    {-# LANGUAGE CPP #-}
    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Text.PrettyPrint.ANSI.Leijen.Internal
    -- Copyright   :  Daan Leijen (c) 2000, http://www.cs.uu.nl/~daan
    --                Max Bolingbroke (c) 2008, http://blog.omega-prime.co.uk
    -- License     :  BSD-style (see the file LICENSE)
    --
    -- Maintainer  :  Edward Kmett <ekmett@gmail.com>
    -- Stability   :  provisional
    -- Portability :  portable
    --
    --
    -- __WARNING:__ Internal module. The contents of this file may vary arbitrarily
    -- between any two versions. Use the public API if you care about stability.
    module Text.PrettyPrint.ANSI.Leijen.Internal where

    import System.IO (Handle,hPutStr,hPutChar,stdout)

    import System.Console.ANSI (Color(..), ColorIntensity(..), ConsoleLayer(..),
                                Underlining(..), ConsoleIntensity(..),
                                SGR(..), hSetSGR, setSGRCode)

    import Data.String (IsString(..))
    import Data.Maybe (catMaybes)

    -- NB: if you import more from Data.Semigroup make sure the
    --     build-depends version range is still accurate
    -- NB2: if you consider re-exporting Semigroup((<>)) take into account
    --      that only starting with semigroup-0.8 `infixr 6 <>` was used!
    import qualified Data.Semigroup as Semi (Semigroup((<>)))

    #if __GLASGOW_HASKELL__ >= 710
    import Data.Monoid ((<>))
    #elif __GLASGOW_HASKELL__ >= 704
    import Data.Monoid (Monoid, mappend, mconcat, mempty, (<>))
    #else
    import Data.Monoid (Monoid, mappend, mconcat, mempty)
    infixr 6 <>
    #endif

    infixr 6 <+>
    infixr 5 </>,<//>,<$>,<$$>

    -----------------------------------------------------------
    -- list, tupled and semiBraces pretty print a list of
    -- documents either horizontally or vertically aligned.
    -----------------------------------------------------------

    -- | The document @(list xs)@ comma separates the documents @xs@ and
    -- encloses them in square brackets. The documents are rendered
    -- horizontally if that fits the page. Otherwise they are aligned
    -- vertically. All comma separators are put in front of the elements.
    list :: [Doc] -> Doc
    list :: [Doc] -> Doc
    list            = Doc -> Doc -> Doc -> [Doc] -> Doc
    encloseSep Doc
    lbracket Doc
    rbracket Doc
    comma

    -- | The document @(tupled xs)@ comma separates the documents @xs@ and
    -- encloses them in parenthesis. The documents are rendered
    -- horizontally if that fits the page. Otherwise they are aligned
    -- vertically. All comma separators are put in front of the elements.
    tupled :: [Doc] -> Doc
    tupled :: [Doc] -> Doc
    tupled          = Doc -> Doc -> Doc -> [Doc] -> Doc
    encloseSep Doc
    lparen   Doc
    rparen  Doc
    comma

    -- | The document @(semiBraces xs)@ separates the documents @xs@ with
    -- semicolons and encloses them in braces. The documents are rendered
    -- horizontally if that fits the page. Otherwise they are aligned
    -- vertically. All semicolons are put in front of the elements.
    semiBraces :: [Doc] -> Doc
    semiBraces :: [Doc] -> Doc
    semiBraces      = Doc -> Doc -> Doc -> [Doc] -> Doc
    encloseSep Doc
    lbrace   Doc
    rbrace  Doc
    semi

    -- | The document @(encloseSep l r sep xs)@ concatenates the documents
    -- @xs@ separated by @sep@ and encloses the resulting document by @l@
    -- and @r@. The documents are rendered horizontally if that fits the
    -- page. Otherwise they are aligned vertically. All separators are put
    -- in front of the elements. For example, the combinator 'list' can be
    -- defined with @encloseSep@:
    --
    -- > list xs = encloseSep lbracket rbracket comma xs
    -- > test    = text "list" <+> (list (map int [10,200,3000]))
    --
    -- Which is layed out with a page width of 20 as:
    --
    -- @
    -- list [10,200,3000]
    -- @
    --
    -- But when the page width is 15, it is layed out as:
    --
    -- @
    -- list [10
    --      ,200
    --      ,3000]
    -- @
    encloseSep :: Doc -> Doc -> Doc -> [Doc] -> Doc
    encloseSep :: Doc -> Doc -> Doc -> [Doc] -> Doc
    encloseSep Doc
    left Doc
    right Doc
    sep [Doc]
    ds
        = case [Doc]
    ds of
            []  -> Doc
    left Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    right
            [Doc
    d] -> Doc
    left Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    d Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    right
            [Doc]
    _   -> Doc -> Doc
    align ([Doc] -> Doc
    cat ((Doc -> Doc -> Doc) -> [Doc] -> [Doc] -> [Doc]
    forall a b c. (a -> b -> c) -> [a] -> [b] -> [c]
    zipWith Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    (<>) (Doc
    left Doc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    : Doc -> [Doc]
    forall a. a -> [a]
    repeat Doc
    sep) [Doc]
    ds) Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    right)

