diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,37 @@
+## Ormolu 0.0.4.0
+
+* When given several files to format, Ormolu does not stop on the first
+  failure, but tries to format all the files. [Issue
+  502](https://github.com/tweag/ormolu/issues/502).
+
+* Made rendering of pattern matches involving operators consistent with
+  other cases of rendering of operators. [Issue
+  500](https://github.com/tweag/ormolu/issues/500).
+
+* More compact rendering of type family injectivity constraints. [Issue
+  482](https://github.com/tweag/ormolu/issues/482).
+
+* Improved rendering of the keyword `where` in class, data, and type family
+  declarations. When headers of these declarations are multi-line `where` is
+  now put on its own line. [Issue
+  509](https://github.com/tweag/ormolu/issues/509).
+
+* Fixed the bug pertaining to rendering of arrow notation with multiline
+  expressions. [Issue 513](https://github.com/tweag/ormolu/issues/513).
+
+* Made rendering of data type definitions, value-level applications, and
+  application of types use the same style. Moreover, existential now doesn't
+  cause the data constructor be unconditionally rendered in multiline
+  layout. [Issue 427](https://github.com/tweag/ormolu/issues/427).
+
+* Records with a single data constructor are now formatted more compactly.
+  [Issue 425](https://github.com/tweag/ormolu/issues/425).
+
+* Switched to `ghc-lib-parser-8.10.1`.
+
+* Implemented support for the new language extensions `ImportQualifiedPost`
+  and `StandaloneKindSignatures`.
+
 ## Ormolu 0.0.3.1
 
 * Fixed rendering of record updates with the record dot preprocessor syntax
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 [![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)
+[![Build status](https://badge.buildkite.com/8e3b0951f3652b77e1c422b361904136a539b0522029156354.svg?branch=master)](https://buildkite.com/tweag-1/ormolu)
 
 Ormolu is a formatter for Haskell source code. The project was created with
 the following goals in mind:
@@ -104,6 +104,7 @@
 
 * [Emacs][emacs-package]
 * [VS Code][vs-code-plugin]
+* vim: [neoformat][neoformat], [vim-ormolu][vim-ormolu]
 
 ## Running on Hackage
 
@@ -135,3 +136,5 @@
 [haskell-src-exts]: https://hackage.haskell.org/package/haskell-src-exts
 [emacs-package]: https://github.com/vyorkin/ormolu.el
 [vs-code-plugin]: https://marketplace.visualstudio.com/items?itemName=sjurmillidahl.ormolu-vscode
+[vim-ormolu]: https://github.com/sdiehl/vim-ormolu
+[neoformat]: https://github.com/sbdchd/neoformat
diff --git a/app/Main.hs b/app/Main.hs
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -1,12 +1,19 @@
-{-# LANGUAGE CPP             #-}
-{-# LANGUAGE LambdaCase      #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE TypeApplications #-}
 
-module Main (main) where
+module Main
+  ( main,
+  )
+where
 
+import Control.Exception (SomeException, displayException, try)
 import Control.Monad
+import Data.Either (lefts)
 import Data.List (intercalate, sort)
+import qualified Data.Text.IO as TIO
 import Data.Version (showVersion)
 import Development.GitRev
 import Options.Applicative
@@ -16,10 +23,8 @@
 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
@@ -27,24 +32,35 @@
   case optInputFiles of
     [] -> formatOne' Nothing
     ["-"] -> formatOne' Nothing
-    xs -> mapM_ (formatOne' . Just) xs
+    [x] -> formatOne' (Just x)
+    xs -> do
+      -- It is possible to get IOException, error's and 'OrmoluException's
+      -- from 'formatOne', so we just catch everything.
+      errs <-
+        lefts <$> mapM (try @SomeException . formatOne' . Just) (sort xs)
+      unless (null errs) $ do
+        mapM_ (hPutStrLn stderr . displayException) errs
+        exitWith (ExitFailure 102)
 
 -- | Format a single input.
-
-formatOne
-  :: Mode                       -- ^ Mode of operation
-  -> Config                     -- ^ Configuration
-  -> Maybe FilePath             -- ^ File to format or stdin as 'Nothing'
-  -> IO ()
+formatOne ::
+  -- | Mode of operation
+  Mode ->
+  -- | Configuration
+  Config ->
+  -- | File to format or stdin as 'Nothing'
+  Maybe FilePath ->
+  IO ()
 formatOne mode config = \case
   Nothing -> do
     r <- ormoluStdin config
     case mode of
       Stdout -> TIO.putStr r
-      _ ->  do
-        hPutStrLn stderr
+      _ -> 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.
+        -- 101 is different from all the other exit codes we already use.
         exitWith (ExitFailure 101)
   Just inputFile -> do
     r <- ormoluFile config inputFile
@@ -65,101 +81,109 @@
 -- 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
+    optMode :: !Mode,
+    -- | Ormolu 'Config'
+    optConfig :: !Config,
+    -- | Haskell source files to format or stdin (when the list is empty)
+    optInputFiles :: ![FilePath]
   }
 
 -- | 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
+  = -- | Output formatted source code to stdout
+    Stdout
+  | -- | Overwrite original file
+    InPlace
+  | -- | Exit with non-zero status code if
+    -- source is not already formatted
+    Check
   deriving (Eq, Show)
 
 optsParserInfo :: ParserInfo Opts
-optsParserInfo = info (helper <*> ver <*> exts <*> optsParser) . mconcat $
-  [ fullDesc
-  , progDesc ""
-  , header ""
-  ]
+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
+    ver =
+      infoOption verStr . mconcat $
+        [ long "version",
+          short 'v',
+          help "Print version of the program"
         ]
-      , "using ghc-lib-parser " ++ VERSION_ghc_lib_parser
-      ]
+    verStr =
+      intercalate
+        "\n"
+        [ unwords
+            [ "ormolu",
+              showVersion version,
+              $gitBranch,
+              $gitHash
+            ],
+          "using ghc-lib-parser " ++ VERSION_ghc_lib_parser
+        ]
     exts :: Parser (a -> a)
-    exts = infoOption displayExts . mconcat $
-      [ long "manual-exts"
-      , help "Display extensions that need to be enabled manually"
-      ]
+    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
-  <$> (option parseMode . mconcat)
-    [ long "mode"
-    , short 'm'
-    , metavar "MODE"
-    , value Stdout
-    , help "Mode of operation: 'stdout' (default), 'inplace', or 'check'"
-    ]
-  <*> configParser
-  <*> (many . strArgument . mconcat)
-    [ metavar "FILE"
-    , help "Haskell source files to format or stdin (default)"
-    ]
+optsParser =
+  Opts
+    <$> (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
-  <$> (fmap (fmap DynOption) . many . strOption . mconcat)
-    [ long "ghc-opt"
-    , short 'o'
-    , metavar "OPT"
-    , help "GHC options to enable (e.g. language extensions)"
-    ]
-  <*> (switch . mconcat)
-    [ long "unsafe"
-    , short 'u'
-    , help "Do formatting faster but without automatic detection of defects"
-    ]
-  <*> (switch . mconcat)
-    [ long "debug"
-    , short 'd'
-    , help "Output information useful for debugging"
-    ]
-  <*> (switch . mconcat)
-    [ long "tolerate-cpp"
-    , short 'p'
-    , help "Do not fail if CPP pragma is present"
-    ]
-  <*> (switch . mconcat)
-    [ long "check-idempotency"
-    , short 'c'
-    , help "Fail if formatting is not idempotent"
-    ]
+configParser =
+  Config
+    <$> (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
diff --git a/data/examples/declaration/class/dependency-super-classes-out.hs b/data/examples/declaration/class/dependency-super-classes-out.hs
--- a/data/examples/declaration/class/dependency-super-classes-out.hs
+++ b/data/examples/declaration/class/dependency-super-classes-out.hs
@@ -13,7 +13,8 @@
     MonadPlus m -- Potential for failure
   ) =>
   MonadParsec e s m
-    | m -> e s where
+    | m -> e s
+  where
   -- | 'getState' returns state
   getState ::
     m s
diff --git a/data/examples/declaration/class/functional-dependencies-out.hs b/data/examples/declaration/class/functional-dependencies-out.hs
--- a/data/examples/declaration/class/functional-dependencies-out.hs
+++ b/data/examples/declaration/class/functional-dependencies-out.hs
@@ -14,5 +14,6 @@
       b c -> a d, -- Bar
       a c -> b d, -- Baz
       a c d -> b,
-      a b d -> a b c d where
+      a b d -> a b c d
+  where
   baz :: a -> b
diff --git a/data/examples/declaration/class/multi-parameters2-out.hs b/data/examples/declaration/class/multi-parameters2-out.hs
--- a/data/examples/declaration/class/multi-parameters2-out.hs
+++ b/data/examples/declaration/class/multi-parameters2-out.hs
@@ -10,7 +10,8 @@
     c -- Baz bar
     d -- Baz baz
     e -- Rest
-    f where
+    f
+  where
   barbaz ::
     a -> f
   bazbar ::
diff --git a/data/examples/declaration/data/existential-multiline-out.hs b/data/examples/declaration/data/existential-multiline-out.hs
--- a/data/examples/declaration/data/existential-multiline-out.hs
+++ b/data/examples/declaration/data/existential-multiline-out.hs
@@ -3,3 +3,15 @@
 data Foo
   = forall a. MkFoo a (a -> Bool)
   | forall a. Eq a => MkBar a
+
+data Bar
+  = forall x y.
+    Bar x y x y
+
+data Baz
+  = forall x y.
+    Baz
+      x
+      y
+      x
+      y
diff --git a/data/examples/declaration/data/existential-multiline.hs b/data/examples/declaration/data/existential-multiline.hs
--- a/data/examples/declaration/data/existential-multiline.hs
+++ b/data/examples/declaration/data/existential-multiline.hs
@@ -3,3 +3,10 @@
 data Foo
   = forall a. MkFoo a (a -> Bool)
   | forall a. Eq a => MkBar a
+
+data Bar = forall x y.
+         Bar x y x y
+
+data Baz = forall x y.
+         Baz x y x
+             y
diff --git a/data/examples/declaration/data/gadt/multiline-where-out.hs b/data/examples/declaration/data/gadt/multiline-where-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/multiline-where-out.hs
@@ -0,0 +1,7 @@
+data
+  Foo
+    a
+    b
+    c
+  where
+  Foo :: a -> b -> c -> Foo a b c
diff --git a/data/examples/declaration/data/gadt/multiline-where.hs b/data/examples/declaration/data/gadt/multiline-where.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/gadt/multiline-where.hs
@@ -0,0 +1,6 @@
+data
+  Foo
+    a
+    b
+    c where
+  Foo :: a -> b -> c -> Foo a b c
diff --git a/data/examples/declaration/data/record-multi-const-out.hs b/data/examples/declaration/data/record-multi-const-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/record-multi-const-out.hs
@@ -0,0 +1,17 @@
+module Main where
+
+-- | Something.
+data Foo
+  = Foo
+      { -- | X
+        fooX :: Int,
+        -- | Y
+        fooY :: Int
+      }
+  | Bar
+      { -- | X
+        barX :: Int,
+        -- | Y
+        barY :: Int
+      }
+  deriving (Eq, Show)
diff --git a/data/examples/declaration/data/record-multi-const.hs b/data/examples/declaration/data/record-multi-const.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/data/record-multi-const.hs
@@ -0,0 +1,13 @@
+module Main where
+
+-- | Something.
+
+data Foo = Foo
+  { fooX :: Int -- ^ X
+  , fooY :: Int -- ^ Y
+  } |
+  Bar
+  { barX :: Int -- ^ X
+  , barY :: Int -- ^ Y
+  }
+  deriving (Eq, Show)
diff --git a/data/examples/declaration/data/record-out.hs b/data/examples/declaration/data/record-out.hs
--- a/data/examples/declaration/data/record-out.hs
+++ b/data/examples/declaration/data/record-out.hs
@@ -1,24 +1,23 @@
 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
-      }
+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/simple-broken-out.hs b/data/examples/declaration/data/simple-broken-out.hs
--- a/data/examples/declaration/data/simple-broken-out.hs
+++ b/data/examples/declaration/data/simple-broken-out.hs
@@ -1,8 +1,7 @@
 module Main where
 
 -- | Here we go.
-data Foo
-  = Foo {unFoo :: Int}
+data Foo = Foo {unFoo :: Int}
   deriving (Eq)
 
 -- | And once again.
diff --git a/data/examples/declaration/instance/data-family-instances-gadt-out.hs b/data/examples/declaration/instance/data-family-instances-gadt-out.hs
--- a/data/examples/declaration/instance/data-family-instances-gadt-out.hs
+++ b/data/examples/declaration/instance/data-family-instances-gadt-out.hs
@@ -3,9 +3,11 @@
 
 data instance Bar Int a where
   SameBar ::
-    Bar Int
+    Bar
       Int
+      Int
   CloseBar :: Bar Int Double
   OtherBar ::
-    Bar Int
+    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
--- a/data/examples/declaration/instance/data-family-instances-newtype-out.hs
+++ b/data/examples/declaration/instance/data-family-instances-newtype-out.hs
@@ -1,7 +1,6 @@
 {-# LANGUAGE GADTSyntax #-}
 {-# LANGUAGE TypeFamilies #-}
 
-newtype instance Foo [Double]
-  = DoubleListFoo
-      { unDoubleListFoo :: Double
-      }
+newtype instance Foo [Double] = DoubleListFoo
+  { unDoubleListFoo :: Double
+  }
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
--- 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
@@ -1,7 +1,7 @@
 type family
   Id a =
-    result
-    | result -> a where
+    result | result -> a
+  where
   Id a =
     a
 
