changed string representation to \abx -> x

pcp/.stylish-haskell.yaml

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

pcp/pcp.hs

@@ -43,23 +43,23 @@ second = \p -> p (\x -> \y -> y)
 
 -- STRINGS
 
-type LCStrT = forall a . a -> (a -> a) -> (a -> a) -> a
+type LCStrT = forall a . (a -> a) -> (a -> a) -> a -> a
 newtype LCStr = LCStr { unString :: LCStrT }
 
 empty :: LCStr
-empty = LCStr $ \x a b -> x
+empty = LCStr $ \a b x -> x
 
 isempty :: LCStr -> LCBool
-isempty = \s -> unString s true af af
+isempty = \s -> unString s af af true
 
 conc :: LCStr -> LCStr -> LCStr
-conc = \y z -> LCStr $ \x a b -> unString y (unString z x a b) a b
+conc = \y z -> LCStr $ \a b x -> unString y a b (unString z a b x)
 
 prepa :: LCStr -> LCStr
-prepa = \s -> LCStr $ \x a b -> a (unString s x a b)
+prepa = \s -> LCStr $ \a b x -> a (unString s a b x)
 
 prepb :: LCStr -> LCStr
-prepb = \s -> LCStr $ \x a b -> b (unString s x a b)
+prepb = \s -> LCStr $ \a b x -> b (unString s a b x)
 
 nexta :: LCPair LCStr -> LCPair LCStr
 nexta = \x -> pair (prepa (first x)) (first x)
@@ -68,19 +68,19 @@ nextb :: LCPair LCStr -> LCPair LCStr
 nextb = \x -> pair (prepb (first x)) (first x)
 
 hd_a :: LCStr -> LCBool
-hd_a = \s -> unString s false at af
+hd_a = \s -> unString s at af false
 
 hd_b :: LCStr -> LCBool
-hd_b = \s -> unString s false af at
+hd_b = \s -> unString s af at false
 
 hd_eq :: LCStr -> LCStr -> LCBool
 hd_eq = \x y -> lor (land (hd_a x) (hd_a y)) (land (hd_b x) (hd_b y))
 
 hd :: LCStr -> LCStr
-hd = \s -> LCStr $ \x a b -> unString s x (\y -> a x) (\y -> b x)
+hd = \s -> LCStr $ \a b x -> unString s (\y -> a x) (\y -> b x) x
 
 tl :: LCStr -> LCStr
-tl = \s -> second (unString s (pair empty empty) nexta nextb)
+tl = \s -> second (unString s nexta nextb (pair empty empty))
 
 eq :: LCStr -> LCStr -> LCBool
 eq = ycomb (\f x y ->
@@ -94,34 +94,34 @@ prefix = ycomb (\f x y -> ite (isempty x) true (land (hd_eq x y) (f (tl x) (tl y
 -- SOME STRINGS
 
 a :: LCStr
-a = LCStr $ \x a b -> a x
+a = LCStr $ \a b x -> a x
 
 b :: LCStr
-b = LCStr $ \x a b -> b x
+b = LCStr $ \a b x -> b x
 
 ab :: LCStr
-ab = LCStr $ \x a b -> a (b x)
+ab = LCStr $ \a b x -> a (b x)
 
 ba :: LCStr
-ba = LCStr $ \x a b -> b (a x)
+ba = LCStr $ \a b x -> b (a x)
 
 bb :: LCStr
-bb = LCStr $ \x a b -> b (b x)
+bb = LCStr $ \a b x -> b (b x)
 
 bba :: LCStr
-bba = LCStr $ \x a b -> b (b (a x))
+bba = LCStr $ \a b x -> b (b (a x))
 
 abb :: LCStr
-abb = LCStr $ \x a b -> a (b (b x))
+abb = LCStr $ \a b x -> a (b (b x))
 
 abba :: LCStr
-abba = LCStr $ \x a b -> a (b (b (a x)))
+abba = LCStr $ \a b x -> a (b (b (a x)))
 
 abbb :: LCStr
-abbb = LCStr $ \x a b -> a (b (b (b x)))
+abbb = LCStr $ \a b x -> a (b (b (b x)))
 
 baba :: LCStr
-baba = LCStr $ \x a b -> b (a (b (a x)))
+baba = LCStr $ \a b x -> b (a (b (a x)))
 
 -- RECURSION
 
@@ -198,7 +198,7 @@ problem_3 = cons (pair bba b) (cons (pair b ab) (cons (pair a bba) nil))
 -- Output functions
 
 lcstr_tostr :: LCStr -> String
-lcstr_tostr = \s -> unString s ("") (\a -> "a" ++ a) (\b -> "b" ++ b)
+lcstr_tostr = \s -> unString s (\a -> "a" ++ a) (\b -> "b" ++ b) ("")
 
 lcbool_tostr :: LCBool -> String
 lcbool_tostr = \b -> ite b "True" "False"