    -----------------------------------------------------------
    -- punctuate p [d1,d2,...,dn] => [d1 <> p,d2 <> p, ... ,dn]
    -----------------------------------------------------------

    -- | @(punctuate p xs)@ concatenates all documents in @xs@ with
    -- document @p@ except for the last document.
    --
    -- > someText = map text ["words","in","a","tuple"]
    -- > test     = parens (align (cat (punctuate comma someText)))
    --
    -- This is layed out on a page width of 20 as:
    --
    -- @
    -- (words,in,a,tuple)
    -- @
    --
    -- But when the page width is 15, it is layed out as:
    --
    -- @
    -- (words,
    --  in,
    --  a,
    --  tuple)
    -- @
    --
    -- (If you want put the commas in front of their elements instead of
    -- at the end, you should use 'tupled' or, in general, 'encloseSep'.)
    punctuate :: Doc -> [Doc] -> [Doc]
    punctuate :: Doc -> [Doc] -> [Doc]
    punctuate Doc
    p []      = []
    punctuate Doc
    p [Doc
    d]     = [Doc
    d]
    punctuate Doc
    p (Doc
    d:[Doc]
    ds)  = (Doc
    d Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    p) Doc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    : Doc -> [Doc] -> [Doc]
    punctuate Doc
    p [Doc]
    ds

    -----------------------------------------------------------
    -- high-level combinators
    -----------------------------------------------------------

    -- | The document @(sep xs)@ concatenates all documents @xs@ either
    -- horizontally with @(\<+\>)@, if it fits the page, or vertically with
    -- @(\<$\>)@.
    --
    -- > sep xs  = group (vsep xs)
    sep :: [Doc] -> Doc
    sep :: [Doc] -> Doc
    sep             = Doc -> Doc
    group (Doc -> Doc) -> ([Doc] -> Doc) -> [Doc] -> Doc
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . [Doc] -> Doc
    vsep

    -- | The document @(fillSep xs)@ concatenates documents @xs@
    -- horizontally with @(\<+\>)@ as long as its fits the page, than
    -- inserts a @line@ and continues doing that for all documents in
    -- @xs@.
    --
    -- > fillSep xs  = foldr (</>) empty xs
    fillSep :: [Doc] -> Doc
    fillSep :: [Doc] -> Doc
    fillSep         = (Doc -> Doc -> Doc) -> [Doc] -> Doc
    fold Doc -> Doc -> Doc
    (</>)

    -- | The document @(hsep xs)@ concatenates all documents @xs@
    -- horizontally with @(\<+\>)@.
    hsep :: [Doc] -> Doc
    hsep :: [Doc] -> Doc
    hsep            = (Doc -> Doc -> Doc) -> [Doc] -> Doc
    fold Doc -> Doc -> Doc
    (<+>)

    -- | The document @(vsep xs)@ concatenates all documents @xs@
    -- vertically with @(\<$\>)@. If a 'group' undoes the line breaks
    -- inserted by @vsep@, all documents are separated with a space.
    --
    -- > someText = map text (words ("text to lay out"))
    -- >
    -- > test     = text "some" <+> vsep someText
    --
    -- This is layed out as:
    --
    -- @
    -- some text
    -- to
    -- lay
    -- out
    -- @
    --
    -- The 'align' combinator can be used to align the documents under
    -- their first element
    --
    -- > test     = text "some" <+> align (vsep someText)
    --
    -- Which is printed as:
    --
    -- @
    -- some text
    --      to
    --      lay
    --      out
    -- @
    vsep :: [Doc] -> Doc
    vsep :: [Doc] -> Doc
    vsep            = (Doc -> Doc -> Doc) -> [Doc] -> Doc
    fold Doc -> Doc -> Doc
    (Text.PrettyPrint.ANSI.Leijen.Internal.<$>)

    -- | The document @(cat xs)@ concatenates all documents @xs@ either
    -- horizontally with @(\<\>)@, if it fits the page, or vertically with
    -- @(\<$$\>)@.
    --
    -- > cat xs  = group (vcat xs)
    cat :: [Doc] -> Doc
    cat :: [Doc] -> Doc
    cat             = Doc -> Doc
    group (Doc -> Doc) -> ([Doc] -> Doc) -> [Doc] -> Doc
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . [Doc] -> Doc
    vcat