@@ -10,14 +10,15 @@
     (a :: k)
     b
     c =
-    foo
-    | foo -> k b where
+    foo | foo -> k b
+  where
   G a b c =
     (a, b)
 
 type family
   F a ::
-    * -> * where
+    * -> *
+  where
   F Int = Double
   F Bool =
     Char
diff --git a/data/examples/declaration/type/visible-forall-out.hs b/data/examples/declaration/type/visible-forall-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/visible-forall-out.hs
@@ -0,0 +1,2 @@
+-- source: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0081-forall-arrow.rst
+data T :: forall k -> k -> Type
diff --git a/data/examples/declaration/type/visible-forall.hs b/data/examples/declaration/type/visible-forall.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/type/visible-forall.hs
@@ -0,0 +1,2 @@
+-- source: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0081-forall-arrow.rst
+data T :: forall k -> k -> Type
diff --git a/data/examples/declaration/value/function/arrow/expression-applications-out.hs b/data/examples/declaration/value/function/arrow/expression-applications-out.hs
deleted file mode 100644
--- a/data/examples/declaration/value/function/arrow/expression-applications-out.hs
+++ /dev/null
@@ -1,9 +0,0 @@
-{-# 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
deleted file mode 100644
--- a/data/examples/declaration/value/function/arrow/expression-applications.hs
+++ /dev/null
@@ -1,9 +0,0 @@
-{-# 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
deleted file mode 100644
--- a/data/examples/declaration/value/function/arrow/expression-forms-out.hs
+++ /dev/null
@@ -1,14 +0,0 @@
-{-# 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
deleted file mode 100644
--- a/data/examples/declaration/value/function/arrow/expression-forms.hs
+++ /dev/null
@@ -1,11 +0,0 @@
-{-# 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/multiline-case-out.hs b/data/examples/declaration/value/function/arrow/multiline-case-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/multiline-case-out.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE Arrows #-}
+
+f = proc x -> do
+  x <-
+    case x of X -> x
+      -<
+        y
+  a -< b
diff --git a/data/examples/declaration/value/function/arrow/multiline-case.hs b/data/examples/declaration/value/function/arrow/multiline-case.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/declaration/value/function/arrow/multiline-case.hs
@@ -0,0 +1,7 @@
+{-# LANGUAGE Arrows #-}
+
+f = proc x -> do
+  x
+    <- case x of X -> x
+    -< y
+  a -< b
diff --git a/data/examples/declaration/value/function/arrow/proc-applications-out.hs b/data/examples/declaration/value/function/arrow/proc-applications-out.hs
--- a/data/examples/declaration/value/function/arrow/proc-applications-out.hs
+++ b/data/examples/declaration/value/function/arrow/proc-applications-out.hs
@@ -9,10 +9,11 @@
       w
       )
   ->
-    f -< -- The value
-      ( x, -- Foo
-        w, -- Bar
-        z -- Baz
-      )
+    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-do-complex-out.hs b/data/examples/declaration/value/function/arrow/proc-do-complex-out.hs
--- a/data/examples/declaration/value/function/arrow/proc-do-complex-out.hs
+++ b/data/examples/declaration/value/function/arrow/proc-do-complex-out.hs
@@ -19,10 +19,11 @@
           )
           ( b,
             d
-          ) -<
-          ( b + 1, -- Funnel into arrow
-            d * b
           )
+          -<
+            ( b + 1, -- Funnel into arrow
+              d * b
+            )
       if x `mod` y == 0 -- Basic condition
         then case e of -- Only left case is relevant
           Left
@@ -32,9 +33,10 @@
               let v =
                     u -- Actually never used
                       ^ 2
-               in ( returnA -<
-                      -- Just do the calculation
-                      (x + y * z)
+               in ( returnA
+                      -<
+                        -- Just do the calculation
+                        (x + y * z)
                   )
         else do
           let u = x -- Let bindings bind expressions, not commands
@@ -42,8 +44,9 @@
           i <- case u of
             0 -> (g . h -< u)
             n ->
-              ( ( h . g -<
-                    y -- First actual use of y
+              ( ( h . g
+                    -<
+                      y -- First actual use of y
                 )
               )
           returnA -< ()
@@ -51,8 +54,9 @@
           if i > 0
             then ma -< ()
             else returnA -< ()
-          returnA -<
-            ( i
-                + x
-                * y -- Just do the calculation
-            )
+          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
--- a/data/examples/declaration/value/function/arrow/proc-do-simple1-out.hs
+++ b/data/examples/declaration/value/function/arrow/proc-do-simple1-out.hs
@@ -13,5 +13,6 @@
 
 bazbar f = proc a -> do
   a <-
-    f -<
-      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
--- a/data/examples/declaration/value/function/arrow/proc-do-simple2-out.hs
+++ b/data/examples/declaration/value/function/arrow/proc-do-simple2-out.hs
@@ -11,10 +11,12 @@
   z <-
     h
       x
-      y -<
-      ( a,
-        b,
-        c
-      )
-  returnA -<
-    (x, y, z)
+      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
--- a/data/examples/declaration/value/function/arrow/proc-forms1-out.hs
+++ b/data/examples/declaration/value/function/arrow/proc-forms1-out.hs
@@ -7,13 +7,15 @@
     (|
       test
         ( h f
-            . h g -<
-            y x
-              . y z
+            . h g
+            -<
+              y x
+                . y z
         )
         ( h g
-            . h f -<
-            y z
-              . y x
+            . 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
--- a/data/examples/declaration/value/function/arrow/proc-forms2-out.hs
+++ b/data/examples/declaration/value/function/arrow/proc-forms2-out.hs
@@ -4,15 +4,19 @@
   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
+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)
+    (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)
+    ( (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
--- a/data/examples/declaration/value/function/arrow/proc-forms2.hs
+++ b/data/examples/declaration/value/function/arrow/proc-forms2.hs
@@ -4,16 +4,16 @@
   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
+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)
+    (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 f.h g)
+      -<  (y x).y z)
   |||
-    (h g  .  h f)
-      -<y z  .  (y x)
+    ((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
--- a/data/examples/declaration/value/function/arrow/proc-ifs-out.hs
+++ b/data/examples/declaration/value/function/arrow/proc-ifs-out.hs
@@ -6,8 +6,10 @@
   if f a
     then
       f
-        . g -<
-        a
+        . g
+        -<
+          a
     else
-      g -<
-        b
+      g
+        -<
+          b
diff --git a/data/examples/declaration/value/function/arrow/proc-parentheses-out.hs b/data/examples/declaration/value/function/arrow/proc-parentheses-out.hs
--- a/data/examples/declaration/value/function/arrow/proc-parentheses-out.hs
+++ b/data/examples/declaration/value/function/arrow/proc-parentheses-out.hs
@@ -6,13 +6,14 @@
   ( ( (f)
         ( g
         )
-    ) -<
-      ( ( ( ( ( ( g
-                    a
+    )
+      -<
+        ( ( ( ( ( ( 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
--- a/data/examples/declaration/value/function/arrow/recursive-procs-out.hs
+++ b/data/examples/declaration/value/function/arrow/recursive-procs-out.hs
@@ -3,17 +3,21 @@
 foo f g = proc (x, y) -> do
   rec a <- f y -< x
       b <-
-        g x -<
-          y
-  bar -<
-    ( a,
-      b
-    )
+        g x
+          -<
+            y
+  bar
+    -<
+      ( a,
+        b
+      )
   rec p <-
         f
-          p -<
-          a
+          p
+          -<
+            a
   rec q <-
         g
-          q -<
-          b
+          q
+          -<
+            b
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
--- a/data/examples/declaration/value/function/pattern/famous-cardano-pattern-out.hs
+++ b/data/examples/declaration/value/function/pattern/famous-cardano-pattern-out.hs
@@ -1,8 +1,8 @@
-( getNodeSettingsR :<|>
-    getNodeInfoR :<|>
-    getNextUpdateR :<|>
-    restartNodeR
-  ) :<|>
-  ( getUtxoR :<|>
-      getConfirmedProposalsR
-    ) = client nodeV1Api
+( 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
--- a/data/examples/declaration/value/function/pattern/multiline-case-pattern-out.hs
+++ b/data/examples/declaration/value/function/pattern/multiline-case-pattern-out.hs
@@ -10,6 +10,6 @@
     ] -> a + b
 
 g xs = case xs of
-  ( a :
-      bs
+  ( a
+      : bs
     ) -> a + b
diff --git a/data/examples/declaration/value/function/pattern/view-pattern-out.hs b/data/examples/declaration/value/function/pattern/view-pattern-out.hs
--- a/data/examples/declaration/value/function/pattern/view-pattern-out.hs
+++ b/data/examples/declaration/value/function/pattern/view-pattern-out.hs
@@ -13,6 +13,3 @@
         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
--- a/data/examples/declaration/value/function/pattern/view-pattern.hs
+++ b/data/examples/declaration/value/function/pattern/view-pattern.hs
@@ -10,6 +10,3 @@
 multiline (t -> Foo
                   bar
                   baz) = True
-
--- https://github.com/tweag/ormolu/issues/343
-foo = (f -> 4)
diff --git a/data/examples/import/qualified-post-out.hs b/data/examples/import/qualified-post-out.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/qualified-post-out.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE ImportQualifiedPost #-}
+
+import Data.Text qualified as T
+import Data.Text qualified (a, b, c)
+import Data.Text qualified hiding (a, b, c)
diff --git a/data/examples/import/qualified-post.hs b/data/examples/import/qualified-post.hs
new file mode 100644
--- /dev/null
+++ b/data/examples/import/qualified-post.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE ImportQualifiedPost #-}
+
+import qualified Data.Text as T
+import qualified Data.Text (a, c, b)
+import Data.Text qualified hiding (c, b, a)
diff --git a/data/examples/import/qualified-prelude-out.hs b/data/examples/import/qualified-prelude-out.hs
--- a/data/examples/import/qualified-prelude-out.hs
+++ b/data/examples/import/qualified-prelude-out.hs
@@ -1,4 +1,4 @@
 module P where
 
-import Prelude hiding ((.), id)
 import qualified Prelude
+import Prelude hiding ((.), id)
diff --git a/data/examples/other/multiline-forall-out.hs b/data/examples/other/multiline-forall-out.hs
--- a/data/examples/other/multiline-forall-out.hs
+++ b/data/examples/other/multiline-forall-out.hs
@@ -12,8 +12,7 @@
       )
       (x :: *)
       (y :: *).
-    D
-      (f x y)
+    D (f x y)
 
 data G where
   G ::
diff --git a/ormolu.cabal b/ormolu.cabal
--- a/ormolu.cabal
+++ b/ormolu.cabal
@@ -1,7 +1,7 @@
 name:                 ormolu
-version:              0.0.3.1
+version:              0.0.4.0
 cabal-version:        1.18
-tested-with:          GHC==8.6.5
+tested-with:          GHC==8.6.5, GHC==8.8.3, GHC==8.10.1
 license:              BSD3
 license-file:         LICENSE.md
 maintainer:           Mark Karpov <mark.karpov@tweag.io>
@@ -68,7 +68,7 @@
                     , containers     >= 0.5 && < 0.7
                     , dlist          >= 0.8 && < 0.9
                     , exceptions     >= 0.6 && < 0.11
-                    , ghc-lib-parser >= 8.8.1 && < 8.8.3
+                    , ghc-lib-parser >= 8.10 && < 8.11
                     , mtl            >= 2.0 && < 3.0
                     , syb            >= 0.7 && < 0.8
                     , text           >= 0.2 && < 1.3
@@ -116,7 +116,6 @@
                       -Wincomplete-record-updates
                       -Wincomplete-uni-patterns
                       -Wnoncanonical-monad-instances
-                      -Wnoncanonical-monadfail-instances
                       -- https://github.com/haskell/haddock/issues/1116
                       -Wno-missing-home-modules
   else
@@ -150,7 +149,7 @@
   main-is:            Main.hs
   hs-source-dirs:     app
   build-depends:      base           >= 4.12 && < 5.0
-                    , ghc-lib-parser >= 8.8.1 && < 8.8.3
+                    , ghc-lib-parser >= 8.10 && < 8.11
                     , gitrev         >= 1.3 && < 1.4
                     , optparse-applicative >= 0.14 && < 0.16
                     , ormolu
@@ -161,7 +160,6 @@
                       -Wincomplete-record-updates
                       -Wincomplete-uni-patterns
                       -Wnoncanonical-monad-instances
-                      -Wnoncanonical-monadfail-instances
   else
-    ghc-options:      -O2 -Wall
+    ghc-options:      -O2 -Wall -rtsopts
   default-language:   Haskell2010
diff --git a/src/GHC.hs b/src/GHC.hs
--- a/src/GHC.hs
+++ b/src/GHC.hs
@@ -6,16 +6,8 @@
 
 import ApiAnnotation as X
 import BasicTypes as X
-import HsBinds as X
-import HsDecls as X
-import HsDoc as X
-import HsExpr as X
-import HsExtension as X
-import HsImpExp as X
-import HsInstances as X ()
-import HsLit as X
-import HsPat as X
-import HsSyn as X
+import GHC.Hs as X
+import GHC.Hs.Instances as X ()
 import Module as X
 import RdrName as X
 import SrcLoc as X
diff --git a/src/GHC/DynFlags.hs b/src/GHC/DynFlags.hs
--- a/src/GHC/DynFlags.hs
+++ b/src/GHC/DynFlags.hs
@@ -1,5 +1,7 @@
 {-# OPTIONS_GHC -Wno-missing-fields #-}
 
+-- Modified from ghc-lib-api-ext.
+
 module GHC.DynFlags
   ( baseDynFlags,
   )
@@ -8,31 +10,40 @@
 import Config
 import DynFlags
 import Fingerprint
-import Platform
+import GHC.Platform
+import ToolSettings
 
--- | Taken from HLint.
 fakeSettings :: Settings
 fakeSettings =
   Settings
-    { sTargetPlatform = platform,
-      sPlatformConstants = platformConstants,
-      sProjectVersion = cProjectVersion,
-      sProgramName = "ghc",
-      sOpt_P_fingerprint = fingerprint0,
-      sPgm_F = ""
+    { sGhcNameVersion =
+        GhcNameVersion
+          { ghcNameVersion_programName = "ghc",
+            ghcNameVersion_projectVersion = cProjectVersion
+          },
+      sFileSettings = FileSettings {},
+      sTargetPlatform =
+        Platform
+          { platformWordSize = PW8,
+            platformMini =
+              PlatformMini
+                { platformMini_arch = ArchUnknown,
+                  platformMini_os = OSUnknown
+                },
+            platformUnregisterised = True
+          },
+      sPlatformMisc = PlatformMisc {},
+      sPlatformConstants =
+        PlatformConstants {pc_DYNAMIC_BY_DEFAULT = False, pc_WORD_SIZE = 8},
+      sToolSettings =
+        ToolSettings
+          { toolSettings_opt_P_fingerprint = fingerprint0,
+            toolSettings_pgm_F = ""
+          }
     }
-  where
-    platform =
-      Platform
-        { platformWordSize = 8,
-          platformOS = OSUnknown,
-          platformUnregisterised = True
-        }
-    platformConstants =
-      PlatformConstants {pc_DYNAMIC_BY_DEFAULT = False, pc_WORD_SIZE = 8}
 
-fakeLlvmConfig :: (LlvmTargets, LlvmPasses)
-fakeLlvmConfig = ([], [])
+fakeLlvmConfig :: LlvmConfig
+fakeLlvmConfig = LlvmConfig [] []
 
 baseDynFlags :: DynFlags
 baseDynFlags = defaultDynFlags fakeSettings fakeLlvmConfig
diff --git a/src/Ormolu/Config.hs b/src/Ormolu/Config.hs
--- a/src/Ormolu/Config.hs
+++ b/src/Ormolu/Config.hs
@@ -10,21 +10,20 @@
 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
-      }
+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'.
@@ -39,10 +38,9 @@
     }
 
 -- | A wrapper for dynamic options.
-newtype DynOption
-  = DynOption
-      { unDynOption :: String
-      }
+newtype DynOption = DynOption
+  { unDynOption :: String
+  }
   deriving (Eq, Ord, Show)
 
 -- | Convert 'DynOption' to @'GHC.Located' 'String'@.
diff --git a/src/Ormolu/Diff.hs b/src/Ormolu/Diff.hs
--- a/src/Ormolu/Diff.hs
+++ b/src/Ormolu/Diff.hs
@@ -8,7 +8,6 @@
   )
 where
 
-import BasicTypes (SourceText)
 import Data.ByteString (ByteString)
 import Data.Generics
 import Data.Text (Text)
@@ -71,6 +70,7 @@
                 `extQ` hsModuleEq
                 `extQ` sourceTextEq
                 `extQ` hsDocStringEq
+                `extQ` importDeclQualifiedStyleEq
                 `ext2Q` forLocated
             )
             x
@@ -88,6 +88,13 @@
             hs1 {hsmodImports = sortImports (hsmodImports hs1)}
     sourceTextEq :: SourceText -> GenericQ Diff
     sourceTextEq _ _ = Same
+    importDeclQualifiedStyleEq :: ImportDeclQualifiedStyle -> GenericQ Diff
+    importDeclQualifiedStyleEq d0 d1' =
+      case (d0, cast d1' :: Maybe ImportDeclQualifiedStyle) of
+        (x, Just x') | x == x' -> Same
+        (QualifiedPre, Just QualifiedPost) -> Same
+        (QualifiedPost, Just QualifiedPre) -> Same
+        _ -> Different []
     hsDocStringEq :: HsDocString -> GenericQ Diff
     hsDocStringEq str0 str1' =
       case cast str1' :: Maybe HsDocString of
diff --git a/src/Ormolu/Imports.hs b/src/Ormolu/Imports.hs
--- a/src/Ormolu/Imports.hs
+++ b/src/Ormolu/Imports.hs
@@ -13,8 +13,8 @@
 import Data.Generics (gcompare)
 import Data.List (sortBy)
 import GHC hiding (GhcPs, IE)
-import HsExtension
-import HsImpExp (IE (..))
+import GHC.Hs.Extension
+import GHC.Hs.ImpExp (IE (..))
 import Ormolu.Utils (notImplemented)
 
