diff --git a/.stylish-haskell.yaml b/.stylish-haskell.yaml new file mode 100644 --- /dev/null +++ b/.stylish-haskell.yaml @@ -0,0 +1,154 @@ +# stylish-haskell configuration file +# ================================== + +# The stylish-haskell tool is mainly configured by specifying steps. These steps +# are a list, so they have an order, and one specific step may appear more than +# once (if needed). Each file is processed by these steps in the given order. +steps: + # Convert some ASCII sequences to their Unicode equivalents. This is disabled + # by default. + # - unicode_syntax: + # # In order to make this work, we also need to insert the UnicodeSyntax + # # language pragma. If this flag is set to true, we insert it when it's + # # not already present. You may want to disable it if you configure + # # language extensions using some other method than pragmas. Default: + # # true. + # add_language_pragma: true + + # Import cleanup + - imports: + # There are different ways we can align names and lists. + # + # - global: Align the import names and import list throughout the entire + # file. + # + # - file: Like global, but don't add padding when there are no qualified + # imports in the file. + # + # - group: Only align the imports per group (a group is formed by adjacent + # import lines). + # + # - none: Do not perform any alignment. + # + # Default: global. + align: group + + # Folowing options affect only import list alignment. + # + # List align has following options: + # + # - after_alias: Import list is aligned with end of import including + # 'as' and 'hiding' keywords. + # + # > import qualified Data.List as List (concat, foldl, foldr, head, + # > init, last, length) + # + # - with_alias: Import list is aligned with start of alias or hiding. + # + # > import qualified Data.List as List (concat, foldl, foldr, head, + # > init, last, length) + # + # - new_line: Import list starts always on new line. + # + # > import qualified Data.List as List + # > (concat, foldl, foldr, head, init, last, length) + # + # Default: after alias + list_align: after_alias + + # Long list align style takes effect when import is too long. This is + # determined by 'columns' setting. + # + # - inline: This option will put as much specs on same line as possible. + # + # - new_line: Import list will start on new line. + # + # - new_line_multiline: Import list will start on new line when it's + # short enough to fit to single line. Otherwise it'll be multiline. + # + # - multiline: One line per import list entry. + # Type with contructor list acts like single import. + # + # > import qualified Data.Map as M + # > ( empty + # > , singleton + # > , ... + # > , delete + # > ) + # + # Default: inline + long_list_align: new_line_multiline + + # List padding determines indentation of import list on lines after import. + # This option affects 'list_align' and 'long_list_align'. + list_padding: 4 + + # Separate lists option affects formating of import list for type + # or class. The only difference is single space between type and list + # of constructors, selectors and class functions. + # + # - true: There is single space between Foldable type and list of it's + # functions. + # + # > import Data.Foldable (Foldable (fold, foldl, foldMap)) + # + # - false: There is no space between Foldable type and list of it's + # functions. + # + # > import Data.Foldable (Foldable(fold, foldl, foldMap)) + # + # Default: true + separate_lists: true + + # Language pragmas + - language_pragmas: + # We can generate different styles of language pragma lists. + # + # - vertical: Vertical-spaced language pragmas, one per line. + # + # - compact: A more compact style. + # + # - compact_line: Similar to compact, but wrap each line with + # `{-#LANGUAGE #-}'. + # + # Default: vertical. + style: vertical + + # Align affects alignment of closing pragma brackets. + # + # - true: Brackets are aligned in same collumn. + # + # - false: Brackets are not aligned together. There is only one space + # between actual import and closing bracket. + # + # Default: true + align: true + + # stylish-haskell can detect redundancy of some language pragmas. If this + # is set to true, it will remove those redundant pragmas. Default: true. + remove_redundant: true + + # Align the types in record declarations + # - records: {} + + # Replace tabs by spaces. This is disabled by default. + # - tabs: + # # Number of spaces to use for each tab. Default: 8, as specified by the + # # Haskell report. + # spaces: 8 + + # Remove trailing whitespace + - trailing_whitespace: {} + +# A common setting is the number of columns (parts of) code will be wrapped +# to. Different steps take this into account. Default: 80. +columns: 80 + +# Sometimes, language extensions are specified in a cabal file or from the +# command line instead of using language pragmas in the file. stylish-haskell +# needs to be aware of these, so it can parse the file correctly. +# +# No language extensions are enabled by default. +# language_extensions: + # - TemplateHaskell + # - QuasiQuotes diff --git a/README.md b/README.md new file mode 100644 --- /dev/null +++ b/README.md @@ -0,0 +1,81 @@ +Prettyprint `Show` output +========================= + +Output of nested data structures by `Show` instances is often very hard to read. +This package offers a simple function to insert line breaks and indentation into +that ouput so that the semantics are unchanged, but makes it *much* easier to +read. + +The package does not rely on a parser for actual Haskell; instead, it merely +reacts on parentheses, commas and the like. This makes it fairly robust even in +the face of invalid `Show` instances, that may not produce valid Haskell code. + + + +## Examples + +### Artificial + +```haskell +Hello Foo ("(Bar", Haha) (Baz (A { foo = C, bar = D, qux = (E,"He)llo World!",G, + H,[A,B,c,d,e,Fghi]) } ) (B,C) [Baz A1 B2, (Baz A3 (B4)), (Baz A5 (B6)), (Baz + (A7) B8)]) (Foo) (Bar) (Baz (A) (B)) + +==> + +Hello Foo ("(Bar",Haha) + (Baz (A {foo = C + ,bar = D + ,qux = (E + ,"He)llo World!" + ,G + ,H + ,[A,B,c,d,e,Fghi])}) + (B,C) + [Baz A1 B2 + ,(Baz A3 (B4)) + ,(Baz A5 (B6)) + ,(Baz (A7) B8)]) + (Foo) + (Bar) + (Baz (A) (B)) +``` + +### Inspired by a real AST + +```haskell +Set (fromList [(Name "A string with (parenthesis",Ann (Entry (Quality 1 1) + (Ann False) (Ann (Map [Ann (Bound (Ann (Id "lorem"))),Ann (Variable + (Ann (Id "ipsum")))])))),(Name "string",Ann (Entry (Quality 1 1) (Ann + True) (Ann (Internal (Ann (Reduce (Ann (Id "dolor")) (Ann (Id "sit"))))) + ))),(Name "Another } here",Ann (Entry (Quality 1 1) (Ann (Or [Ann (Not + (Ann (Is (Ann Flagged) (Ann Type) (Ann (Multi [Ann (Literal (Ann One)) + ]))))),Ann (Is (Ann Flagged) (Ann Type) (Ann (Multi [Ann (Literal (Ann + Three))]))),Ann (Is (Ann Flagged) (Ann Type) (Ann (Multi [Ann (Literal + (Ann Two))])))])) (Ann (Internal (Ann (Concat (Ann (Id "amet"))))))))]) + +==> + +Set (fromList [(Name "A string with (parenthesis" + ,Ann (Entry (Quality 1 1) + (Ann False) + (Ann (Map [Ann (Bound (Ann (Id "lorem"))) + ,Ann (Variable (Ann (Id "ipsum")))])))) + ,(Name "string" + ,Ann (Entry (Quality 1 1) + (Ann True) + (Ann (Internal (Ann (Reduce (Ann (Id "dolor")) + (Ann (Id "sit")))))))) + ,(Name "Another } here" + ,Ann (Entry (Quality 1 1) + (Ann (Or [Ann (Not (Ann (Is (Ann Flagged) + (Ann Type) + (Ann (Multi [Ann (Literal (Ann One))]))))) + ,Ann (Is (Ann Flagged) + (Ann Type) + (Ann (Multi [Ann (Literal (Ann Three))]))) + ,Ann (Is (Ann Flagged) + (Ann Type) + (Ann (Multi [Ann (Literal (Ann Two))])))])) + (Ann (Internal (Ann (Concat (Ann (Id "amet"))))))))]) +``` diff --git a/show-prettyprint.cabal b/show-prettyprint.cabal --- a/show-prettyprint.cabal +++ b/show-prettyprint.cabal @@ -1,5 +1,5 @@ name: show-prettyprint -version: 0.1.0.0 +version: 0.1.0.1 synopsis: Robust prettyprinter for output of auto-generated Show instances description: See README.md @@ -11,7 +11,8 @@ copyright: David Luposchainsky, 2016 category: User Interfaces, Text build-type: Simple --- extra-source-files: +extra-source-files: README.md + , .stylish-haskell.yaml cabal-version: >=1.10 library