    -- | The document @(fillCat xs)@ concatenates documents @xs@
    -- horizontally with @(\<\>)@ as long as its fits the page, than inserts
    -- a @linebreak@ and continues doing that for all documents in @xs@.
    --
    -- > fillCat xs  = foldr (<//>) empty xs
    fillCat :: [Doc] -> Doc
    fillCat :: [Doc] -> Doc
    fillCat         = (Doc -> Doc -> Doc) -> [Doc] -> Doc
    fold Doc -> Doc -> Doc
    (<//>)

    -- | The document @(hcat xs)@ concatenates all documents @xs@
    -- horizontally with @(\<\>)@.
    hcat :: [Doc] -> Doc
    hcat :: [Doc] -> Doc
    hcat            = (Doc -> Doc -> Doc) -> [Doc] -> Doc
    fold Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    (<>)

    -- | The document @(vcat xs)@ concatenates all documents @xs@
    -- vertically with @(\<$$\>)@. If a 'group' undoes the line breaks
    -- inserted by @vcat@, all documents are directly concatenated.
    vcat :: [Doc] -> Doc
    vcat :: [Doc] -> Doc
    vcat            = (Doc -> Doc -> Doc) -> [Doc] -> Doc
    fold Doc -> Doc -> Doc
    (<$$>)

    fold :: (Doc -> Doc -> Doc) -> [Doc] -> Doc
    fold :: (Doc -> Doc -> Doc) -> [Doc] -> Doc
    fold Doc -> Doc -> Doc
    f []       = Doc
    empty
    fold Doc -> Doc -> Doc
    f [Doc]
    ds       = (Doc -> Doc -> Doc) -> [Doc] -> Doc
    forall a. (a -> a -> a) -> [a] -> a
    forall (t :: * -> *) a. Foldable t => (a -> a -> a) -> t a -> a
    foldr1 Doc -> Doc -> Doc
    f [Doc]
    ds

    #if __GLASGOW_HASKELL__ < 704
    -- | The document @(x \<\> y)@ concatenates document @x@ and document
    -- @y@. It is an associative operation having 'empty' as a left and
    -- right unit.  (infixr 6)
    (<>) :: Doc -> Doc -> Doc
    x <> y          = x `beside` y
    #endif

    -- | The document @(x \<+\> y)@ concatenates document @x@ and @y@ with a
    -- @space@ in between.  (infixr 6)
    (<+>) :: Doc -> Doc -> Doc
    Doc
    x <+> :: Doc -> Doc -> Doc
    <+> Doc
    y         = Doc
    x Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    space Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    y

    -- | The document @(x \<\/\> y)@ concatenates document @x@ and @y@ with a
    -- 'softline' in between. This effectively puts @x@ and @y@ either
    -- next to each other (with a @space@ in between) or underneath each
    -- other. (infixr 5)
    (</>) :: Doc -> Doc -> Doc
    Doc
    x </> :: Doc -> Doc -> Doc
    </> Doc
    y         = Doc
    x Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    softline Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    y

    -- | The document @(x \<\/\/\> y)@ concatenates document @x@ and @y@ with
    -- a 'softbreak' in between. This effectively puts @x@ and @y@ either
    -- right next to each other or underneath each other. (infixr 5)
    (<//>) :: Doc -> Doc -> Doc
    Doc
    x <//> :: Doc -> Doc -> Doc
    <//> Doc
    y        = Doc
    x Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    softbreak Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    y

    -- | The document @(x \<$\> y)@ concatenates document @x@ and @y@ with a
    -- 'line' in between. (infixr 5)
    (<$>) :: Doc -> Doc -> Doc
    Doc
    x <$> :: Doc -> Doc -> Doc
    <$> Doc
    y         = Doc
    x Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    line Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    y

    -- | The document @(x \<$$\> y)@ concatenates document @x@ and @y@ with
    -- a @linebreak@ in between. (infixr 5)
    (<$$>) :: Doc -> Doc -> Doc
    Doc
    x <$$> :: Doc -> Doc -> Doc
    <$$> Doc
    y        = Doc
    x Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    linebreak Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    y

    -- | The document @softline@ behaves like 'space' if the resulting
    -- output fits the page, otherwise it behaves like 'line'.
    --
    -- > softline = group line
    softline :: Doc
    softline :: Doc
    softline        = Doc -> Doc
    group Doc
    line