 -- | Sort imports by module name. This also sorts explicit import lists for
@@ -29,7 +29,7 @@
           { ideclHiding = second (fmap sortLies) <$> ideclHiding,
             ..
           }
-      XImportDecl {} -> notImplemented "XImportDecl"
+      XImportDecl x -> noExtCon x
 
 -- | Compare two @'LImportDecl' 'GhcPs'@ things.
 compareIdecl :: LImportDecl GhcPs -> LImportDecl GhcPs -> Ordering
@@ -51,8 +51,8 @@
 -- | 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
+  IEThingWith NoExtField x w xs fl ->
+    IEThingWith NoExtField x w (sortBy (compareIewn `on` unLoc) xs) fl
   other -> other
 
 -- | Compare two located imports or exports.
@@ -62,15 +62,15 @@
 -- | 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"
+  IEVar NoExtField x -> unLoc x
+  IEThingAbs NoExtField x -> unLoc x
+  IEThingAll NoExtField x -> unLoc x
+  IEThingWith NoExtField x _ _ _ -> unLoc x
+  IEModuleContents NoExtField _ -> notImplemented "IEModuleContents"
+  IEGroup NoExtField _ _ -> notImplemented "IEGroup"
+  IEDoc NoExtField _ -> notImplemented "IEDoc"
+  IEDocNamed NoExtField _ -> notImplemented "IEDocNamed"
+  XIE x -> noExtCon x
 
 -- | Compare two @'IEWrapppedName' 'RdrName'@ things.
 compareIewn :: IEWrappedName RdrName -> IEWrappedName RdrName -> Ordering
diff --git a/src/Ormolu/Parser.hs b/src/Ormolu/Parser.hs
--- a/src/Ormolu/Parser.hs
+++ b/src/Ormolu/Parser.hs
@@ -9,14 +9,17 @@
   )
 where
 
+import Bag (bagToList)
 import qualified CmdLineParser as GHC
 import Control.Exception
 import Control.Monad
 import Control.Monad.IO.Class
-import Data.List ((\\), foldl', isPrefixOf)
+import Data.List ((\\), foldl', isPrefixOf, sortOn)
 import qualified Data.List.NonEmpty as NE
 import Data.Maybe (catMaybes)
+import Data.Ord (Down (Down))
 import DynFlags as GHC
+import ErrUtils (Severity (..), errMsgSeverity, errMsgSpan)
 import qualified FastString as GHC
 import GHC hiding (IE, UnicodeSyntax)
 import GHC.DynFlags (baseDynFlags)
@@ -29,7 +32,6 @@
 import Ormolu.Parser.Anns
 import Ormolu.Parser.CommentStream
 import Ormolu.Parser.Result
-import qualified Outputable as GHC
 import qualified Panic as GHC
 import qualified Parser as GHC
 import qualified StringBuffer as GHC
@@ -73,20 +75,36 @@
           || any
             (("RecordDotPreprocessor" ==) . moduleNameString)
             (pluginModNames dynFlags)
+      pStateErrors = \pstate ->
+        let errs = bagToList $ GHC.getErrorMessages pstate dynFlags
+         in case sortOn (Down . SeverityOrd . errMsgSeverity) errs of
+              [] -> Nothing
+              err : _ -> Just (errMsgSpan err, show err) -- Show instance returns a short error message
       r = case runParser GHC.parseModule dynFlags path input of
-        GHC.PFailed _ ss m ->
-          Left (ss, GHC.showSDoc dynFlags m)
+        GHC.PFailed pstate ->
+          case pStateErrors pstate of
+            Just err -> Left err
+            Nothing -> error "invariant violation: PFailed does not have an error"
         GHC.POk pstate pmod ->
-          let (comments, exts, shebangs) = mkCommentStream extraComments pstate
-           in Right
-                ParseResult
-                  { prParsedSource = pmod,
-                    prAnns = mkAnns pstate,
-                    prCommentStream = comments,
-                    prExtensions = exts,
-                    prShebangs = shebangs,
-                    prUseRecordDot = useRecordDot
-                  }
+          case pStateErrors pstate of
+            -- Some parse errors (pattern/arrow syntax in expr context)
+            -- do not cause a parse error, but they are replaced with "_"
+            -- by the parser and the modified AST is propagated to the
+            -- later stages; but we fail in those cases.
+            Just err -> Left err
+            Nothing ->
+              let (comments, exts, shebangs) = mkCommentStream extraComments pstate
+               in Right
+                    ParseResult
+                      { prParsedSource = pmod,
+                        prAnns = mkAnns pstate,
+                        prCommentStream = comments,
+                        prExtensions = exts,
+                        prShebangs = shebangs,
+                        prUseRecordDot = useRecordDot,
+                        prImportQualifiedPost =
+                          GHC.xopt ImportQualifiedPost dynFlags
+                      }
   return (warnings, r)
 
 -- | Extensions that are not enabled automatically and should be activated
@@ -108,9 +126,11 @@
     MonadComprehensions,
     UnboxedSums,
     UnicodeSyntax, -- gives special meanings to operators like (→)
-    TemplateHaskellQuotes -- enables TH subset of quasi-quotes, this
+    TemplateHaskellQuotes, -- enables TH subset of quasi-quotes, this
     -- apparently interferes with QuasiQuotes in
     -- weird ways
+    ImportQualifiedPost -- affects how Ormolu renders imports, so the
+    -- decision of enabling this style is left to the user
   ]
 
 ----------------------------------------------------------------------------
@@ -223,3 +243,25 @@
         reportErr
         (GHC.handleSourceError reportErr act)
     reportErr e = return $ Left (show e)
+
+----------------------------------------------------------------------------
+-- Even more helpers
+
+-- Wrap GHC's ErrUtils.Severity to add Ord instance
+newtype SeverityOrd = SeverityOrd Severity
+
+instance Eq SeverityOrd where
+  s1 == s2 = compare s1 s2 == EQ
+
+instance Ord SeverityOrd where
+  compare (SeverityOrd s1) (SeverityOrd s2) =
+    compare (f s1) (f s2)
+    where
+      f :: Severity -> Int
+      f SevOutput = 1
+      f SevFatal = 2
+      f SevInteractive = 3
+      f SevDump = 4
+      f SevInfo = 5
+      f SevWarning = 6
+      f SevError = 7
diff --git a/src/Ormolu/Parser/Pragma.hs b/src/Ormolu/Parser/Pragma.hs
--- a/src/Ormolu/Parser/Pragma.hs
+++ b/src/Ormolu/Parser/Pragma.hs
@@ -10,7 +10,7 @@
 
 import Control.Monad
 import Data.Char (isSpace, toLower)
-import Data.List
+import qualified Data.List as L
 import qualified EnumSet as ES
 import FastString (mkFastString, unpackFS)
 import qualified Lexer as L
@@ -35,8 +35,8 @@
   String ->
   Maybe Pragma
 parsePragma input = do
-  inputNoPrefix <- stripPrefix "{-#" input
-  guard ("#-}" `isSuffixOf` input)
+  inputNoPrefix <- L.stripPrefix "{-#" input
+  guard ("#-}" `L.isSuffixOf` input)
   let contents = take (length inputNoPrefix - 3) inputNoPrefix
       (pragmaName, cs) = (break isSpace . dropWhile isSpace) contents
   case toLower <$> pragmaName of
@@ -46,7 +46,7 @@
     _ -> Nothing
   where
     trimSpaces :: String -> String
-    trimSpaces = dropWhileEnd isSpace . dropWhile isSpace
+    trimSpaces = L.dropWhileEnd isSpace . dropWhile isSpace
 
 -- | Assuming the input consists of a series of tokens from a language
 -- pragma, return the set of enabled extensions.
diff --git a/src/Ormolu/Parser/Result.hs b/src/Ormolu/Parser/Result.hs
--- a/src/Ormolu/Parser/Result.hs
+++ b/src/Ormolu/Parser/Result.hs
@@ -13,21 +13,22 @@
 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],
-        -- | Shebangs found in the input
-        prShebangs :: [Located String],
-        -- | Whether or not record dot syntax is enabled
-        prUseRecordDot :: Bool
-      }
+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],
+    -- | Shebangs found in the input
+    prShebangs :: [Located String],
+    -- | Whether or not record dot syntax is enabled
+    prUseRecordDot :: Bool,
+    -- | Whether or not ImportQualifiedPost is enabled
+    prImportQualifiedPost :: Bool
+  }
 
 -- | Pretty-print a 'ParseResult'.
 prettyPrintParseResult :: ParseResult -> String
diff --git a/src/Ormolu/Printer.hs b/src/Ormolu/Printer.hs
--- a/src/Ormolu/Printer.hs
+++ b/src/Ormolu/Printer.hs
@@ -20,7 +20,12 @@
   Text
 printModule ParseResult {..} =
   runR
-    (p_hsModule prShebangs prExtensions prParsedSource)
+    ( p_hsModule
+        prShebangs
+        prExtensions
+        prImportQualifiedPost
+        prParsedSource
+    )
     (mkSpanStream prParsedSource)
     prCommentStream
     prAnns
diff --git a/src/Ormolu/Printer/Combinators.hs b/src/Ormolu/Printer/Combinators.hs
--- a/src/Ormolu/Printer/Combinators.hs
+++ b/src/Ormolu/Printer/Combinators.hs
@@ -23,7 +23,6 @@
     inci,
     located,
     located',
-    locatedPat,
     switchLayout,
     Layout (..),
     vlayout,
@@ -64,7 +63,6 @@
 import Data.Data (Data)
 import Data.List (intersperse)
 import Data.Text (Text)
-import GHC (Pat (XPat), XXPat)
 import Ormolu.Printer.Comments
 import Ormolu.Printer.Internal
 import Ormolu.Utils (isModule)
@@ -110,28 +108,6 @@
   Located a ->
   R ()
 located' = flip located
-
--- | A version of 'located' that works on 'Pat'.
---
--- Starting from GHC 8.8, @'LPat' == 'Pat'@. Located 'Pat's are always
--- constructed with the 'XPat' constructor, containing a @'Located' 'Pat'@.
---
--- Most of the time, we can just use 'p_pat' directly, because it handles
--- located 'Pat's. However, sometimes we want to use the location to render
--- something other than the given 'Pat'.
---
--- If given 'Pat' does not contain a location, we error out.
---
--- This should become unnecessary if
--- <https://gitlab.haskell.org/ghc/ghc/issues/17330> is ever fixed.
-locatedPat ::
-  (Data (Pat pass), XXPat pass ~ Located (Pat pass)) =>
-  Pat pass ->
-  (Pat pass -> R ()) ->
-  R ()
-locatedPat p f = case p of
-  XPat pat -> located pat f
-  _ -> error "locatedPat: Pat does not contain a location"
 
 -- | 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
diff --git a/src/Ormolu/Printer/Internal.hs b/src/Ormolu/Printer/Internal.hs
--- a/src/Ormolu/Printer/Internal.hs
+++ b/src/Ormolu/Printer/Internal.hs
@@ -73,45 +73,43 @@
 
 -- | 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,
-        -- | Whether the last expression in the layout can use braces
-        rcCanUseBraces :: Bool,
-        -- | Whether the source could have used the record dot preprocessor
-        rcUseRecDot :: Bool
-      }
+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,
+    -- | Whether the last expression in the layout can use braces
+    rcCanUseBraces :: Bool,
+    -- | Whether the source could have used the record dot preprocessor
+    rcUseRecDot :: 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))
-      }
+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
diff --git a/src/Ormolu/Printer/Meat/Common.hs b/src/Ormolu/Printer/Meat/Common.hs
--- a/src/Ormolu/Printer/Meat/Common.hs
+++ b/src/Ormolu/Printer/Meat/Common.hs
@@ -24,7 +24,6 @@
 import OccName (OccName (..))
 import Ormolu.Printer.Combinators
 import Ormolu.Utils
-import RdrName (RdrName (..))
 
 -- | Data and type family style.
 data FamilyStyle
diff --git a/src/Ormolu/Printer/Meat/Declaration.hs b/src/Ormolu/Printer/Meat/Declaration.hs
--- a/src/Ormolu/Printer/Meat/Declaration.hs
+++ b/src/Ormolu/Printer/Meat/Declaration.hs
@@ -34,7 +34,6 @@
 import Ormolu.Printer.Meat.Declaration.Warning
 import Ormolu.Printer.Meat.Type
 import Ormolu.Utils
-import RdrName (rdrNameOcc)
 
 data UserGrouping
   = -- | Always put newlines where we think they should be
@@ -110,29 +109,30 @@
 
 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 ->
+  TyClD NoExtField x -> p_tyClDecl style x
+  ValD NoExtField x -> p_valDecl x
+  SigD NoExtField x -> p_sigDecl x
+  InstD NoExtField x -> p_instDecl style x
+  DerivD NoExtField x -> p_derivDecl x
+  DefD NoExtField x -> p_defaultDecl x
+  ForD NoExtField x -> p_foreignDecl x
+  WarningD NoExtField x -> p_warnDecls x
+  AnnD NoExtField x -> p_annDecl x
+  RuleD NoExtField x -> p_ruleDecls x
+  SpliceD NoExtField x -> p_spliceDecl x
+  DocD NoExtField 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"
+  RoleAnnotD NoExtField x -> p_roleAnnot x
+  KindSigD NoExtField s -> p_standaloneKindSig s
+  XHsDecl x -> noExtCon x
 
 p_tyClDecl :: FamilyStyle -> TyClDecl GhcPs -> R ()
 p_tyClDecl style = \case
-  FamDecl NoExt x -> p_famDecl style x
+  FamDecl NoExtField x -> p_famDecl style x
   SynDecl {..} -> p_synDecl tcdLName tcdFixity tcdTyVars tcdRhs
   DataDecl {..} ->
     p_dataDecl
@@ -153,19 +153,19 @@
       tcdATs
       tcdATDefs
       tcdDocs
-  XTyClDecl {} -> notImplemented "XTyClDecl"
+  XTyClDecl x -> noExtCon x
 
 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"
+  ClsInstD NoExtField x -> p_clsInstDecl x
+  TyFamInstD NoExtField x -> p_tyFamInstDecl style x
+  DataFamInstD NoExtField x -> p_dataFamInstDecl style x
+  XInstDecl x -> noExtCon x
 
 p_derivDecl :: DerivDecl GhcPs -> R ()
 p_derivDecl = \case
-  d@DerivDecl {..} -> p_standaloneDerivDecl d
-  XDerivDecl _ -> notImplemented "XDerivDecl standalone deriving"
+  d@DerivDecl {} -> p_standaloneDerivDecl d
+  XDerivDecl x -> noExtCon x
 
 -- | Determine if these declarations should be grouped together.
 groupedDecls ::
@@ -186,6 +186,9 @@
 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 (KindSignature n) (DataDeclaration n') = n == n'
+groupedDecls (KindSignature n) (ClassDeclaration n') = n == n'
+groupedDecls (KindSignature n) (FamilyDeclaration n') = n == n'
 -- This looks only at Haddocks, normal comments are handled elsewhere
 groupedDecls DocNext _ = True
 groupedDecls _ DocPrev = True
@@ -223,15 +226,21 @@
   AnnTypePragma,
   AnnValuePragma,
   Pattern,
-  DataDeclaration ::
+  DataDeclaration,
+  ClassDeclaration,
+  KindSignature,
+  FamilyDeclaration ::
     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) _ _ _)
+pattern InlinePragma n <- SigD NoExtField (InlineSig NoExtField (L _ n) _)
+pattern SpecializePragma n <- SigD NoExtField (SpecSig NoExtField (L _ n) _ _)
+pattern SCCPragma n <- SigD NoExtField (SCCFunSig NoExtField _ (L _ n) _)
+pattern AnnTypePragma n <- AnnD NoExtField (HsAnnotation NoExtField _ (TypeAnnProvenance (L _ n)) _)
+pattern AnnValuePragma n <- AnnD NoExtField (HsAnnotation NoExtField _ (ValueAnnProvenance (L _ n)) _)
+pattern Pattern n <- ValD NoExtField (PatSynBind NoExtField (PSB _ (L _ n) _ _ _))
+pattern DataDeclaration n <- TyClD NoExtField (DataDecl NoExtField (L _ n) _ _ _)
+pattern ClassDeclaration n <- TyClD NoExtField (ClassDecl NoExtField _ (L _ n) _ _ _ _ _ _ _ _)
+pattern KindSignature n <- KindSigD NoExtField (StandaloneKindSig NoExtField (L _ n) _)
+pattern FamilyDeclaration n <- TyClD NoExtField (FamDecl NoExtField (FamilyDecl NoExtField _ (L _ n) _ _ _ _))
 
