.stylish-haskell.yaml

# stylish-haskell configuration file
# based on:
# https://www.parsonsmatt.org/2020/03/17/gradual_import_style_improvements.html
# ==================================

# 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

  # Align the right hand side of some elements.  This is quite conservative
  # and only applies to statements where each element occupies a single
  # line.
  - simple_align:
      cases: false
      top_level_patterns: false
      records: false

  # 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: none

      # 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)
      #
      # - 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: with_module_name

      # 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: false

      # 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: new_line_multiline

      # 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.
      list_padding: 7 # length of "import "

      # 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: false

      # 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

  # 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 column.
      #
      # - false: Brackets are not aligned together. There is only one space
      #   between actual import and closing bracket.
      #
      # Default: true
      align: false

      # 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: false

  # 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. 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: lf

# 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