    -- | The document @softbreak@ behaves like 'empty' if the resulting
    -- output fits the page, otherwise it behaves like 'line'.
    --
    -- > softbreak  = group linebreak
    softbreak :: Doc
    softbreak :: Doc
    softbreak       = Doc -> Doc
    group Doc
    linebreak

    -- | Document @(squotes x)@ encloses document @x@ with single quotes
    -- \"'\".
    squotes :: Doc -> Doc
    squotes :: Doc -> Doc
    squotes         = Doc -> Doc -> Doc -> Doc
    enclose Doc
    squote Doc
    squote

    -- | Document @(dquotes x)@ encloses document @x@ with double quotes
    -- '\"'.
    dquotes :: Doc -> Doc
    dquotes :: Doc -> Doc
    dquotes         = Doc -> Doc -> Doc -> Doc
    enclose Doc
    dquote Doc
    dquote

    -- | Document @(braces x)@ encloses document @x@ in braces, \"{\" and
    -- \"}\".
    braces :: Doc -> Doc
    braces :: Doc -> Doc
    braces          = Doc -> Doc -> Doc -> Doc
    enclose Doc
    lbrace Doc
    rbrace

    -- | Document @(parens x)@ encloses document @x@ in parenthesis, \"(\"
    -- and \")\".
    parens :: Doc -> Doc
    parens :: Doc -> Doc
    parens          = Doc -> Doc -> Doc -> Doc
    enclose Doc
    lparen Doc
    rparen

    -- | Document @(angles x)@ encloses document @x@ in angles, \"\<\" and
    -- \"\>\".
    angles :: Doc -> Doc
    angles :: Doc -> Doc
    angles          = Doc -> Doc -> Doc -> Doc
    enclose Doc
    langle Doc
    rangle

    -- | Document @(brackets x)@ encloses document @x@ in square brackets,
    -- \"[\" and \"]\".
    brackets :: Doc -> Doc
    brackets :: Doc -> Doc
    brackets        = Doc -> Doc -> Doc -> Doc
    enclose Doc
    lbracket Doc
    rbracket

    -- | The document @(enclose l r x)@ encloses document @x@ between
    -- documents @l@ and @r@ using @(\<\>)@.
    --
    -- > enclose l r x   = l <> x <> r
    enclose :: Doc -> Doc -> Doc -> Doc
    enclose :: Doc -> Doc -> Doc -> Doc
    enclose Doc
    l Doc
    r Doc
    x   = Doc
    l Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    x Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    r

    -- | The document @lparen@ contains a left parenthesis, \"(\".
    lparen :: Doc
    lparen :: Doc
    lparen          = Char -> Doc
    char Char
    '('
    -- | The document @rparen@ contains a right parenthesis, \")\".
    rparen :: Doc
    rparen :: Doc
    rparen          = Char -> Doc
    char Char
    ')'
    -- | The document @langle@ contains a left angle, \"\<\".
    langle :: Doc
    langle :: Doc
    langle          = Char -> Doc
    char Char
    '<'
    -- | The document @rangle@ contains a right angle, \">\".
    rangle :: Doc
    rangle :: Doc
    rangle          = Char -> Doc
    char Char
    '>'
    -- | The document @lbrace@ contains a left brace, \"{\".
    lbrace :: Doc
    lbrace :: Doc
    lbrace          = Char -> Doc
    char Char
    '{'
    -- | The document @rbrace@ contains a right brace, \"}\".
    rbrace :: Doc
    rbrace :: Doc
    rbrace          = Char -> Doc
    char Char
    '}'
    -- | The document @lbracket@ contains a left square bracket, \"[\".
    lbracket :: Doc
    lbracket :: Doc
    lbracket        = Char -> Doc
    char Char
    '['
    -- | The document @rbracket@ contains a right square bracket, \"]\".
    rbracket :: Doc
    rbracket :: Doc
    rbracket        = Char -> Doc
    char Char
    ']'