 -- Declarations which can refer to multiple names
 
@@ -249,51 +258,51 @@
 pattern WarningPragma n <- (warnSigRdrNames -> Just n)
 
 pattern DocNext, DocPrev :: HsDecl GhcPs
-pattern DocNext <- (DocD NoExt (DocCommentNext _))
-pattern DocPrev <- (DocD NoExt (DocCommentPrev _))
+pattern DocNext <- (DocD NoExtField (DocCommentNext _))
+pattern DocPrev <- (DocD NoExtField (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 (SigD NoExtField (TypeSig NoExtField ns _)) = Just $ map unLoc ns
+sigRdrNames (SigD NoExtField (ClassOpSig NoExtField _ ns _)) = Just $ map unLoc ns
+sigRdrNames (SigD NoExtField (PatSynSig NoExtField ns _)) = Just $ map unLoc ns
 sigRdrNames _ = Nothing
 
 defSigRdrNames :: HsDecl GhcPs -> Maybe [RdrName]
-defSigRdrNames (SigD NoExt (ClassOpSig NoExt True ns _)) = Just $ map unLoc ns
+defSigRdrNames (SigD NoExtField (ClassOpSig NoExtField True ns _)) = Just $ map unLoc ns
 defSigRdrNames _ = Nothing
 
 funRdrNames :: HsDecl GhcPs -> Maybe [RdrName]
-funRdrNames (ValD NoExt (FunBind NoExt (L _ n) _ _ _)) = Just [n]
-funRdrNames (ValD NoExt (PatBind NoExt n _ _)) = Just $ patBindNames n
+funRdrNames (ValD NoExtField (FunBind NoExtField (L _ n) _ _ _)) = Just [n]
+funRdrNames (ValD NoExtField (PatBind NoExtField (L _ n) _ _)) = Just $ patBindNames n
 funRdrNames _ = Nothing
 
 patSigRdrNames :: HsDecl GhcPs -> Maybe [RdrName]
-patSigRdrNames (SigD NoExt (PatSynSig NoExt ns _)) = Just $ map unLoc ns
+patSigRdrNames (SigD NoExtField (PatSynSig NoExtField 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 (WarningD NoExtField (Warnings NoExtField _ ws)) = Just $ flip concatMap ws $ \case
+  L _ (Warning NoExtField ns _) -> map unLoc ns
+  L _ (XWarnDecl x) -> noExtCon x
 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 p) = patBindNames p
-patBindNames (BangPat NoExt p) = patBindNames p
-patBindNames (ParPat NoExt p) = patBindNames p
-patBindNames (ListPat NoExt ps) = concatMap (patBindNames . unLoc) ps
-patBindNames (AsPat NoExt (L _ n) p) = n : patBindNames p
-patBindNames (SumPat NoExt p _ _) = patBindNames p
-patBindNames (ViewPat NoExt _ p) = patBindNames p
-patBindNames (SplicePat NoExt _) = []
-patBindNames (LitPat NoExt _) = []
-patBindNames (SigPat _ p _) = patBindNames p
-patBindNames (NPat NoExt _ _ _) = []
-patBindNames (NPlusKPat NoExt (L _ n) _ _ _ _) = [n]
+patBindNames (TuplePat NoExtField ps _) = concatMap (patBindNames . unLoc) ps
+patBindNames (VarPat NoExtField (L _ n)) = [n]
+patBindNames (WildPat NoExtField) = []
+patBindNames (LazyPat NoExtField (L _ p)) = patBindNames p
+patBindNames (BangPat NoExtField (L _ p)) = patBindNames p
+patBindNames (ParPat NoExtField (L _ p)) = patBindNames p
+patBindNames (ListPat NoExtField ps) = concatMap (patBindNames . unLoc) ps
+patBindNames (AsPat NoExtField (L _ n) (L _ p)) = n : patBindNames p
+patBindNames (SumPat NoExtField (L _ p) _ _) = patBindNames p
+patBindNames (ViewPat NoExtField _ (L _ p)) = patBindNames p
+patBindNames (SplicePat NoExtField _) = []
+patBindNames (LitPat NoExtField _) = []
+patBindNames (SigPat _ (L _ p) _) = patBindNames p
+patBindNames (NPat NoExtField _ _ _) = []
+patBindNames (NPlusKPat NoExtField (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 p) = patBindNames (unLoc p)
+patBindNames (CoPat NoExtField _ p _) = patBindNames p
+patBindNames (XPat x) = noExtCon x
diff --git a/src/Ormolu/Printer/Meat/Declaration/Annotation.hs b/src/Ormolu/Printer/Meat/Declaration/Annotation.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Annotation.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Annotation.hs
@@ -10,15 +10,14 @@
 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
+  HsAnnotation NoExtField _ annProv expr -> pragma "ANN" . inci $ do
     p_annProv annProv
     breakpoint
     located expr p_hsExpr
-  XAnnDecl {} -> notImplemented "XAnnDecl"
+  XAnnDecl x -> noExtCon x
 
 p_annProv :: AnnProvenance (IdP GhcPs) -> R ()
 p_annProv = \case
diff --git a/src/Ormolu/Printer/Meat/Declaration/Class.hs b/src/Ormolu/Printer/Meat/Declaration/Class.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Class.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Class.hs
@@ -18,8 +18,6 @@
 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 ->
@@ -30,7 +28,7 @@
   [LSig GhcPs] ->
   LHsBinds GhcPs ->
   [LFamilyDecl GhcPs] ->
-  [LTyFamDefltEqn GhcPs] ->
+  [LTyFamDefltDecl GhcPs] ->
   [LDocDecl] ->
   R ()
 p_classDecl ctx name HsQTvs {..} fixity fdeps csigs cdefs cats catdefs cdocs = do
@@ -38,6 +36,20 @@
       signatureSpans = getLoc name : variableSpans
       dependencySpans = getLoc <$> fdeps
       combinedSpans = getLoc ctx : (signatureSpans ++ dependencySpans)
+      -- GHC's AST does not necessarily store each kind of element in source
+      -- location order. This happens because different declarations are stored
+      -- in different lists. Consequently, to get all the declarations in proper
+      -- order, they need to be manually sorted.
+      sigs = (getLoc &&& fmap (SigD NoExtField)) <$> csigs
+      vals = (getLoc &&& fmap (ValD NoExtField)) <$> toList cdefs
+      tyFams = (getLoc &&& fmap (TyClD NoExtField . FamDecl NoExtField)) <$> cats
+      docs = (getLoc &&& fmap (DocD NoExtField)) <$> cdocs
+      tyFamDefs =
+        ( getLoc &&& fmap (InstD NoExtField . TyFamInstD NoExtField)
+        )
+          <$> catdefs
+      allDecls =
+        snd <$> sortOn fst (sigs <> vals <> tyFams <> tyFamDefs <> docs)
   txt "class"
   switchLayout combinedSpans $ do
     breakpoint
@@ -50,26 +62,13 @@
           (p_rdrName name)
           (located' p_hsTyVarBndr <$> hsq_explicit)
       inci (p_classFundeps fdeps)
-  -- GHC's AST does not necessarily store each kind of element in source
-  -- location order. This happens because different declarations are stored
-  -- in different lists. Consequently, to get all the declarations in proper
-  -- order, they need to be manually sorted.
-  let sigs = (getLoc &&& fmap (SigD NoExt)) <$> 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 <$> sortOn fst (sigs <> vals <> tyFams <> tyFamDefs <> docs)
+      unless (null allDecls) $ do
+        breakpoint
+        txt "where"
   unless (null allDecls) $ do
-    space
-    txt "where"
     breakpoint -- Ensure whitespace is added after where clause.
     inci (p_hsDeclsRespectGrouping Associated allDecls)
-p_classDecl _ _ XLHsQTyVars {} _ _ _ _ _ _ _ = notImplemented "XLHsQTyVars"
+p_classDecl _ _ (XLHsQTyVars c) _ _ _ _ _ _ _ = noExtCon c
 
 p_classContext :: LHsContext GhcPs -> R ()
 p_classContext ctx = unless (null (unLoc ctx)) $ do
@@ -95,13 +94,6 @@
 
 ----------------------------------------------------------------------------
 -- Helpers
-
-defltEqnToInstDecl :: TyFamDefltEqn GhcPs -> TyFamInstDecl GhcPs
-defltEqnToInstDecl FamEqn {..} = TyFamInstDecl {..}
-  where
-    eqn = FamEqn {feqn_pats = map HsValArg (tyVarsToTypes feqn_pats), ..}
-    tfid_eqn = HsIB {hsib_ext = NoExt, hsib_body = eqn}
-defltEqnToInstDecl XFamEqn {} = notImplemented "XFamEqn"
 
 isInfix :: LexicalFixity -> Bool
 isInfix = \case
diff --git a/src/Ormolu/Printer/Meat/Declaration/Data.hs b/src/Ormolu/Printer/Meat/Declaration/Data.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Data.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Data.hs
@@ -15,8 +15,6 @@
 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
@@ -37,7 +35,8 @@
   txt $ case style of
     Associated -> mempty
     Free -> " instance"
-  switchLayout (getLoc name : fmap getLoc tpats) $ do
+  let constructorSpans = getLoc name : fmap getLoc tpats
+  switchLayout constructorSpans $ do
     breakpoint
     inci $
       p_infixDefHelper
@@ -55,29 +54,40 @@
   let gadt = isJust dd_kindSig || any (isGadt . unLoc) dd_cons
   unless (null dd_cons) $
     if gadt
-      then do
-        space
-        txt "where"
+      then inci $ do
+        switchLayout constructorSpans $ do
+          breakpoint
+          txt "where"
         breakpoint
-        inci $ sepSemi (located' p_conDecl) dd_cons
+        sepSemi (located' (p_conDecl False)) dd_cons
       else switchLayout (getLoc name : (getLoc <$> dd_cons))
         $ inci
         $ do
-          breakpoint
+          let singleConstRec = isSingleConstRec dd_cons
+          if singleConstRec
+            then space
+            else breakpoint
           txt "="
           space
           let s =
                 vlayout
                   (space >> txt "|" >> space)
                   (newline >> txt "|" >> space)
-          sep s (sitcc . located' p_conDecl) dd_cons
+              sitcc' =
+                if singleConstRec
+                  then id
+                  else sitcc
+          sep s (sitcc' . located' (p_conDecl singleConstRec)) dd_cons
   unless (null $ unLoc dd_derivs) breakpoint
   inci . located dd_derivs $ \xs ->
     sep newline (located' p_hsDerivingClause) xs
-p_dataDecl _ _ _ _ (XHsDataDefn NoExt) = notImplemented "XHsDataDefn"
+p_dataDecl _ _ _ _ (XHsDataDefn x) = noExtCon x
 
-p_conDecl :: ConDecl GhcPs -> R ()
-p_conDecl = \case
+p_conDecl ::
+  Bool ->
+  ConDecl GhcPs ->
+  R ()
+p_conDecl singleConstRec = \case
   ConDeclGADT {..} -> do
     mapM_ (p_hsDocString Pipe True) con_doc
     let conDeclSpn =
@@ -104,7 +114,7 @@
                 else breakpoint
         interArgBreak
         when (unLoc con_forall) $ do
-          p_forallBndrs p_hsTyVarBndr (hsq_explicit con_qvars)
+          p_forallBndrs ForallInvis p_hsTyVarBndr (hsq_explicit con_qvars)
           interArgBreak
         forM_ con_mb_cxt p_lhsContext
         case con_args of
@@ -124,18 +134,19 @@
         p_hsType (unLoc con_res_ty)
   ConDeclH98 {..} -> do
     mapM_ (p_hsDocString Pipe True) con_doc
-    let conDeclSpn =
-          [getLoc con_name]
-            <> [getLoc con_forall]
+    let conDeclWithContextSpn =
+          [getLoc con_forall]
             <> fmap getLoc con_ex_tvs
             <> maybeToList (fmap getLoc con_mb_cxt)
-            <> conArgsSpans con_args
-    switchLayout conDeclSpn $ do
+            <> conDeclSpn
+        conDeclSpn =
+          getLoc con_name : conArgsSpans con_args
+    switchLayout conDeclWithContextSpn $ do
       when (unLoc con_forall) $ do
-        p_forallBndrs p_hsTyVarBndr con_ex_tvs
+        p_forallBndrs ForallInvis p_hsTyVarBndr con_ex_tvs
         breakpoint
       forM_ con_mb_cxt p_lhsContext
-      case con_args of
+      switchLayout conDeclSpn $ case con_args of
         PrefixCon xs -> do
           p_rdrName con_name
           unless (null xs) breakpoint
@@ -143,7 +154,11 @@
         RecCon l -> do
           p_rdrName con_name
           breakpoint
-          inci $ located l p_conDeclFields
+          let inci' =
+                if singleConstRec
+                  then id
+                  else inci
+          inci' (located l p_conDeclFields)
         InfixCon x y -> do
           located x p_hsType
           breakpoint
@@ -151,7 +166,7 @@
             p_rdrName con_name
             space
             located y p_hsType
-  XConDecl NoExt -> notImplemented "XConDecl"
+  XConDecl x -> noExtCon x
 
 conArgsSpans :: HsConDeclDetails GhcPs -> [SrcSpan]
 conArgsSpans = \case
@@ -165,7 +180,7 @@
 conTyVarsSpans :: LHsQTyVars GhcPs -> [SrcSpan]
 conTyVarsSpans = \case
   HsQTvs {..} -> getLoc <$> hsq_explicit
-  XLHsQTyVars NoExt -> []
+  XLHsQTyVars x -> noExtCon x
 
 p_lhsContext ::
   LHsContext GhcPs ->
@@ -223,9 +238,9 @@
           txt "via"
           space
           located hsib_body p_hsType
-      ViaStrategy (XHsImplicitBndrs NoExt) ->
-        notImplemented "XHsImplicitBndrs"
-p_hsDerivingClause (XHsDerivingClause NoExt) = notImplemented "XHsDerivingClause"
+      ViaStrategy (XHsImplicitBndrs x) ->
+        noExtCon x
+p_hsDerivingClause (XHsDerivingClause x) = noExtCon x
 
 ----------------------------------------------------------------------------
 -- Helpers
@@ -234,3 +249,10 @@
 isInfix = \case
   Infix -> True
   Prefix -> False
+
+isSingleConstRec :: [LConDecl GhcPs] -> Bool
+isSingleConstRec [(L _ ConDeclH98 {..})] =
+  case con_args of
+    RecCon _ -> True
+    _ -> False
+isSingleConstRec _ = False
diff --git a/src/Ormolu/Printer/Meat/Declaration/Default.hs b/src/Ormolu/Printer/Meat/Declaration/Default.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Default.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Default.hs
@@ -9,13 +9,12 @@
 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
+  DefaultDecl NoExtField ts -> do
     txt "default"
     breakpoint
     inci . parens N . sitcc $
       sep (comma >> breakpoint) (sitcc . located' p_hsType) ts
-  XDefaultDecl {} -> notImplemented "XDefaultDecl"
+  XDefaultDecl x -> noExtCon x
diff --git a/src/Ormolu/Printer/Meat/Declaration/Foreign.hs b/src/Ormolu/Printer/Meat/Declaration/Foreign.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Foreign.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Foreign.hs
@@ -15,7 +15,6 @@
 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
@@ -25,7 +24,7 @@
   fd@ForeignExport {fd_fe} -> do
     p_foreignExport fd_fe
     p_foreignTypeSig fd
-  XForeignDecl {} -> notImplemented "XForeignDecl"
+  XForeignDecl x -> noExtCon x
 
