feat(nix/haskell): add stylish-haskell formatter

.gitignore

@@ -27,3 +27,8 @@
 !/programs/xmonad
 /programs/xmonad/*
 !/programs/xmonad/*.hs
+
+!/programs/stylish-haskell
+/programs/stylish-haskell/*
+!/programs/stylish-haskell/config.yml
+

nix/home.nix

@@ -41,16 +41,23 @@ in
   home.stateVersion = "21.11";
 
   home.packages = with pkgs; [
+    # system ui
     dmenu           # menu for x window system
     xmobar          # a minimalistic text based status bar
     flameshot       # powerful yet simple to use screenshot software
 
+    # tools
     xh              # friendly and fast tool for sending HTTP requests
     fd              # a simple, fast and user-friendly alternative to find
     bat             # a cat clone with syntax highlighting and git integration
 
+    # haskell
+    stylish-haskell # formatter
+
+    # database
     postgresql_12   # 🤷 I need only psql
 
+    # browser
     librewolf       # a fork of firefox, focused on privacy, security and freedom
   ];
 
@@ -165,7 +172,7 @@ in
     # add config for xmonad window manager
     # "xmonad/xmonad.hs".source = ../programs/xmonad/xmonad.hs;
     # "xmobar/xmobar.hs".source = ../programs/xmonad/xmobar.hs;
+
+    "stylish-haskell/config.yaml".source = ../programs/stylish-haskell/config.yml;
   };
-
-
 }