    -- | The document @squote@ contains a single quote, \"'\".
    squote :: Doc
    squote :: Doc
    squote          = Char -> Doc
    char Char
    '\''
    -- | The document @dquote@ contains a double quote, '\"'.
    dquote :: Doc
    dquote :: Doc
    dquote          = Char -> Doc
    char Char
    '"'
    -- | The document @semi@ contains a semicolon, \";\".
    semi :: Doc
    semi :: Doc
    semi            = Char -> Doc
    char Char
    ';'
    -- | The document @colon@ contains a colon, \":\".
    colon :: Doc
    colon :: Doc
    colon           = Char -> Doc
    char Char
    ':'
    -- | The document @comma@ contains a comma, \",\".
    comma :: Doc
    comma :: Doc
    comma           = Char -> Doc
    char Char
    ','
    -- | The document @space@ contains a single space, \" \".
    --
    -- > x <+> y   = x <> space <> y
    space :: Doc
    space :: Doc
    space           = Char -> Doc
    char Char
    ' '
    -- | The document @dot@ contains a single dot, \".\".
    dot :: Doc
    dot :: Doc
    dot             = Char -> Doc
    char Char
    '.'
    -- | The document @backslash@ contains a back slash, \"\\\".
    backslash :: Doc
    backslash :: Doc
    backslash       = Char -> Doc
    char Char
    '\\'
    -- | The document @equals@ contains an equal sign, \"=\".
    equals :: Doc
    equals :: Doc
    equals          = Char -> Doc
    char Char
    '='

    -----------------------------------------------------------
    -- Combinators for prelude types
    -----------------------------------------------------------

    -- string is like "text" but replaces '\n' by "line"

    -- | The document @(string s)@ concatenates all characters in @s@
    -- using @line@ for newline characters and @char@ for all other
    -- characters. It is used instead of 'text' whenever the text contains
    -- newline characters.
    string :: String -> Doc
    string :: String -> Doc
    string String
    ""       = Doc
    empty
    string (Char
    '\n':String
    s) = Doc
    line Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> String -> Doc
    string String
    s
    string String
    s        = case ((Char -> Bool) -> String -> (String, String)
    forall a. (a -> Bool) -> [a] -> ([a], [a])
    span (Char -> Char -> Bool
    forall a. Eq a => a -> a -> Bool
    /=Char
    '\n') String
    s) of
                        (String
    xs,String
    ys) -> String -> Doc
    text String
    xs Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> String -> Doc
    string String
    ys

    -- | The document @(bool b)@ shows the literal bool @b@ using 'text'.
    bool :: Bool -> Doc
    bool :: Bool -> Doc
    bool Bool
    b          = String -> Doc
    text (Bool -> String
    forall a. Show a => a -> String
    show Bool
    b)

    -- | The document @(int i)@ shows the literal integer @i@ using 'text'.
    int :: Int -> Doc
    int :: Int -> Doc
    int Int
    i           = String -> Doc
    text (Int -> String
    forall a. Show a => a -> String
    show Int
    i)

    -- | The document @(integer i)@ shows the literal integer @i@ using 'text'.
    integer :: Integer -> Doc
    integer :: Integer -> Doc
    integer Integer
    i       = String -> Doc
    text (Integer -> String
    forall a. Show a => a -> String
    show Integer
    i)

    -- | The document @(float f)@ shows the literal float @f@ using 'text'.
    float :: Float -> Doc
    float :: Float -> Doc
    float Float
    f         = String -> Doc
    text (Float -> String
    forall a. Show a => a -> String
    show Float
    f)

    -- | The document @(double d)@ shows the literal double @d@ using 'text'.
    double :: Double -> Doc
    double :: Double -> Doc
    double Double
    d        = String -> Doc
    text (Double -> String
    forall a. Show a => a -> String
    show Double
    d)

    -- | The document @(rational r)@ shows the literal rational @r@ using 'text'.
    rational :: Rational -> Doc
    rational :: Rational -> Doc
    rational Rational
    r      = String -> Doc
    text (Rational -> String
    forall a. Show a => a -> String
    show Rational
    r)

    -----------------------------------------------------------
    -- overloading "pretty"
    -----------------------------------------------------------

    -- | The member @prettyList@ is only used to define the @instance Pretty
    -- a => Pretty [a]@. In normal circumstances only the @pretty@ function
    -- is used.
    class Pretty a where
      pretty        :: a -> Doc
      prettyList    :: [a] -> Doc
      prettyList    = [Doc] -> Doc
    list ([Doc] -> Doc) -> ([a] -> [Doc]) -> [a] -> Doc
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . (a -> Doc) -> [a] -> [Doc]
    forall a b. (a -> b) -> [a] -> [b]
    map a -> Doc
    forall a. Pretty a => a -> Doc
    pretty

    instance Pretty a => Pretty [a] where
      pretty :: [a] -> Doc
    pretty        = [a] -> Doc
    forall a. Pretty a => [a] -> Doc
    prettyList

    instance Pretty Doc where
      pretty :: Doc -> Doc
    pretty        = Doc -> Doc
    forall a. a -> a
    id

    instance Pretty () where
      pretty :: () -> Doc
    pretty ()     = String -> Doc
    text String
    "()"

    instance Pretty Bool where
      pretty :: Bool -> Doc
    pretty Bool
    b      = Bool -> Doc
    bool Bool
    b