 -- | Printer for the last part of an import\/export, which is function name
 -- and type signature.
@@ -39,7 +38,7 @@
       ]
     $ do
       p_rdrName (fd_name fd)
-      p_typeAscription (HsWC NoExt (fd_sig_ty fd))
+      p_typeAscription (HsWC NoExtField (fd_sig_ty fd))
 
 -- | Printer for 'ForeignImport'.
 --
diff --git a/src/Ormolu/Printer/Meat/Declaration/Instance.hs b/src/Ormolu/Printer/Meat/Declaration/Instance.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Instance.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Instance.hs
@@ -56,8 +56,8 @@
         inci (located hsib_body p_hsType)
         breakpoint
         instTypes True
-      ViaStrategy (XHsImplicitBndrs NoExt) ->
-        notImplemented "XHsImplicitBndrs"
+      ViaStrategy (XHsImplicitBndrs x) ->
+        noExtCon x
 p_standaloneDerivDecl (XDerivDecl _) = notImplemented "XDerivDecl"
 
 p_clsInstDecl :: ClsInstDecl GhcPs -> R ()
@@ -70,14 +70,14 @@
         -- 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
+        let sigs = (getLoc &&& fmap (SigD NoExtField)) <$> cid_sigs
+            vals = (getLoc &&& fmap (ValD NoExtField)) <$> toList cid_binds
             tyFamInsts =
-              ( getLoc &&& fmap (InstD NoExt . TyFamInstD NoExt)
+              ( getLoc &&& fmap (InstD NoExtField . TyFamInstD NoExtField)
               )
                 <$> cid_tyfam_insts
             dataFamInsts =
-              ( getLoc &&& fmap (InstD NoExt . DataFamInstD NoExt)
+              ( getLoc &&& fmap (InstD NoExtField . DataFamInstD NoExtField)
               )
                 <$> cid_datafam_insts
             allDecls =
@@ -96,8 +96,8 @@
             -- Ensure whitespace is added after where clause.
             breakpoint
             dontUseBraces $ p_hsDeclsRespectGrouping Associated allDecls
-      XHsImplicitBndrs NoExt -> notImplemented "XHsImplicitBndrs"
-  XClsInstDecl NoExt -> notImplemented "XClsInstDecl"
+      XHsImplicitBndrs x -> noExtCon x
+  XClsInstDecl x -> noExtCon x
 
 p_tyFamInstDecl :: FamilyStyle -> TyFamInstDecl GhcPs -> R ()
 p_tyFamInstDecl style = \case
diff --git a/src/Ormolu/Printer/Meat/Declaration/RoleAnnotation.hs b/src/Ormolu/Printer/Meat/Declaration/RoleAnnotation.hs
--- a/src/Ormolu/Printer/Meat/Declaration/RoleAnnotation.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/RoleAnnotation.hs
@@ -12,14 +12,11 @@
 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"
+  RoleAnnotDecl NoExtField l_name anns -> p_roleAnnot' l_name anns
+  XRoleAnnotDecl x -> noExtCon x
 
 p_roleAnnot' :: Located RdrName -> [Located (Maybe Role)] -> R ()
 p_roleAnnot' l_name anns = do
diff --git a/src/Ormolu/Printer/Meat/Declaration/Rule.hs b/src/Ormolu/Printer/Meat/Declaration/Rule.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Rule.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Rule.hs
@@ -14,18 +14,17 @@
 import Ormolu.Printer.Meat.Declaration.Signature
 import Ormolu.Printer.Meat.Declaration.Value
 import Ormolu.Printer.Meat.Type
-import Ormolu.Utils
 
 p_ruleDecls :: RuleDecls GhcPs -> R ()
 p_ruleDecls = \case
-  HsRules NoExt _ xs ->
+  HsRules NoExtField _ xs ->
     pragma "RULES" . sitcc $
       sep breakpoint (sitcc . located' p_ruleDecl) xs
-  XRuleDecls NoExt -> notImplemented "XRuleDecls"
+  XRuleDecls x -> noExtCon x
 
 p_ruleDecl :: RuleDecl GhcPs -> R ()
 p_ruleDecl = \case
-  HsRule NoExt ruleName activation tyvars ruleBndrs lhs rhs -> do
+  HsRule NoExtField ruleName activation tyvars ruleBndrs lhs rhs -> do
     located ruleName p_ruleName
     space
     p_activation activation
@@ -33,13 +32,13 @@
     case tyvars of
       Nothing -> return ()
       Just xs -> do
-        p_forallBndrs p_hsTyVarBndr xs
+        p_forallBndrs ForallInvis p_hsTyVarBndr xs
         space
     -- It appears that there is no way to tell if there was an empty forall
     -- in the input or no forall at all. We do not want to add redundant
     -- foralls, so let's just skip the empty ones.
     unless (null ruleBndrs) $
-      p_forallBndrs p_ruleBndr ruleBndrs
+      p_forallBndrs ForallInvis p_ruleBndr ruleBndrs
     breakpoint
     inci $ do
       located lhs p_hsExpr
@@ -48,15 +47,15 @@
       inci $ do
         breakpoint
         located rhs p_hsExpr
-  XRuleDecl NoExt -> notImplemented "XRuleDecl"
+  XRuleDecl x -> noExtCon x
 
 p_ruleName :: (SourceText, RuleName) -> R ()
-p_ruleName (_, name) = atom $ HsString NoSourceText name
+p_ruleName (_, name) = atom $ (HsString NoSourceText name :: HsLit GhcPs)
 
 p_ruleBndr :: RuleBndr GhcPs -> R ()
 p_ruleBndr = \case
-  RuleBndr NoExt x -> p_rdrName x
-  RuleBndrSig NoExt x hswc -> parens N $ do
+  RuleBndr NoExtField x -> p_rdrName x
+  RuleBndrSig NoExtField x hswc -> parens N $ do
     p_rdrName x
     p_typeAscription hswc
-  XRuleBndr NoExt -> notImplemented "XRuleBndr"
+  XRuleBndr x -> noExtCon x
diff --git a/src/Ormolu/Printer/Meat/Declaration/Signature.hs b/src/Ormolu/Printer/Meat/Declaration/Signature.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Signature.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Signature.hs
@@ -7,6 +7,7 @@
   ( p_sigDecl,
     p_typeAscription,
     p_activation,
+    p_standaloneKindSig,
   )
 where
 
@@ -22,16 +23,16 @@
 
 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
+  TypeSig NoExtField names hswc -> p_typeSig True names hswc
+  PatSynSig NoExtField names hsib -> p_patSynSig names hsib
+  ClassOpSig NoExtField def names hsib -> p_classOpSig def names hsib
+  FixSig NoExtField sig -> p_fixSig sig
+  InlineSig NoExtField name inlinePragma -> p_inlineSig name inlinePragma
+  SpecSig NoExtField name ts inlinePragma -> p_specSig name ts inlinePragma
+  SpecInstSig NoExtField _ hsib -> p_specInstSig hsib
+  MinimalSig NoExtField _ booleanFormula -> p_minimalSig booleanFormula
+  CompleteMatchSig NoExtField _sourceText cs ty -> p_completeSig cs ty
+  SCCFunSig NoExtField _ name literal -> p_sccSig name literal
   _ -> notImplemented "certain types of signature declarations"
 
 p_typeSig ::
@@ -65,7 +66,7 @@
       then newline
       else breakpoint
     located t p_hsType
-p_typeAscription (XHsWildCardBndrs NoExt) = notImplemented "XHsWildCardBndrs"
+p_typeAscription (XHsWildCardBndrs x) = noExtCon x
 
 p_patSynSig ::
   [Located RdrName] ->
@@ -73,7 +74,7 @@
   R ()
 p_patSynSig names hsib = do
   txt "pattern"
-  let body = p_typeSig False names HsWC {hswc_ext = NoExt, hswc_body = hsib}
+  let body = p_typeSig False names HsWC {hswc_ext = NoExtField, hswc_body = hsib}
   if length names > 1
     then breakpoint >> inci body
     else space >> body
@@ -88,13 +89,13 @@
   R ()
 p_classOpSig def names hsib = do
   when def (txt "default" >> space)
-  p_typeSig True names HsWC {hswc_ext = NoExt, hswc_body = hsib}
+  p_typeSig True names HsWC {hswc_ext = NoExtField, hswc_body = hsib}
 
 p_fixSig ::
   FixitySig GhcPs ->
   R ()
 p_fixSig = \case
-  FixitySig NoExt names (Fixity _ n dir) -> do
+  FixitySig NoExtField names (Fixity _ n dir) -> do
     txt $ case dir of
       InfixL -> "infixl"
       InfixR -> "infixr"
@@ -103,7 +104,7 @@
     atom n
     space
     sitcc $ sep (comma >> breakpoint) p_rdrName names
-  XFixitySig NoExt -> notImplemented "XFixitySig"
+  XFixitySig x -> noExtCon x
 
 p_inlineSig ::
   -- | Name
@@ -218,3 +219,16 @@
   forM_ literal $ \x -> do
     breakpoint
     atom x
+
+p_standaloneKindSig :: StandaloneKindSig GhcPs -> R ()
+p_standaloneKindSig (StandaloneKindSig NoExtField name bndrs) = do
+  txt "type"
+  space
+  p_rdrName name
+  space
+  txt "::"
+  breakpoint
+  inci $ case bndrs of
+    HsIB NoExtField sig -> located sig p_hsType
+    XHsImplicitBndrs x -> noExtCon x
+p_standaloneKindSig (XStandaloneKindSig c) = noExtCon c
diff --git a/src/Ormolu/Printer/Meat/Declaration/Splice.hs b/src/Ormolu/Printer/Meat/Declaration/Splice.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Splice.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Splice.hs
@@ -8,9 +8,8 @@
 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"
+  SpliceDecl NoExtField splice _explicit -> located splice p_hsSplice
+  XSpliceDecl x -> noExtCon x
diff --git a/src/Ormolu/Printer/Meat/Declaration/Type.hs b/src/Ormolu/Printer/Meat/Declaration/Type.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Type.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Type.hs
@@ -11,9 +11,6 @@
 import Ormolu.Printer.Combinators
 import Ormolu.Printer.Meat.Common
 import Ormolu.Printer.Meat.Type
-import Ormolu.Utils (notImplemented)
-import RdrName (RdrName (..))
-import SrcLoc (Located)
 
 p_synDecl ::
   -- | Type constructor
@@ -38,4 +35,4 @@
   txt "="
   breakpoint
   inci (located t p_hsType)
-p_synDecl _ _ XLHsQTyVars {} _ = notImplemented "XLHsQTyVars"
+p_synDecl _ _ (XLHsQTyVars x) _ = noExtCon x
diff --git a/src/Ormolu/Printer/Meat/Declaration/TypeFamily.hs b/src/Ormolu/Printer/Meat/Declaration/TypeFamily.hs
--- a/src/Ormolu/Printer/Meat/Declaration/TypeFamily.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/TypeFamily.hs
@@ -9,15 +9,13 @@
   )
 where
 
-import BasicTypes (LexicalFixity (..))
 import Control.Monad
-import Data.Maybe (isJust, isNothing)
+import Data.Maybe (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 {fdTyVars = HsQTvs {..}, ..} = do
@@ -36,17 +34,18 @@
         inci
         (p_rdrName fdLName)
         (located' p_hsTyVarBndr <$> hsq_explicit)
-    let rsig = p_familyResultSigL fdResultSig
-    unless (isNothing rsig && isNothing fdInjectivityAnn) space
+    let resultSig = p_familyResultSigL fdResultSig
+    unless (isNothing resultSig && isNothing fdInjectivityAnn) space
     inci $ do
-      sequence_ rsig
-      when (isJust rsig && isJust fdInjectivityAnn) breakpoint
+      sequence_ resultSig
+      space
       forM_ fdInjectivityAnn (located' p_injectivityAnn)
   case mmeqs of
     Nothing -> return ()
     Just meqs -> do
-      space
-      txt "where"
+      inci $ do
+        breakpoint
+        txt "where"
       case meqs of
         Nothing -> do
           space
@@ -56,7 +55,7 @@
           sep newline (located' (inci . p_tyFamInstEqn)) eqs
 p_famDecl _ FamilyDecl {fdTyVars = XLHsQTyVars {}} =
   notImplemented "XLHsQTyVars"
-p_famDecl _ (XFamilyDecl NoExt) = notImplemented "XFamilyDecl"
+p_famDecl _ (XFamilyDecl x) = noExtCon x
 
 p_familyResultSigL ::
   Located (FamilyResultSig GhcPs) ->
@@ -64,17 +63,17 @@
 p_familyResultSigL l =
   case l of
     L _ a -> case a of
-      NoSig NoExt -> Nothing
-      KindSig NoExt k -> Just $ do
+      NoSig NoExtField -> Nothing
+      KindSig NoExtField k -> Just $ do
         txt "::"
         breakpoint
         located k p_hsType
-      TyVarSig NoExt bndr -> Just $ do
+      TyVarSig NoExtField bndr -> Just $ do
         txt "="
         breakpoint
         located bndr p_hsTyVarBndr
-      XFamilyResultSig NoExt ->
-        notImplemented "XFamilyResultSig"
+      XFamilyResultSig x ->
+        noExtCon x
 
 p_injectivityAnn :: InjectivityAnn GhcPs -> R ()
 p_injectivityAnn (InjectivityAnn a bs) = do
@@ -91,7 +90,7 @@
   case feqn_bndrs of
     Nothing -> return ()
     Just bndrs -> do
-      p_forallBndrs p_hsTyVarBndr bndrs
+      p_forallBndrs ForallInvis p_hsTyVarBndr bndrs
       breakpoint
   (if null feqn_bndrs then id else inci) $ do
     let famLhsSpn = getLoc feqn_tycon : fmap (getLoc . typeArgToType) feqn_pats
@@ -105,8 +104,8 @@
     txt "="
     breakpoint
     inci (located feqn_rhs p_hsType)
-p_tyFamInstEqn HsIB {hsib_body = XFamEqn {}} = notImplemented "HsIB XFamEqn"
-p_tyFamInstEqn (XHsImplicitBndrs NoExt) = notImplemented "XHsImplicitBndrs"
+p_tyFamInstEqn HsIB {hsib_body = XFamEqn x} = noExtCon x
+p_tyFamInstEqn (XHsImplicitBndrs x) = noExtCon x
 
 ----------------------------------------------------------------------------
 -- Helpers
diff --git a/src/Ormolu/Printer/Meat/Declaration/Value.hs b/src/Ormolu/Printer/Meat/Declaration/Value.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Value.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Value.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE TypeApplications #-}
 
 module Ormolu.Printer.Meat.Declaration.Value
   ( p_valDecl,
@@ -20,7 +21,7 @@
 import Data.Data hiding (Infix, Prefix)
 import Data.Functor ((<&>))
 import Data.List (intersperse, sortOn)
-import Data.List.NonEmpty ((<|), NonEmpty ((:|)))
+import Data.List.NonEmpty ((<|), NonEmpty (..))
 import qualified Data.List.NonEmpty as NE
 import Data.Text (Text)
 import qualified Data.Text as Text
@@ -34,8 +35,6 @@
 import Ormolu.Printer.Meat.Type
 import Ormolu.Printer.Operators
 import Ormolu.Utils
-import RdrName (RdrName (..), rdrNameOcc)
-import SrcLoc (combineSrcSpans, isOneLineSpan)
 