programs/stylish-haskell/config.yml

@@ -0,0 +1,380 @@
+# 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
+
+  # Format module header
+  #
+  # Currently, this option is not configurable and will format all exports and
+  # module declarations to minimize diffs
+  #
+  # - module_header:
+  #     # How many spaces use for indentation in the module header.
+  #     indent: 4
+  #
+  #     # Should export lists be sorted?  Sorting is only performed within the
+  #     # export section, as delineated by Haddock comments.
+  #     sort: true
+  #
+  #     # See `separate_lists` for the `imports` step.
+  #     separate_lists: true
+  #
+  #     # When to break the "where".
+  #     # Possible values:
+  #     # - exports: only break when there is an explicit export list.
+  #     # - single: only break when the export list counts more than one export.
+  #     # - inline: only break when the export list is too long. This is
+  #     #   determined by the `columns` setting. Not applicable when the export
+  #     #   list contains comments as newlines will be required.
+  #     # - always: always break before the "where".
+  #     break_where: exports
+  #
+  #     # Where to put open bracket
+  #     # Possible values:
+  #     # - same_line: put open bracket on the same line as the module name, before the
+  #     #              comment of the module
+  #     # - next_line: put open bracket on the next line, after module comment
+  #     open_bracket: next_line
+
+  # Format record definitions. This is disabled by default.
+  #
+  # You can control the layout of record fields. The only rules that can't be configured
+  # are these:
+  #
+  # - "|" is always aligned with "="
+  # - "," in fields is always aligned with "{"
+  # - "}" is likewise always aligned with "{"
+  #
+  # - records:
+  #     # How to format equals sign between type constructor and data constructor.
+  #     # Possible values:
+  #     # - "same_line" -- leave "=" AND data constructor on the same line as the type constructor.
+  #     # - "indent N" -- insert a new line and N spaces from the beginning of the next line.
+  #     equals: "indent 2"
+  #
+  #     # How to format first field of each record constructor.
+  #     # Possible values:
+  #     # - "same_line" -- "{" and first field goes on the same line as the data constructor.
+  #     # - "indent N" -- insert a new line and N spaces from the beginning of the data constructor
+  #     first_field: "indent 2"
+  #
+  #     # How many spaces to insert between the column with "," and the beginning of the comment in the next line.
+  #     field_comment: 2
+  #
+  #     # How many spaces to insert before "deriving" clause. Deriving clauses are always on separate lines.
+  #     deriving: 2
+  #
+  #     # How many spaces to insert before "via" clause counted from indentation of deriving clause
+  #     # Possible values:
+  #     # - "same_line" -- "via" part goes on the same line as "deriving" keyword.
+  #     # - "indent N" -- insert a new line and N spaces from the beginning of "deriving" keyword.
+  #     via: "indent 2"
+  #
+  #     # Sort typeclass names in the "deriving" list alphabetically.
+  #     sort_deriving: true
+  #
+  #     # Wheter or not to break enums onto several lines
+  #     #
+  #     # Default: false
+  #     break_enums: false
+  #
+  #     # Whether or not to break single constructor data types before `=` sign
+  #     #
+  #     # Default: true
+  #     break_single_constructors: true
+  #
+  #     # Whether or not to curry constraints on function.
+  #     #
+  #     # E.g: @allValues :: Enum a => Bounded a => Proxy a -> [a]@
+  #     #
+  #     # Instead of @allValues :: (Enum a, Bounded a) => Proxy a -> [a]@
+  #     #
+  #     # Default: false
+  #     curried_context: false
+
+  # Align the right hand side of some elements.  This is quite conservative
+  # and only applies to statements where each element occupies a single
+  # line.
+  # Possible values:
+  # - always - Always align statements.
+  # - adjacent - Align statements that are on adjacent lines in groups.
+  # - never - Never align statements.
+  # All default to always.
+  - simple_align:
+      cases: always
+      top_level_patterns: always
+      records: always
+      multi_way_if: always
+
+  # 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: global
+
+      # The following 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)
+      #
+      # - with_module_name: Import list is aligned `list_padding` spaces after
+      #   the module name.
+      #
+      #   > import qualified Data.List      as List (concat, foldl, foldr, head,
+      #                          init, last, length)
+      #
+      #   This is mainly intended for use with `pad_module_names: false`.
+      #
+      #   > import qualified Data.List as List (concat, foldl, foldr, head,
+      #                          init, last, length, scanl, scanr, take, drop,
+      #                          sort, nub)
+      #
+      # - new_line: Import list starts always on new line.
+      #
+      #   > import qualified Data.List      as List
+      #   >     (concat, foldl, foldr, head, init, last, length)
+      #
+      # - repeat: Repeat the module name to align the import list.
+      #
+      #   > import qualified Data.List      as List (concat, foldl, foldr, head)
+      #   > import qualified Data.List      as List (init, last, length)
+      #
+      # Default: after_alias
+      list_align: after_alias
+
+      # Right-pad the module names to align imports in a group:
+      #
+      # - true: a little more readable
+      #
+      #   > import qualified Data.List       as List (concat, foldl, foldr,
+      #   >                                           init, last, length)
+      #   > import qualified Data.List.Extra as List (concat, foldl, foldr,
+      #   >                                           init, last, length)
+      #
+      # - false: diff-safe
+      #
+      #   > import qualified Data.List as List (concat, foldl, foldr, init,
+      #   >                                     last, length)
+      #   > import qualified Data.List.Extra as List (concat, foldl, foldr,
+      #   >                                           init, last, length)
+      #
+      # Default: true
+      pad_module_names: true
+
+      # 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 constructor list acts like single import.
+      #
+      #   > import qualified Data.Map as M
+      #   >     ( empty
+      #   >     , singleton
+      #   >     , ...
+      #   >     , delete
+      #   >     )
+      #
+      # Default: inline
+      long_list_align: inline
+
+      # Align empty list (importing instances)
+      #
+      # Empty list align has following options
+      #
+      # - inherit: inherit list_align setting
+      #
+      # - right_after: () is right after the module name:
+      #
+      #   > import Vector.Instances ()
+      #
+      # Default: inherit
+      empty_list_align: inherit
+
+      # List padding determines indentation of import list on lines after import.
+      # This option affects 'long_list_align'.
+      #
+      # - <integer>: constant value
+      #
+      # - module_name: align under start of module name.
+      #   Useful for 'file' and 'group' align settings.
+      #
+      # Default: 4
+      list_padding: 4
+
+      # Separate lists option affects formatting 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
+
+      # Space surround option affects formatting of import lists on a single
+      # line. The only difference is single space after the initial
+      # parenthesis and a single space before the terminal parenthesis.
+      #
+      # - true: There is single space associated with the enclosing
+      #   parenthesis.
+      #
+      #   > import Data.Foo ( foo )
+      #
+      # - false: There is no space associated with the enclosing parenthesis
+      #
+      #   > import Data.Foo (foo)
+      #
+      # Default: false
+      space_surround: false
+
+      # Post qualify option moves any qualifies found in import declarations
+      # to the end of the declaration. This also adjust padding for any
+      # unqualified import declarations.
+      #
+      # - true: Qualified as <module name> is moved to the end of the
+      #   declaration.
+      #
+      #   > import Data.Bar
+      #   > import Data.Foo qualified as F
+      #
+      # - false: Qualified remains in the default location and unqualified
+      #   imports are padded to align with qualified imports.
+      #
+      #   > import           Data.Bar
+      #   > import qualified Data.Foo as F
+      #
+      # Default: false
+      post_qualify: false
+
+
+  # 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 #-}'.
+      #
+      # - vertical_compact: Similar to vertical, but use only one language pragma.
+      #
+      # Default: vertical.
+      style: vertical
+
+      # Align affects alignment of closing pragma brackets.
+      #
+      # - true: Brackets are aligned in same column.
+      #
+      # - 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
+
+      # Language prefix to be used for pragma declaration, this allows you to
+      # use other options non case-sensitive like "language" or "Language".
+      # If a non correct String is provided, it will default to: LANGUAGE.
+      language_prefix: LANGUAGE
+
+  # 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: {}
+
+  # Squash multiple spaces between the left and right hand sides of some
+  # elements into single spaces. Basically, this undoes the effect of
+  # simple_align but is a bit less conservative.
+  # - squash: {}
+
+# A common setting is the number of columns (parts of) code will be wrapped
+# to. Different steps take this into account.
+#
+# Set this to null to disable all line wrapping.
+#
+# Default: 80.
+columns: 80
+
+# By default, line endings are converted according to the OS. You can override
+# preferred format here.
+#
+# - native: Native newline format. CRLF on Windows, LF on other OSes.
+#
+# - lf: Convert to LF ("\n").
+#
+# - crlf: Convert to CRLF ("\r\n").
+#
+# Default: native.
+newline: native
+
+# 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
+
+# Attempt to find the cabal file in ancestors of the current directory, and
+# parse options (currently only language extensions) from that.
+#
+# Default: true
+cabal: true