    instance Pretty Char where
      pretty :: Char -> Doc
    pretty Char
    c      = Char -> Doc
    char Char
    c
      prettyList :: String -> Doc
    prettyList String
    s  = String -> Doc
    string String
    s

    instance Pretty Int where
      pretty :: Int -> Doc
    pretty Int
    i      = Int -> Doc
    int Int
    i

    instance Pretty Integer where
      pretty :: Integer -> Doc
    pretty Integer
    i      = Integer -> Doc
    integer Integer
    i

    instance Pretty Float where
      pretty :: Float -> Doc
    pretty Float
    f      = Float -> Doc
    float Float
    f

    instance Pretty Double where
      pretty :: Double -> Doc
    pretty Double
    d      = Double -> Doc
    double Double
    d

    --instance Pretty Rational where
    --  pretty r      = rational r

    instance (Pretty a,Pretty b) => Pretty (a,b) where
      pretty :: (a, b) -> Doc
    pretty (a
    x,b
    y)  = [Doc] -> Doc
    tupled [a -> Doc
    forall a. Pretty a => a -> Doc
    pretty a
    x, b -> Doc
    forall a. Pretty a => a -> Doc
    pretty b
    y]

    instance (Pretty a,Pretty b,Pretty c) => Pretty (a,b,c) where
      pretty :: (a, b, c) -> Doc
    pretty (a
    x,b
    y,c
    z)= [Doc] -> Doc
    tupled [a -> Doc
    forall a. Pretty a => a -> Doc
    pretty a
    x, b -> Doc
    forall a. Pretty a => a -> Doc
    pretty b
    y, c -> Doc
    forall a. Pretty a => a -> Doc
    pretty c
    z]

    instance Pretty a => Pretty (Maybe a) where
      pretty :: Maybe a -> Doc
    pretty Maybe a
    Nothing        = Doc
    empty
      pretty (Just a
    x)       = a -> Doc
    forall a. Pretty a => a -> Doc
    pretty a
    x

    -----------------------------------------------------------
    -- semi primitive: fill and fillBreak
    -----------------------------------------------------------

    -- | The document @(fillBreak i x)@ first renders document @x@. It
    -- than appends @space@s until the width is equal to @i@. If the
    -- width of @x@ is already larger than @i@, the nesting level is
    -- increased by @i@ and a @line@ is appended. When we redefine @ptype@
    -- in the previous example to use @fillBreak@, we get a useful
    -- variation of the previous output:
    --
    -- > ptype (name,tp)
    -- >        = fillBreak 6 (text name) <+> text "::" <+> text tp
    --
    -- The output will now be:
    --
    -- @
    -- let empty  :: Doc
    --     nest   :: Int -> Doc -> Doc
    --     linebreak
    --            :: Doc
    -- @
    fillBreak :: Int -> Doc -> Doc
    fillBreak :: Int -> Doc -> Doc
    fillBreak Int
    f Doc
    x   = Doc -> (Int -> Doc) -> Doc
    width Doc
    x (\Int
    w ->
                      if (Int
    w Int -> Int -> Bool
    forall a. Ord a => a -> a -> Bool
    > Int
    f) then Int -> Doc -> Doc
    nest Int
    f Doc
    linebreak
                                 else String -> Doc
    text (Int -> String
    spaces (Int
    f Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    w)))

    -- | The document @(fill i x)@ renders document @x@. It than appends
    -- @space@s until the width is equal to @i@. If the width of @x@ is
    -- already larger, nothing is appended. This combinator is quite
    -- useful in practice to output a list of bindings. The following
    -- example demonstrates this.
    --
    -- > types  = [("empty","Doc")
    -- >          ,("nest","Int -> Doc -> Doc")
    -- >          ,("linebreak","Doc")]
    -- >
    -- > ptype (name,tp)
    -- >        = fill 6 (text name) <+> text "::" <+> text tp
    -- >
    -- > test   = text "let" <+> align (vcat (map ptype types))
    --
    -- Which is layed out as:
    --
    -- @
    -- let empty  :: Doc
    --     nest   :: Int -> Doc -> Doc
    --     linebreak :: Doc
    -- @
    fill :: Int -> Doc -> Doc
    fill :: Int -> Doc -> Doc
    fill Int
    f Doc
    d        = Doc -> (Int -> Doc) -> Doc
    width Doc
    d (\Int
    w ->
                      if (Int
    w Int -> Int -> Bool
    forall a. Ord a => a -> a -> Bool
    >= Int
    f) then Doc
    empty
                                  else String -> Doc
    text (Int -> String
    spaces (Int
    f Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    w)))

    width :: Doc -> (Int -> Doc) -> Doc
    width :: Doc -> (Int -> Doc) -> Doc
    width Doc
    d Int -> Doc
    f       = (Int -> Doc) -> Doc
    column (\Int
    k1 -> Doc
    d Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> (Int -> Doc) -> Doc
    column (\Int
    k2 -> Int -> Doc
    f (Int
    k2 Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    k1)))

