr, toConstr)
+import Data.List (dropWhileEnd)
+import Data.List.NonEmpty (NonEmpty (..))
+import Data.Text (Text)
+import qualified Data.Text as T
+import HsDoc (HsDocString, unpackHDS)
+import qualified Outputable as GHC
+import SrcLoc
+
+-- | Combine all source spans from the given list.
+combineSrcSpans' :: NonEmpty SrcSpan -> SrcSpan
+combineSrcSpans' (x :| xs) = foldr combineSrcSpans x xs
+
+-- | Return 'True' if given element of AST is module.
+isModule :: Data a => a -> Bool
+isModule x = showConstr (toConstr x) == "HsModule"
+
+-- | Placeholder for things that are not yet implemented.
+notImplemented :: String -> a
+notImplemented msg = error $ "not implemented yet: " ++ msg
+
+-- | Pretty-print an 'GHC.Outputable' thing.
+showOutputable :: GHC.Outputable o => o -> String
+showOutputable = GHC.showSDocUnsafe . GHC.ppr
+
+-- | Split and normalize a doc string. The result is a list of lines that
+-- make up the comment.
+splitDocString :: HsDocString -> [Text]
+splitDocString docStr =
+  case r of
+    [] -> [""]
+    _ -> r
+  where
+    r =
+      fmap escapeLeadingDollar
+        . dropPaddingSpace
+        . dropWhileEnd T.null
+        . fmap (T.stripEnd . T.pack)
+        . lines
+        $ unpackHDS docStr
+    -- We cannot have the first character to be a dollar because in that
+    -- case it'll be a parse error (apparently collides with named docs
+    -- syntax @-- $name@ somehow).
+    escapeLeadingDollar txt =
+      case T.uncons txt of
+        Just ('$', _) -> T.cons '\\' txt
+        _ -> txt
+    dropPaddingSpace xs =
+      case dropWhile T.null xs of
+        [] -> []
+        (x : _) ->
+          let leadingSpace txt = case T.uncons txt of
+                Just (' ', _) -> True
+                _ -> False
+              dropSpace txt =
+                if leadingSpace txt
+                  then T.drop 1 txt
+                  else txt
+           in if leadingSpace x
+                then dropSpace <$> xs
+                else xs
diff --git a/tests/Ormolu/Parser/PragmaSpec.hs b/tests/Ormolu/Parser/PragmaSpec.hs
new file mode 100644
--- /dev/null
+++ b/tests/Ormolu/Parser/PragmaSpec.hs
@@ -0,0 +1,26 @@
+module Ormolu.Parser.PragmaSpec (spec) where
+
+import Ormolu.Parser.Pragma
+import Test.Hspec
+
+spec :: Spec
+spec = do
+  describe "parsePragma" $ do
+    stdTest "{-# LANGUAGE Foo #-}" (Just (PragmaLanguage ["Foo"]))
+    stdTest "{-# language Foo #-}" (Just (PragmaLanguage ["Foo"]))
+    stdTest "{-#LANGUAGE Foo#-}" (Just (PragmaLanguage ["Foo"]))
+    stdTest "{-# LANGUAGE Foo#-}" (Just (PragmaLanguage ["Foo"]))
+    stdTest "{-#language Foo#-}" (Just (PragmaLanguage ["Foo"]))
+    stdTest "{-# lAngUAGe Foo #-}" (Just (PragmaLanguage ["Foo"]))
+    stdTest "{-# LANGUAGE Foo, Bar #-}" (Just (PragmaLanguage ["Foo", "Bar"]))
+    stdTest "{-# LANGUAGE Foo Bar #-}" Nothing
+    stdTest "{-# BOO Foo #-}" Nothing
+    stdTest "something" Nothing
+    stdTest "{-# LANGUAGE foo, Bar #-}" Nothing
+    stdTest "{-# OPTIONS_GHC foo bar baz  #-}" (Just $ PragmaOptionsGHC "foo bar baz")
+    stdTest "{-#OPTIONS_HADDOCK foo, bar, baz  #-}" (Just $ PragmaOptionsHaddock "foo, bar, baz")
+
+stdTest :: String -> Maybe Pragma -> Spec
+stdTest input result =
+  it input $
+    parsePragma input `shouldBe` result
diff --git a/tests/Ormolu/PrinterSpec.hs b/tests/Ormolu/PrinterSpec.hs
new file mode 100644
--- /dev/null
+++ b/tests/Ormolu/PrinterSpec.hs
@@ -0,0 +1,94 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+module Ormolu.PrinterSpec
+  ( spec,
+  )
+where
+
+import Control.Exception
+import Control.Monad
+import Control.Monad.IO.Class
+import Data.List (isSuffixOf)
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified Data.Text.IO as T
+import Ormolu
+import Path
+import Path.IO
+import System.FilePath (addExtension, dropExtensions, splitExtensions)
+import Test.Hspec
+
+spec :: Spec
+spec = do
+  es <- runIO locateExamples
+  forM_ es checkExample
+
+-- | Check a single given example.