 -- | Style of a group of equations.
 data MatchGroupStyle
@@ -65,12 +64,12 @@
 
 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
+  FunBind NoExtField funId funMatches _ _ -> p_funBind funId funMatches
+  PatBind NoExtField 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"
+  PatSynBind NoExtField psb -> p_patSynBind psb
+  XHsBindsLR x -> noExtCon x
 
 p_funBind ::
   Located RdrName ->
@@ -114,8 +113,8 @@
         (matchStrictness m)
         m_pats
         m_grhss
-    p_Match _ = notImplemented "XMatch"
-p_matchGroup' _ _ _ (XMatchGroup NoExt) = notImplemented "XMatchGroup"
+    p_Match (XMatch x) = noExtCon x
+p_matchGroup' _ _ _ (XMatchGroup x) = noExtCon x
 
 -- | Function id obtained through pattern matching on 'FunBind' should not
 -- be used to print the actual equations because the different ‘RdrNames’
@@ -193,14 +192,14 @@
               then id
               else inci
       switchLayout [combinedSpans] $ do
-        let stdCase = sep breakpoint p_pat m_pats
+        let stdCase = sep breakpoint (located' p_pat) m_pats
         case style of
           Function name ->
             p_infixDefHelper
               isInfix
               inci'
               (p_rdrName name)
-              (p_pat <$> m_pats)
+              (located' p_pat <$> m_pats)
           PatternBind -> stdCase
           Case -> stdCase
           Lambda -> do
@@ -266,7 +265,7 @@
     switchLayout [patGrhssSpan] $
       placeHanging placement p_body
     inci p_where
-p_match' _ _ _ _ _ _ XGRHSs {} = notImplemented "XGRHSs"
+p_match' _ _ _ _ _ _ (XGRHSs x) = noExtCon x
 
 p_grhs :: GroupStyle -> GRHS GhcPs (LHsExpr GhcPs) -> R ()
 p_grhs = p_grhs' exprPlacement p_hsExpr
@@ -280,7 +279,7 @@
   GroupStyle ->
   GRHS GhcPs (Located body) ->
   R ()
-p_grhs' placer render style (GRHS NoExt guards body) =
+p_grhs' placer render style (GRHS NoExtField guards body) =
   case guards of
     [] -> p_body
     xs -> do
@@ -305,54 +304,55 @@
         Nothing -> Nothing
         Just gs -> (Just . srcSpanEnd . getLoc . NE.last) gs
     p_body = located body render
-p_grhs' _ _ _ (XGRHS NoExt) = notImplemented "XGRHS"
+p_grhs' _ _ _ (XGRHS x) = noExtCon x
 
 p_hsCmd :: HsCmd GhcPs -> R ()
 p_hsCmd = \case
-  HsCmdArrApp NoExt body input arrType _ -> do
+  HsCmdArrApp NoExtField 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
+    breakpoint
+    inci $ do
+      case arrType of
+        HsFirstOrderApp -> txt "-<"
+        HsHigherOrderApp -> txt "-<<"
+      placeHanging (exprPlacement (unLoc input)) $
+        located input p_hsExpr
+  HsCmdArrForm NoExtField 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
+  HsCmdArrForm NoExtField 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"
+  HsCmdArrForm NoExtField _ 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 ->
+  HsCmdLam NoExtField mgroup -> p_matchGroup' cmdPlacement p_hsCmd Lambda mgroup
+  HsCmdPar NoExtField c -> parens N (located c p_hsCmd)
+  HsCmdCase NoExtField e mgroup ->
     p_case cmdPlacement p_hsCmd e mgroup
-  HsCmdIf NoExt _ if' then' else' ->
+  HsCmdIf NoExtField _ if' then' else' ->
     p_if cmdPlacement p_hsCmd if' then' else'
-  HsCmdLet NoExt localBinds c ->
+  HsCmdLet NoExtField localBinds c ->
     p_let p_hsCmd localBinds c
-  HsCmdDo NoExt es -> do
+  HsCmdDo NoExtField es -> do
     txt "do"
     newline
     inci . located es $
       sitcc . sep newline (located' (sitcc . p_stmt' cmdPlacement p_hsCmd))
   HsCmdWrap {} -> notImplemented "HsCmdWrap"
-  XCmd {} -> notImplemented "XCmd"
+  XCmd x -> noExtCon x
 
 p_hsCmdTop :: HsCmdTop GhcPs -> R ()
 p_hsCmdTop = \case
-  HsCmdTop NoExt cmd -> located cmd p_hsCmd
-  XCmdTop {} -> notImplemented "XHsCmdTop"
+  HsCmdTop NoExtField cmd -> located cmd p_hsCmd
+  XCmdTop x -> noExtCon x
 
 p_stmt :: Stmt GhcPs (LHsExpr GhcPs) -> R ()
 p_stmt = p_stmt' exprPlacement p_hsExpr
@@ -367,16 +367,13 @@
   Stmt GhcPs (Located body) ->
   R ()
 p_stmt' placer render = \case
-  LastStmt NoExt body _ _ -> located body render
-  BindStmt NoExt p f _ _ -> do
-    p_pat p
+  LastStmt NoExtField body _ _ -> located body render
+  BindStmt NoExtField p f _ _ -> do
+    located p p_pat
     space
     txt "<-"
-    -- https://gitlab.haskell.org/ghc/ghc/issues/17330
-    let loc = case p of
-          XPat pat -> getLoc pat
-          _ -> error "p_stmt': BindStmt: Pat does not contain a location"
-    let placement =
+    let loc = getLoc p
+        placement =
           case f of
             L l' x ->
               if isOneLineSpan
@@ -386,8 +383,8 @@
     switchLayout [loc, getLoc f] $
       placeHanging placement (located f render)
   ApplicativeStmt {} -> notImplemented "ApplicativeStmt" -- generated by renamer
-  BodyStmt NoExt body _ _ -> located body render
-  LetStmt NoExt binds -> do
+  BodyStmt NoExtField body _ _ -> located body render
+  LetStmt NoExtField binds -> do
     txt "let"
     space
     sitcc $ located binds p_hsLocalBinds
@@ -429,10 +426,10 @@
     txt "rec"
     space
     sitcc $ sepSemi (located' (p_stmt' placer render)) recS_stmts
-  XStmtLR {} -> notImplemented "XStmtLR"
+  XStmtLR c -> noExtCon c
 
 gatherStmt :: ExprLStmt GhcPs -> [[ExprLStmt GhcPs]]
-gatherStmt (L _ (ParStmt NoExt block _ _)) =
+gatherStmt (L _ (ParStmt NoExtField block _ _)) =
   foldr ((<>) . gatherStmtBlock) [] block
 gatherStmt (L s stmt@TransStmt {..}) =
   foldr liftAppend [] ((gatherStmt <$> trS_stmts) <> pure [[L s stmt]])
@@ -441,11 +438,11 @@
 gatherStmtBlock :: ParStmtBlock GhcPs GhcPs -> [[ExprLStmt GhcPs]]
 gatherStmtBlock (ParStmtBlock _ stmts _ _) =
   foldr (liftAppend . gatherStmt) [] stmts
-gatherStmtBlock XParStmtBlock {} = notImplemented "XParStmtBlock"
+gatherStmtBlock (XParStmtBlock x) = noExtCon x
 
 p_hsLocalBinds :: HsLocalBindsLR GhcPs GhcPs -> R ()
 p_hsLocalBinds = \case
-  HsValBinds NoExt (ValBinds NoExt bag lsigs) -> do
+  HsValBinds NoExtField (ValBinds NoExtField bag lsigs) -> do
     let ssStart =
           either
             (srcSpanStart . getLoc)
@@ -467,20 +464,23 @@
       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) ->
+  HsValBinds NoExtField _ -> notImplemented "HsValBinds"
+  HsIPBinds NoExtField (IPBinds NoExtField xs) ->
     -- Second argument of IPBind is always Left before type-checking.
-    let p_ipBind (IPBind NoExt (Left name) expr) = do
+    let p_ipBind (IPBind NoExtField (Left name) expr) = do
           atom name
           space
           txt "="
           breakpoint
           useBraces $ inci $ located expr p_hsExpr
-        p_ipBind _ = notImplemented "XHsIPBinds"
+        p_ipBind (IPBind NoExtField (Right _) _) =
+          -- Should only occur after the type checker
+          notImplemented "IPBind _ (Right _) _"
+        p_ipBind (XIPBind x) = noExtCon x
      in sepSemi (located' p_ipBind) xs
-  HsIPBinds NoExt _ -> notImplemented "HsIpBinds"
-  EmptyLocalBinds NoExt -> return ()
-  XHsLocalBindsLR _ -> notImplemented "XHsLocalBindsLR"
+  HsIPBinds NoExtField _ -> notImplemented "HsIpBinds"
+  EmptyLocalBinds NoExtField -> return ()
+  XHsLocalBindsLR x -> noExtCon x
 
 p_hsRecField ::
   HsRecField' RdrName (LHsExpr GhcPs) ->
@@ -495,42 +495,42 @@
 
 p_hsTupArg :: HsTupArg GhcPs -> R ()
 p_hsTupArg = \case
-  Present NoExt x -> located x p_hsExpr
-  Missing NoExt -> pure ()
-  XTupArg {} -> notImplemented "XTupArg"
+  Present NoExtField x -> located x p_hsExpr
+  Missing NoExtField -> pure ()
+  XTupArg x -> noExtCon x
 
 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 ->
+  HsVar NoExtField name -> p_rdrName name
+  HsUnboundVar NoExtField v -> atom (unboundVarOcc v)
+  HsConLikeOut NoExtField _ -> notImplemented "HsConLikeOut"
+  HsRecFld NoExtField x ->
     case x of
-      Unambiguous NoExt name -> p_rdrName name
-      Ambiguous NoExt name -> p_rdrName name
-      XAmbiguousFieldOcc NoExt -> notImplemented "XAmbiguousFieldOcc"
-  HsOverLabel NoExt _ v -> do
+      Unambiguous NoExtField name -> p_rdrName name
+      Ambiguous NoExtField name -> p_rdrName name
+      XAmbiguousFieldOcc xx -> noExtCon xx
+  HsOverLabel NoExtField _ v -> do
     txt "#"
     atom v
-  HsIPVar NoExt (HsIPName name) -> do
+  HsIPVar NoExtField (HsIPName name) -> do
     txt "?"
     atom name
-  HsOverLit NoExt v -> atom (ol_val v)
-  HsLit NoExt lit ->
+  HsOverLit NoExtField v -> atom (ol_val v)
+  HsLit NoExtField lit ->
     case lit of
       HsString (SourceText stxt) _ -> p_stringLit stxt
       HsStringPrim (SourceText stxt) _ -> p_stringLit stxt
       r -> atom r
-  HsLam NoExt mgroup ->
+  HsLam NoExtField mgroup ->
     p_matchGroup Lambda mgroup
-  HsLamCase NoExt mgroup -> do
+  HsLamCase NoExtField mgroup -> do
     txt "\\case"
     breakpoint
     inci (p_matchGroup LambdaCase mgroup)
-  HsApp NoExt f x -> do
+  HsApp NoExtField 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.
@@ -564,9 +564,9 @@
             -- expression is parenthesised.
             indent =
               case func of
-                L _ (HsPar NoExt _) -> inci
-                L _ (HsAppType NoExt _ _) -> inci
-                L _ (HsMultiIf NoExt _) -> inci
+                L _ (HsPar NoExtField _) -> inci
+                L _ (HsAppType NoExtField _ _) -> inci
+                L _ (HsMultiIf NoExtField _) -> inci
                 L spn _ ->
                   if isOneLineSpan spn
                     then inci
@@ -588,35 +588,35 @@
           sep breakpoint (located' p_hsExpr) initp
         placeHanging placement $
           located lastp p_hsExpr
-  HsAppType NoExt e a -> do
+  HsAppType NoExtField e a -> do
     located e p_hsExpr
     breakpoint
     inci $ do
       txt "@"
       located (hswc_body a) p_hsType
-  OpApp NoExt x op y -> do
+  OpApp NoExtField x op y -> do
     let opTree = OpBranch (exprOpTree x) op (exprOpTree y)
     p_exprOpTree True s (reassociateOpTree getOpName opTree)
-  NegApp NoExt e _ -> do
+  NegApp NoExtField e _ -> do
     txt "-"
     space
     located e p_hsExpr
-  HsPar NoExt e ->
+  HsPar NoExtField e ->
     parens s (located e (dontUseBraces . p_hsExpr))
-  SectionL NoExt x op -> do
+  SectionL NoExtField x op -> do
     located x p_hsExpr
     breakpoint
     inci (located op p_hsExpr)
-  SectionR NoExt op x -> do
+  SectionR NoExtField op x -> do
     located op p_hsExpr
     useRecordDot' <- useRecordDot
     let isRecordDot' = isRecordDot (unLoc op) (getLoc x)
     unless (useRecordDot' && isRecordDot') breakpoint
     inci (located x p_hsExpr)
-  ExplicitTuple NoExt args boxity -> do
+  ExplicitTuple NoExtField args boxity -> do
     let isSection = any (isMissing . unLoc) args
         isMissing = \case
-          Missing NoExt -> True
+          Missing NoExtField -> True
           _ -> False
     let parens' =
           case boxity of
@@ -629,18 +629,18 @@
       else
         switchLayout (getLoc <$> args) . parens' s . sitcc $
           sep (comma >> breakpoint) (sitcc . located' p_hsTupArg) args
-  ExplicitSum NoExt tag arity e ->
+  ExplicitSum NoExtField tag arity e ->
     p_unboxedSum N tag arity (located e p_hsExpr)
-  HsCase NoExt e mgroup ->
+  HsCase NoExtField e mgroup ->
     p_case exprPlacement p_hsExpr e mgroup
-  HsIf NoExt _ if' then' else' ->
+  HsIf NoExtField _ if' then' else' ->
     p_if exprPlacement p_hsExpr if' then' else'
-  HsMultiIf NoExt guards -> do
+  HsMultiIf NoExtField guards -> do
     txt "if "
     inci . inci . sitcc $ sep newline (located' (p_grhs RightArrow)) guards
-  HsLet NoExt localBinds e ->
+  HsLet NoExtField localBinds e ->
     p_let p_hsExpr localBinds e
-  HsDo NoExt ctx es -> do
+  HsDo NoExtField ctx es -> do
     let doBody header = do
           txt header
           breakpoint
@@ -685,10 +685,10 @@
     breakpoint
     let HsRecFields {..} = rcon_flds
         updName f =
-          f
+          (f :: HsRecField GhcPs (LHsExpr GhcPs))
             { hsRecFieldLbl = case unLoc $ hsRecFieldLbl f of
                 FieldOcc _ n -> n
-                XFieldOcc _ -> notImplemented "XFieldOcc"
+                XFieldOcc x -> noExtCon x
             }
         fields = located' (p_hsRecField . updName) <$> rec_flds
         dotdot =
@@ -708,27 +708,26 @@
             == (srcSpanStartCol <$> mrs (head rupd_flds))
     unless (useRecordDot' && isPluginForm) breakpoint
     let updName f =
-          f
+          (f :: HsRecUpdField GhcPs)
             { hsRecFieldLbl = case unLoc $ hsRecFieldLbl f of
                 Ambiguous _ n -> n
                 Unambiguous _ n -> n
-                XAmbiguousFieldOcc _ -> notImplemented "XAmbiguousFieldOcc"
+                XAmbiguousFieldOcc x -> noExtCon x
             }
     inci . braces N . sitcc $
       sep
         (comma >> breakpoint)
         (sitcc . located' (p_hsRecField . updName))
         rupd_flds
-  ExprWithTySig NoExt x HsWC {hswc_body = HsIB {..}} -> sitcc $ do
+  ExprWithTySig NoExtField x HsWC {hswc_body = HsIB {..}} -> sitcc $ do
     located x p_hsExpr
     space
     txt "::"
     breakpoint
     inci $ located hsib_body p_hsType
-  ExprWithTySig NoExt _ HsWC {hswc_body = XHsImplicitBndrs {}} ->
-    notImplemented "XHsImplicitBndrs"
-  ExprWithTySig NoExt _ XHsWildCardBndrs {} -> notImplemented "XHsWildCardBndrs"
-  ArithSeq NoExt _ x ->
+  ExprWithTySig NoExtField _ HsWC {hswc_body = XHsImplicitBndrs x} -> noExtCon x
+  ExprWithTySig NoExtField _ (XHsWildCardBndrs x) -> noExtCon x
+  ArithSeq NoExtField _ x ->
     case x of
       From from -> brackets s . sitcc $ do
         located from p_hsExpr
@@ -750,25 +749,25 @@
         txt ".."
         space
         located to p_hsExpr
-  HsSCC NoExt _ name x -> do
+  HsSCC NoExtField _ name x -> do
     txt "{-# SCC "
     atom name
     txt " #-}"
     breakpoint
     located x p_hsExpr
-  HsCoreAnn NoExt _ value x -> do
+  HsCoreAnn NoExtField _ value x -> do
     txt "{-# CORE "
     atom value
     txt " #-}"
     breakpoint
     located x p_hsExpr
-  HsBracket NoExt x -> p_hsBracket x
+  HsBracket NoExtField x -> p_hsBracket x
   HsRnBracketOut {} -> notImplemented "HsRnBracketOut"
   HsTcBracketOut {} -> notImplemented "HsTcBracketOut"
-  HsSpliceE NoExt splice -> p_hsSplice splice
-  HsProc NoExt p e -> do
+  HsSpliceE NoExtField splice -> p_hsSplice splice
+  HsProc NoExtField p e -> do
     txt "proc"
-    locatedPat p $ \x -> do
+    located p $ \x -> do
       breakpoint
       inci (p_pat x)
       breakpoint
@@ -779,31 +778,11 @@
     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"
+  XExpr x -> noExtCon x
 