    -----------------------------------------------------------
    -- semi primitive: Alignment and indentation
    -----------------------------------------------------------

    -- | The document @(indent i x)@ indents document @x@ with @i@ spaces.
    --
    -- > test  = indent 4 (fillSep (map text
    -- >         (words "the indent combinator indents these words !")))
    --
    -- Which lays out with a page width of 20 as:
    --
    -- @
    --     the indent
    --     combinator
    --     indents these
    --     words !
    -- @
    indent :: Int -> Doc -> Doc
    indent :: Int -> Doc -> Doc
    indent Int
    i Doc
    d      = Int -> Doc -> Doc
    hang Int
    i (String -> Doc
    text (Int -> String
    spaces Int
    i) Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    <> Doc
    d)

    -- | The hang combinator implements hanging indentation. The document
    -- @(hang i x)@ renders document @x@ with a nesting level set to the
    -- current column plus @i@. The following example uses hanging
    -- indentation for some text:
    --
    -- > test  = hang 4 (fillSep (map text
    -- >         (words "the hang combinator indents these words !")))
    --
    -- Which lays out on a page with a width of 20 characters as:
    --
    -- @
    -- the hang combinator
    --     indents these
    --     words !
    -- @
    --
    -- The @hang@ combinator is implemented as:
    --
    -- > hang i x  = align (nest i x)
    hang :: Int -> Doc -> Doc
    hang :: Int -> Doc -> Doc
    hang Int
    i Doc
    d        = Doc -> Doc
    align (Int -> Doc -> Doc
    nest Int
    i Doc
    d)

    -- | The document @(align x)@ renders document @x@ with the nesting
    -- level set to the current column. It is used for example to
    -- implement 'hang'.
    --
    -- As an example, we will put a document right above another one,
    -- regardless of the current nesting level:
    --
    -- > x $$ y  = align (x <$> y)
    --
    -- > test    = text "hi" <+> (text "nice" $$ text "world")
    --
    -- which will be layed out as:
    --
    -- @
    -- hi nice
    --    world
    -- @
    align :: Doc -> Doc
    align :: Doc -> Doc
    align Doc
    d         = (Int -> Doc) -> Doc
    column (\Int
    k ->
                      (Int -> Doc) -> Doc
    nesting (\Int
    i -> Int -> Doc -> Doc
    nest (Int
    k Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    i) Doc
    d))   --nesting might be negative :-)

    -----------------------------------------------------------
    -- Primitives
    -----------------------------------------------------------

    -- | The abstract data type @Doc@ represents pretty documents.
    --
    -- More specifically, a value of type @Doc@ represents a non-empty set of
    -- possible renderings of a document.  The rendering functions select one of
    -- these possibilities.
    --
    -- @Doc@ is an instance of the 'Show' class. @(show doc)@ pretty
    -- prints document @doc@ with a page width of 80 characters and a
    -- ribbon width of 32 characters.
    --
    -- > show (text "hello" <$> text "world")
    --
    -- Which would return the string \"hello\\nworld\", i.e.
    --
    -- @
    -- hello
    -- world
    -- @
    data Doc        = Fail
                    | Empty
                    | Char Char             -- invariant: char is not '\n'
                    | Text !Int String      -- invariant: text doesn't contain '\n'
                    | Line
                    | FlatAlt Doc Doc       -- Render the first doc, but when
                                            -- flattened, render the second.
                    | Cat Doc Doc
                    | Nest !Int Doc
                    | Union Doc Doc         -- invariant: first lines of first doc longer than the first lines of the second doc
                    | Column  (Int -> Doc)
                    | Columns (Maybe Int -> Doc)
                    | Nesting (Int -> Doc)
                    | Color ConsoleLayer ColorIntensity -- Introduces coloring /around/ the embedded document
                            Color Doc
                    | Intensify ConsoleIntensity Doc
                    | Italicize Bool Doc
                    | Underline Underlining Doc
                    | RestoreFormat (Maybe (ColorIntensity, Color))  -- Only used during the rendered phase, to signal a SGR should be issued to restore the terminal formatting.
                                    (Maybe (ColorIntensity, Color))  -- These are the colors to revert the current forecolor/backcolor to (i.e. those from before the start of the Color block).
                                    (Maybe ConsoleIntensity)         -- Intensity to revert to.
                                    (Maybe Bool)                     -- Italicization to revert to.
                                    (Maybe Underlining)              -- Underlining to revert to.