+checkExample :: Path Rel File -> Spec
+checkExample srcPath' = it (fromRelFile srcPath' ++ " works") . withNiceExceptions $ do
+  let srcPath = examplesDir </> srcPath'
+  expectedOutputPath <- deriveOutput srcPath
+  -- 1. Given input snippet of source code parse it and pretty print it.
+  -- 2. Parse the result of pretty-printing again and make sure that AST
+  -- is the same as AST of the original snippet. (This happens in
+  -- 'ormoluFile' automatically.)
+  formatted0 <- ormoluFile defaultConfig (fromRelFile srcPath)
+  -- 3. Check the output against expected output. Thus all tests should
+  -- include two files: input and expected output.
+  -- T.writeFile (fromRelFile expectedOutputPath) formatted0
+  expected <- (liftIO . T.readFile . fromRelFile) expectedOutputPath
+  shouldMatch False formatted0 expected
+  -- 4. Check that running the formatter on the output produces the same
+  -- output again (the transformation is idempotent).
+  formatted1 <- ormolu defaultConfig "<formatted>" (T.unpack formatted0)
+  shouldMatch True formatted1 formatted0
+
+-- | Build list of examples for testing.
+locateExamples :: IO [Path Rel File]
+locateExamples =
+  filter isInput . snd <$> listDirRecurRel examplesDir
+
+-- | Does given path look like input path (as opposed to expected output
+-- path)?
+isInput :: Path Rel File -> Bool
+isInput path =
+  let s = fromRelFile path
+      (s', exts) = splitExtensions s
+   in exts == ".hs" && not ("-out" `isSuffixOf` s')
+
+-- | For given path of input file return expected name of output.
+deriveOutput :: Path Rel File -> IO (Path Rel File)
+deriveOutput path =
+  parseRelFile $
+    addExtension (dropExtensions (fromRelFile path) ++ "-out") "hs"
+
+-- | A version of 'shouldBe' that is specialized to comparing 'Text' values.
+-- It also prints multi-line snippets in a more readable form.
+shouldMatch :: Bool -> Text -> Text -> Expectation
+shouldMatch idempotencyTest actual expected =
+  when (actual /= expected) . expectationFailure $
+    unlines
+      [ ">>>>>>>>>>>>>>>>>>>>>> expected (" ++ pass ++ "):",
+        T.unpack expected,
+        ">>>>>>>>>>>>>>>>>>>>>> but got:",
+        T.unpack actual
+      ]
+  where
+    pass =
+      if idempotencyTest
+        then "idempotency pass"
+        else "first pass"
+
+examplesDir :: Path Rel Dir
+examplesDir = $(mkRelDir "data/examples")
+
+-- | Inside this wrapper 'OrmoluException' will be caught and displayed
+-- nicely using 'displayException'.
+withNiceExceptions ::
+  -- | Action that may throw the exception
+  Expectation ->
+  Expectation
+withNiceExceptions m = m `catch` h
+  where
+    h :: OrmoluException -> IO ()
+    h = expectationFailure . displayException
diff --git a/tests/Spec.hs b/tests/Spec.hs
new file mode 100644
--- /dev/null
+++ b/tests/Spec.hs
@@ -0,0 +1,1 @@
+{-# OPTIONS_GHC -F -pgmF hspec-discover #-}