 p_patSynBind :: PatSynBind GhcPs GhcPs -> R ()
 p_patSynBind PSB {..} = do
@@ -813,15 +792,15 @@
           Unidirectional -> do
             txt "<-"
             breakpoint
-            p_pat psb_def
+            located psb_def p_pat
           ImplicitBidirectional -> do
             txt "="
             breakpoint
-            p_pat psb_def
+            located psb_def p_pat
           ExplicitBidirectional mgroup -> do
             txt "<-"
             breakpoint
-            p_pat psb_def
+            located psb_def p_pat
             newline
             txt "where"
             newline
@@ -855,7 +834,7 @@
           space
           p_rdrName r
       inci rhs
-p_patSynBind (XPatSynBind NoExt) = notImplemented "XPatSynBind"
+p_patSynBind (XPatSynBind x) = noExtCon x
 
 p_case ::
   Data body =>
@@ -922,40 +901,37 @@
 
 p_pat :: Pat GhcPs -> R ()
 p_pat = \case
-  -- Note: starting from GHC 8.8, 'LPat' == 'Pat'. Located 'Pat's are always
-  -- constructed with the 'XPat' constructor, containing a @Located Pat@.
-  XPat pat -> located pat p_pat
-  WildPat NoExt -> txt "_"
-  VarPat NoExt name -> p_rdrName name
-  LazyPat NoExt pat -> do
+  WildPat NoExtField -> txt "_"
+  VarPat NoExtField name -> p_rdrName name
+  LazyPat NoExtField pat -> do
     txt "~"
-    p_pat pat
-  AsPat NoExt name pat -> do
+    located pat p_pat
+  AsPat NoExtField name pat -> do
     p_rdrName name
     txt "@"
-    p_pat pat
-  ParPat NoExt pat ->
-    locatedPat pat (parens S . p_pat)
-  BangPat NoExt pat -> do
+    located pat p_pat
+  ParPat NoExtField pat ->
+    located pat (parens S . p_pat)
+  BangPat NoExtField pat -> do
     txt "!"
-    p_pat pat
-  ListPat NoExt pats ->
-    brackets S . sitcc $ sep (comma >> breakpoint) p_pat pats
-  TuplePat NoExt pats boxing -> do
+    located pat p_pat
+  ListPat NoExtField pats ->
+    brackets S . sitcc $ sep (comma >> breakpoint) (located' p_pat) pats
+  TuplePat NoExtField pats boxing -> do
     let f =
           case boxing of
             Boxed -> parens S
             Unboxed -> parensHash S
-    f . sitcc $ sep (comma >> breakpoint) (sitcc . p_pat) pats
-  SumPat NoExt pat tag arity ->
-    p_unboxedSum S tag arity (p_pat pat)
+    f . sitcc $ sep (comma >> breakpoint) (sitcc . located' p_pat) pats
+  SumPat NoExtField 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 . p_pat) xs
+          inci . sitcc $ sep breakpoint (sitcc . located' p_pat) xs
       RecCon (HsRecFields fields dotdot) -> do
         p_rdrName pat
         breakpoint
@@ -965,34 +941,37 @@
         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
-        p_pat x
-        space
-        p_rdrName pat
-        breakpoint
-        inci (p_pat y)
+            Just (L _ n) -> (Just <$> take n fields) ++ [Nothing]
+      InfixCon l r -> do
+        switchLayout [getLoc l, getLoc r] $ do
+          located l p_pat
+          breakpoint
+          inci $ do
+            p_rdrName pat
+            space
+            located r p_pat
   ConPatOut {} -> notImplemented "ConPatOut" -- presumably created by renamer?
-  ViewPat NoExt expr pat -> sitcc $ do
+  ViewPat NoExtField expr pat -> sitcc $ do
     located expr p_hsExpr
     space
     txt "->"
     breakpoint
-    inci (p_pat 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
+    inci (located pat p_pat)
+  SplicePat NoExtField splice -> p_hsSplice splice
+  LitPat NoExtField p -> atom p
+  NPat NoExtField v _ _ -> located v (atom . ol_val)
+  NPlusKPat NoExtField n k _ _ _ -> sitcc $ do
     p_rdrName n
     breakpoint
     inci $ do
       txt "+"
       space
       located k (atom . ol_val)
-  SigPat NoExt pat hswc -> do
-    p_pat pat
+  SigPat NoExtField pat hswc -> do
+    located pat p_pat
     p_typeAscription hswc
   CoPat {} -> notImplemented "CoPat" -- apparently created at some later stage
+  XPat x -> noExtCon x
 
 p_pat_hsRecField :: HsRecField' (FieldOcc GhcPs) (LPat GhcPs) -> R ()
 p_pat_hsRecField HsRecField {..} = do
@@ -1002,7 +981,7 @@
     space
     txt "="
     breakpoint
-    inci (p_pat hsRecFieldArg)
+    inci (located hsRecFieldArg p_pat)
 
 p_unboxedSum :: BracketStyle -> ConTag -> Arity -> R () -> R ()
 p_unboxedSum s tag arity m = do
@@ -1023,9 +1002,9 @@
 
 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
+  HsTypedSplice NoExtField deco _ expr -> p_hsSpliceTH True expr deco
+  HsUntypedSplice NoExtField deco _ expr -> p_hsSpliceTH False expr deco
+  HsQuasiQuote NoExtField _ quoterName srcSpan str -> do
     txt "["
     p_rdrName (L srcSpan quoterName)
     txt "|"
@@ -1035,7 +1014,7 @@
     txt "|]"
   HsSpliced {} -> notImplemented "HsSpliced"
   HsSplicedT {} -> notImplemented "HsSplicedT"
-  XSplice {} -> notImplemented "XSplice"
+  XSplice x -> noExtCon x
 
 p_hsSpliceTH ::
   -- | Typed splice?
@@ -1059,17 +1038,17 @@
 
 p_hsBracket :: HsBracket GhcPs -> R ()
 p_hsBracket = \case
-  ExpBr NoExt expr -> do
+  ExpBr NoExtField expr -> do
     anns <- getEnclosingAnns
     let name = case anns of
           AnnOpenEQ : _ -> ""
           _ -> "e"
     quote name (located expr p_hsExpr)
-  PatBr NoExt pat -> quote "p" (p_pat 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
+  PatBr NoExtField pat -> located pat (quote "p" . p_pat)
+  DecBrL NoExtField decls -> quote "d" (p_hsDecls Free decls)
+  DecBrG NoExtField _ -> notImplemented "DecBrG" -- result of renamer
+  TypBr NoExtField ty -> quote "t" (located ty p_hsType)
+  VarBr NoExtField 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
@@ -1084,13 +1063,13 @@
             && not (doesNotNeedExtraParens name)
         wrapper = if isOperator then parens N else id
     wrapper $ p_rdrName (noLoc name)
-  TExpBr NoExt expr -> do
+  TExpBr NoExtField expr -> do
     txt "[||"
     breakpoint'
     located expr p_hsExpr
     breakpoint'
     txt "||]"
-  XBracket {} -> notImplemented "XBracket"
+  XBracket x -> noExtCon x
   where
     quote :: Text -> R () -> R ()
     quote name body = do
@@ -1169,9 +1148,9 @@
 liftAppend (x : xs) (y : ys) = x <> y : liftAppend xs ys
 
 getGRHSSpan :: GRHS GhcPs (Located body) -> SrcSpan
-getGRHSSpan (GRHS NoExt guards body) =
+getGRHSSpan (GRHS NoExtField guards body) =
   combineSrcSpans' $ getLoc body :| map getLoc guards
-getGRHSSpan (XGRHS NoExt) = notImplemented "XGRHS"
+getGRHSSpan (XGRHS x) = noExtCon x
 
 -- | Place a thing that may have a hanging form. This function handles how
 -- to separate it from preceding expressions and whether to bump indentation
@@ -1192,67 +1171,63 @@
   (body -> Placement) ->
   [LGRHS GhcPs (Located body)] ->
   Placement
-blockPlacement placer [L _ (GRHS NoExt _ (L _ x))] = placer x
+blockPlacement placer [L _ (GRHS NoExtField _ (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
+  HsCmdLam NoExtField _ -> Hanging
+  HsCmdCase NoExtField _ _ -> Hanging
+  HsCmdDo NoExtField _ -> Hanging
   _ -> Normal
 
 cmdTopPlacement :: HsCmdTop GhcPs -> Placement
 cmdTopPlacement = \case
-  HsCmdTop NoExt (L _ x) -> cmdPlacement x
-  XCmdTop {} -> notImplemented "XCmdTop"
+  HsCmdTop NoExtField (L _ x) -> cmdPlacement x
+  XCmdTop x -> noExtCon x
 
 -- | 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) _)]) _
+  HsLam NoExtField mg -> case mg of
+    MG _ (L _ [L _ (Match NoExtField _ (x : xs) _)]) _
       | isOneLineSpan (combineSrcSpans' $ fmap getLoc (x :| xs)) ->
         Hanging
     _ -> Normal
-  HsLamCase NoExt _ -> Hanging
-  HsCase NoExt _ _ -> Hanging
-  HsDo NoExt DoExpr _ -> Hanging
-  HsDo NoExt MDoExpr _ -> Hanging
+  HsLamCase NoExtField _ -> Hanging
+  HsCase NoExtField _ _ -> Hanging
+  HsDo NoExtField DoExpr _ -> Hanging
+  HsDo NoExtField MDoExpr _ -> 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)
+  OpApp NoExtField _ _ y -> exprPlacement (unLoc y)
   -- Same thing for function applications (usually with -XBlockArguments)
-  HsApp NoExt _ y -> exprPlacement (unLoc y)
-  HsProc NoExt p _ ->
-    -- https://gitlab.haskell.org/ghc/ghc/issues/17330
-    let loc = case p of
-          XPat pat -> getLoc pat
-          _ -> error "exprPlacement: HsProc: Pat does not contain a location"
-     in -- Indentation breaks if pattern is longer than one line and left
-        -- hanging. Consequently, only apply hanging when it is safe.
-        if isOneLineSpan loc
-          then Hanging
-          else Normal
+  HsApp NoExtField _ y -> exprPlacement (unLoc y)
+  HsProc NoExtField p _ ->
+    -- Indentation breaks if pattern is longer than one line and left
+    -- hanging. Consequently, only apply hanging when it is safe.
+    if isOneLineSpan (getLoc p)
+      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 (GRHS NoExtField [] _) = 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 (L _ (OpApp NoExtField 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
+  HsVar NoExtField (L _ a) -> Just a
   _ -> Nothing
 
 p_exprOpTree ::
@@ -1274,8 +1249,10 @@
             OpNode (L _ n) -> exprPlacement n
             _ -> Normal
           else Normal
+      -- Distinguish holes used in infix notation.
+      -- eg. '1 _foo 2' and '1 `_foo` 2'
       opWrapper = case unLoc op of
-        EWildPat NoExt -> backticks
+        HsUnboundVar NoExtField _ -> backticks
         _ -> id
   layout <- getLayout
   let ub = case layout of
@@ -1330,7 +1307,7 @@
   SrcSpan ->
   Bool
 isRecordDot op (RealSrcSpan ySpan) = case op of
-  HsVar NoExt (L (RealSrcSpan opSpan) opName) ->
+  HsVar NoExtField (L (RealSrcSpan opSpan) opName) ->
     isDot opName && (srcSpanEndCol opSpan == srcSpanStartCol ySpan)
   _ -> False
 isRecordDot _ _ = False
diff --git a/src/Ormolu/Printer/Meat/Declaration/Warning.hs b/src/Ormolu/Printer/Meat/Declaration/Warning.hs
--- a/src/Ormolu/Printer/Meat/Declaration/Warning.hs
+++ b/src/Ormolu/Printer/Meat/Declaration/Warning.hs
@@ -13,17 +13,16 @@
 import GHC
 import Ormolu.Printer.Combinators
 import Ormolu.Printer.Meat.Common
-import Ormolu.Utils
 
 p_warnDecls :: WarnDecls GhcPs -> R ()
-p_warnDecls (Warnings NoExt _ warnings) =
+p_warnDecls (Warnings NoExtField _ warnings) =
   traverse_ (located' p_warnDecl) warnings
-p_warnDecls XWarnDecls {} = notImplemented "XWarnDecls"
+p_warnDecls (XWarnDecls x) = noExtCon x
 
 p_warnDecl :: WarnDecl GhcPs -> R ()
-p_warnDecl (Warning NoExt functions warningTxt) =
+p_warnDecl (Warning NoExtField functions warningTxt) =
   p_topLevelWarning functions warningTxt
-p_warnDecl XWarnDecl {} = notImplemented "XWarnDecl"
+p_warnDecl (XWarnDecl x) = noExtCon x
 
 p_moduleWarning :: WarningTxt -> R ()
 p_moduleWarning wtxt = do
diff --git a/src/Ormolu/Printer/Meat/ImportExport.hs b/src/Ormolu/Printer/Meat/ImportExport.hs
--- a/src/Ormolu/Printer/Meat/ImportExport.hs
+++ b/src/Ormolu/Printer/Meat/ImportExport.hs
@@ -11,10 +11,8 @@
 
 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
@@ -26,15 +24,17 @@
     layout <- getLayout
     sep breakpoint (sitcc . located' (uncurry (p_lie layout))) (attachPositions xs)
 
-p_hsmodImport :: ImportDecl GhcPs -> R ()
-p_hsmodImport ImportDecl {..} = do
+p_hsmodImport :: Bool -> ImportDecl GhcPs -> R ()
+p_hsmodImport useQualifiedPost ImportDecl {..} = do
   txt "import"
   space
   when ideclSource (txt "{-# SOURCE #-}")
   space
   when ideclSafe (txt "safe")
   space
-  when ideclQualified (txt "qualified")
+  when
+    (isImportDeclQualified ideclQualified && not useQualifiedPost)
+    (txt "qualified")
   space
   case ideclPkgQual of
     Nothing -> return ()
@@ -42,6 +42,9 @@
   space
   inci $ do
     located ideclName atom
+    when
+      (isImportDeclQualified ideclQualified && useQualifiedPost)
+      (space >> txt "qualified")
     case ideclAs of
       Nothing -> return ()
       Just l -> do
@@ -62,22 +65,22 @@
           layout <- getLayout
           sep breakpoint (sitcc . located' (uncurry (p_lie layout))) (attachPositions xs)
     newline
-p_hsmodImport (XImportDecl NoExt) = notImplemented "XImportDecl"
+p_hsmodImport _ (XImportDecl x) = noExtCon x
 
 p_lie :: Layout -> (Int, Int) -> IE GhcPs -> R ()
 p_lie encLayout (i, totalItems) = \case
-  IEVar NoExt l1 -> do
+  IEVar NoExtField l1 -> do
     located l1 p_ieWrappedName
     p_comma
-  IEThingAbs NoExt l1 -> do
+  IEThingAbs NoExtField l1 -> do
     located l1 p_ieWrappedName
     p_comma
-  IEThingAll NoExt l1 -> do
+  IEThingAll NoExtField l1 -> do
     located l1 p_ieWrappedName
     space
     txt "(..)"
     p_comma
-  IEThingWith NoExt l1 w xs _ -> sitcc $ do
+  IEThingWith NoExtField l1 w xs _ -> sitcc $ do
     located l1 p_ieWrappedName
     breakpoint
     inci $ do
@@ -91,16 +94,16 @@
             let (before, after) = splitAt n names
              in before ++ [txt ".."] ++ after
     p_comma
-  IEModuleContents NoExt l1 -> do
+  IEModuleContents NoExtField l1 -> do
     located l1 p_hsmodName
     p_comma
-  IEGroup NoExt n str -> do
+  IEGroup NoExtField n str -> do
     unless (i == 0) newline
     p_hsDocString (Asterisk n) False (noLoc str)
-  IEDoc NoExt str ->
+  IEDoc NoExtField str ->
     p_hsDocString Pipe False (noLoc str)
-  IEDocNamed NoExt str -> p_hsDocName str
-  XIE NoExt -> notImplemented "XIE"
+  IEDocNamed NoExtField str -> p_hsDocName str
+  XIE x -> noExtCon x
   where
     p_comma =
       case encLayout of
diff --git a/src/Ormolu/Printer/Meat/Module.hs b/src/Ormolu/Printer/Meat/Module.hs
--- a/src/Ormolu/Printer/Meat/Module.hs
+++ b/src/Ormolu/Printer/Meat/Module.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
 
@@ -26,10 +27,12 @@
   [Located String] ->
   -- | Pragmas
   [Pragma] ->
+  -- | Whether to use postfix qualified imports
+  Bool ->
   -- | AST to print
   ParsedSource ->
   R ()
-p_hsModule shebangs pragmas (L moduleSpan HsModule {..}) = do
+p_hsModule shebangs pragmas qualifiedPost (L moduleSpan HsModule {..}) = do
   -- 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.
@@ -63,7 +66,7 @@
         txt "where"
         newline
     newline
-    forM_ (sortImports hsmodImports) (located' p_hsmodImport)
+    forM_ (sortImports hsmodImports) (located' (p_hsmodImport qualifiedPost))
     newline
     switchLayout (getLoc <$> hsmodDecls) $ do
       p_hsDecls Free hsmodDecls
diff --git a/src/Ormolu/Printer/Meat/Type.hs b/src/Ormolu/Printer/Meat/Type.hs
--- a/src/Ormolu/Printer/Meat/Type.hs
+++ b/src/Ormolu/Printer/Meat/Type.hs
@@ -27,11 +27,11 @@
 
 p_hsType' :: Bool -> HsType GhcPs -> R ()
 p_hsType' multilineArgs = \case
-  HsForAllTy NoExt bndrs t -> do
-    p_forallBndrs p_hsTyVarBndr bndrs
+  HsForAllTy NoExtField visibility bndrs t -> do
+    p_forallBndrs visibility p_hsTyVarBndr bndrs
     interArgBreak
     p_hsType' multilineArgs (unLoc t)
-  HsQualTy NoExt qs t -> do
+  HsQualTy NoExtField qs t -> do
     located qs p_hsContext
     space
     txt "=>"
@@ -40,7 +40,7 @@
       HsQualTy {} -> p_hsTypeR (unLoc t)
       HsFunTy {} -> p_hsTypeR (unLoc t)
       _ -> located t p_hsTypeR
-  HsTyVar NoExt p n -> do
+  HsTyVar NoExtField p n -> do
     case p of
       IsPromoted -> do
         txt "'"
@@ -49,10 +49,20 @@
           _ -> return ()
       NotPromoted -> return ()
     p_rdrName n
-  HsAppTy NoExt f x -> sitcc $ do
-    located f p_hsType
-    breakpoint
-    inci (located x p_hsType)
+  HsAppTy NoExtField f x -> do
+    let -- In order to format type applications with multiple parameters
+        -- nicer, traverse the AST to gather the function and all the
+        -- parameters together.
+        gatherArgs f' knownArgs =
+          case f' of
+            L _ (HsAppTy _ l r) -> gatherArgs l (r : knownArgs)
+            _ -> (f', knownArgs)
+        (func, args) = gatherArgs f [x]
+    switchLayout (getLoc f : fmap getLoc args) $ sitcc $ do
+      located func p_hsType
+      breakpoint
+      inci $
+        sep breakpoint (located' p_hsType) args
   HsAppKindTy _ ty kd -> sitcc $ do
     -- The first argument is the location of the "@..." part. Not 100% sure,
     -- but I think we can ignore it as long as we use 'located' on both the
@@ -62,7 +72,7 @@
     inci $ do
       txt "@"
       located kd p_hsType
-  HsFunTy NoExt x y@(L _ y') -> do
+  HsFunTy NoExtField x y@(L _ y') -> do
     located x p_hsType
     space
     txt "->"
@@ -70,9 +80,9 @@
     case y' of
       HsFunTy {} -> p_hsTypeR y'
       _ -> located y p_hsTypeR
-  HsListTy NoExt t ->
+  HsListTy NoExtField t ->
     located t (brackets N . p_hsType)
-  HsTupleTy NoExt tsort xs ->
+  HsTupleTy NoExtField tsort xs ->
     let parens' =
           case tsort of
             HsUnboxedTuple -> parensHash N
@@ -81,33 +91,33 @@
             HsBoxedOrConstraintTuple -> parens N
      in parens' . sitcc $
           sep (comma >> breakpoint) (sitcc . located' p_hsType) xs
-  HsSumTy NoExt xs ->
+  HsSumTy NoExtField xs ->
     parensHash N . sitcc $
       sep (txt "|" >> breakpoint) (sitcc . located' p_hsType) xs
-  HsOpTy NoExt x op y ->
+  HsOpTy NoExtField x op y ->
     sitcc $
       let opTree = OpBranch (tyOpTree x) op (tyOpTree y)
        in p_tyOpTree (reassociateOpTree Just opTree)
-  HsParTy NoExt t ->
+  HsParTy NoExtField t ->
     parens N (located t p_hsType)
-  HsIParamTy NoExt n t -> sitcc $ do
+  HsIParamTy NoExtField n t -> sitcc $ do
     located n atom
     space
     txt "::"
     breakpoint
     inci (located t p_hsType)
-  HsStarTy NoExt _ -> txt "*"
-  HsKindSig NoExt t k -> sitcc $ do
+  HsStarTy NoExtField _ -> txt "*"
+  HsKindSig NoExtField t k -> 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
+  HsSpliceTy NoExtField splice -> p_hsSplice splice
+  HsDocTy NoExtField t str -> do
     p_hsDocString Pipe True str
     located t p_hsType
-  HsBangTy NoExt (HsSrcBang _ u s) t -> do
+  HsBangTy NoExtField (HsSrcBang _ u s) t -> do
     case u of
       SrcUnpack -> txt "{-# UNPACK #-}" >> space
       SrcNoUnpack -> txt "{-# NOUNPACK #-}" >> space
@@ -117,9 +127,9 @@
       SrcStrict -> txt "!"
       NoSrcStrict -> return ()
     located t p_hsType
-  HsRecTy NoExt fields ->
+  HsRecTy NoExtField fields ->
     p_conDeclFields fields
-  HsExplicitListTy NoExt p xs -> do
+  HsExplicitListTy NoExtField p xs -> do
     case p of
       IsPromoted -> txt "'"
       NotPromoted -> return ()
@@ -130,18 +140,18 @@
         (IsPromoted, L _ t : _) | isPromoted t -> space
         _ -> return ()
       sitcc $ sep (comma >> breakpoint) (sitcc . located' p_hsType) xs
-  HsExplicitTupleTy NoExt xs -> do
+  HsExplicitTupleTy NoExtField 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 ->
+  HsTyLit NoExtField t ->
     case t of
       HsStrTy (SourceText s) _ -> p_stringLit s
       a -> atom a
-  HsWildCardTy NoExt -> txt "_"
+  HsWildCardTy NoExtField -> txt "_"
   XHsType (NHsCoreTy t) -> atom t
   where
     isPromoted = \case
@@ -173,26 +183,29 @@
 
 p_hsTyVarBndr :: HsTyVarBndr GhcPs -> R ()
 p_hsTyVarBndr = \case
-  UserTyVar NoExt x ->
+  UserTyVar NoExtField x ->
     p_rdrName x
-  KindedTyVar NoExt l k -> parens N $ do
+  KindedTyVar NoExtField l k -> parens N $ do
     located l atom
     space
     txt "::"
     breakpoint
     inci (located k p_hsType)
-  XTyVarBndr NoExt -> notImplemented "XTyVarBndr"
+  XTyVarBndr x -> noExtCon x
 
 -- | Render several @forall@-ed variables.
-p_forallBndrs :: Data a => (a -> R ()) -> [Located a] -> R ()
-p_forallBndrs _ [] = txt "forall."
-p_forallBndrs p tyvars =
+p_forallBndrs :: Data a => ForallVisFlag -> (a -> R ()) -> [Located a] -> R ()
+p_forallBndrs ForallInvis _ [] = txt "forall."
+p_forallBndrs ForallVis _ [] = txt "forall ->"
+p_forallBndrs vis p tyvars =
   switchLayout (getLoc <$> tyvars) $ do
     txt "forall"
     breakpoint
     inci $ do
       sitcc $ sep breakpoint (sitcc . located' p) tyvars
-      txt "."
+      case vis of
+        ForallInvis -> txt "."
+        ForallVis -> space >> txt "->"
 
 p_conDeclFields :: [LConDeclField GhcPs] -> R ()
 p_conDeclFields xs =
@@ -211,10 +224,10 @@
   txt "::"
   breakpoint
   sitcc . inci $ p_hsType (unLoc cd_fld_type)
-p_conDeclField (XConDeclField NoExt) = notImplemented "XConDeclField"
+p_conDeclField (XConDeclField x) = noExtCon x
 
 tyOpTree :: LHsType GhcPs -> OpTree (LHsType GhcPs) (Located RdrName)
-tyOpTree (L _ (HsOpTy NoExt l op r)) =
+tyOpTree (L _ (HsOpTy NoExtField l op r)) =
   OpBranch (tyOpTree l) op (tyOpTree r)
 tyOpTree n = OpNode n
 
@@ -235,17 +248,17 @@
 tyVarsToTypes :: LHsQTyVars GhcPs -> [LHsType GhcPs]
 tyVarsToTypes = \case
   HsQTvs {..} -> fmap tyVarToType <$> hsq_explicit
-  XLHsQTyVars {} -> notImplemented "XLHsQTyVars"
+  XLHsQTyVars x -> noExtCon x
 
 tyVarToType :: HsTyVarBndr GhcPs -> HsType GhcPs
 tyVarToType = \case
-  UserTyVar NoExt tvar -> HsTyVar NoExt NotPromoted tvar
-  KindedTyVar NoExt tvar kind ->
+  UserTyVar NoExtField tvar -> HsTyVar NoExtField NotPromoted tvar
+  KindedTyVar NoExtField tvar kind ->
     -- Note: we always add parentheses because for whatever reason GHC does
     -- not use HsParTy for left-hand sides of declarations. Please see
     -- <https://gitlab.haskell.org/ghc/ghc/issues/17404>. This is fine as
     -- long as 'tyVarToType' does not get applied to right-hand sides of
     -- declarations.
-    HsParTy NoExt $ noLoc $
-      HsKindSig NoExt (noLoc (HsTyVar NoExt NotPromoted tvar)) kind
-  XTyVarBndr {} -> notImplemented "XTyVarBndr"
+    HsParTy NoExtField $ noLoc $
+      HsKindSig NoExtField (noLoc (HsTyVar NoExtField NotPromoted tvar)) kind
+  XTyVarBndr x -> noExtCon x
diff --git a/src/Ormolu/Printer/Operators.hs b/src/Ormolu/Printer/Operators.hs
--- a/src/Ormolu/Printer/Operators.hs
+++ b/src/Ormolu/Printer/Operators.hs
@@ -10,16 +10,13 @@
   )
 where
 
-import BasicTypes (Fixity (..), SourceText (NoSourceText), compareFixity, defaultFixity)
 import Data.Function (on)
-import Data.List
+import qualified Data.List as L
 import Data.Maybe (fromMaybe, mapMaybe)
 import Data.Ord (Down (Down), comparing)
 import GHC
 import OccName (mkVarOcc)
 import Ormolu.Utils (unSrcSpan)
-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
@@ -108,7 +105,7 @@
 buildFixityMap getOpName opTree =
   concatMap (\(i, ns) -> map (\(n, _) -> (n, fixity i InfixL)) ns)
     . zip [0 ..]
-    . groupBy (doubleWithinEps 0.00001 `on` snd)
+    . L.groupBy (doubleWithinEps 0.00001 `on` snd)
     . (overrides ++)
     . modeScores
     $ score opTree
@@ -146,22 +143,22 @@
     -- Pick the most common score per 'RdrName'.
     modeScores :: [(RdrName, Double)] -> [(RdrName, Double)]
     modeScores =
-      sortOn snd
+      L.sortOn snd
         . mapMaybe
           ( \case
               [] -> Nothing
               xs@((n, _) : _) -> Just (n, mode $ map snd xs)
           )
-        . groupBy ((==) `on` fst)
-        . sort
+        . L.groupBy ((==) `on` fst)
+        . L.sort
     -- Return the most common number, leaning to the smaller
     -- one in case of a tie.
     mode :: [Double] -> Double
     mode =
       head
-        . minimumBy (comparing (Down . length))
-        . groupBy (doubleWithinEps 0.0001)
-        . sort
+        . L.minimumBy (comparing (Down . length))
+        . L.groupBy (doubleWithinEps 0.0001)
+        . L.sort
     -- The start column of the rightmost operator.
     maxCol = go opTree
       where
diff --git a/src/Ormolu/Utils.hs b/src/Ormolu/Utils.hs
--- a/src/Ormolu/Utils.hs
+++ b/src/Ormolu/Utils.hs
@@ -22,7 +22,7 @@
 import Data.Text (Text)
 import qualified Data.Text as T
 import GHC
-import HsDoc (HsDocString, unpackHDS)
+import GHC.DynFlags (baseDynFlags)
 import qualified Outputable as GHC
 
 -- | Combine all source spans from the given list.
@@ -39,7 +39,7 @@
 
 -- | Pretty-print an 'GHC.Outputable' thing.
 showOutputable :: GHC.Outputable o => o -> String
-showOutputable = GHC.showSDocUnsafe . GHC.ppr
+showOutputable = GHC.showSDoc baseDynFlags . GHC.ppr
 
 -- | Split and normalize a doc string. The result is a list of lines that
 -- make up the comment.