    -- | The data type @SimpleDoc@ represents rendered documents and is
    -- used by the display functions.
    --
    -- Whereas values of the data type 'Doc' represent non-empty sets of possible
    -- renderings of a document, values of the data type @SimpleDoc@ represent
    -- single renderings of a document.
    --
    -- The @Int@ in @SText@ contains the length of the string. The @Int@
    -- in @SLine@ contains the indentation for that line. The library
    -- provides two default display functions 'displayS' and
    -- 'displayIO'. You can provide your own display function by writing a
    -- function from a @SimpleDoc@ to your own output format.
    data SimpleDoc  = SFail
                    | SEmpty
                    | SChar Char SimpleDoc
                    | SText !Int String SimpleDoc
                    | SLine !Int SimpleDoc
                    | SSGR [SGR] SimpleDoc

    -- MCB: Not in the wl-pprint package that we forked from. I added this when the "pretty" package
    -- from base gained a Monoid instance (<http://hackage.haskell.org/trac/ghc/ticket/4378>):
    instance Monoid Doc where
        mempty :: Doc
    mempty = Doc
    empty
        mappend :: Doc -> Doc -> Doc
    mappend = Doc -> Doc -> Doc
    forall a. Semigroup a => a -> a -> a
    (Semi.<>)
        mconcat :: [Doc] -> Doc
    mconcat = [Doc] -> Doc
    hcat

    instance Semi.Semigroup Doc where
        <> :: Doc -> Doc -> Doc
    (<>) = Doc -> Doc -> Doc
    beside

    -- MCB: also added when "pretty" got the corresponding instances:
    instance IsString Doc where
        fromString :: String -> Doc
    fromString = String -> Doc
    text

    -- | The empty document is, indeed, empty. Although @empty@ has no
    -- content, it does have a \'height\' of 1 and behaves exactly like
    -- @(text \"\")@ (and is therefore not a unit of @\<$\>@).
    empty :: Doc
    empty :: Doc
    empty           = Doc
    Empty

    -- | The document @(char c)@ contains the literal character @c@. The
    -- character shouldn't be a newline (@'\n'@), the function 'line'
    -- should be used for line breaks.
    char :: Char -> Doc
    char :: Char -> Doc
    char Char
    '\n'       = Doc
    line
    char Char
    c          = Char -> Doc
    Char Char
    c

    -- | The document @(text s)@ contains the literal string @s@. The
    -- string shouldn't contain any newline (@'\n'@) characters. If the
    -- string contains newline characters, the function 'string' should be
    -- used.
    text :: String -> Doc
    text :: String -> Doc
    text String
    ""         = Doc
    Empty
    text String
    s          = Int -> String -> Doc
    Text (String -> Int
    forall a. [a] -> Int
    forall (t :: * -> *) a. Foldable t => t a -> Int
    length String
    s) String
    s

    -- | The @line@ document advances to the next line and indents to the
    -- current nesting level. Document @line@ behaves like @(text \" \")@
    -- if the line break is undone by 'group'.
    line :: Doc
    line :: Doc
    line            = Doc -> Doc -> Doc
    FlatAlt Doc
    Line Doc
    space

    -- | The @linebreak@ document advances to the next line and indents to
    -- the current nesting level. Document @linebreak@ behaves like
    -- 'empty' if the line break is undone by 'group'.
    linebreak :: Doc
    linebreak :: Doc
    linebreak       = Doc -> Doc -> Doc
    FlatAlt Doc
    Line Doc
    empty

    -- | A linebreak that will never be flattened; it is guaranteed to render
    -- as a newline.
    hardline :: Doc
    hardline :: Doc
    hardline = Doc
    Line

    beside :: Doc -> Doc -> Doc
    beside :: Doc -> Doc -> Doc
    beside Doc
    x Doc
    y      = Doc -> Doc -> Doc
    Cat Doc
    x Doc
    y

    -- | The document @(nest i x)@ renders document @x@ with the current
    -- indentation level increased by i (See also 'hang', 'align' and
    -- 'indent').
    --
    -- > nest 2 (text "hello" <$> text "world") <$> text "!"
    --
    -- outputs as:
    --
    -- @
    -- hello
    --   world
    -- !
    -- @
    nest :: Int -> Doc -> Doc
    nest :: Int -> Doc -> Doc
    nest Int
    i Doc
    x        = Int -> Doc -> Doc
    Nest Int
    i Doc
    x

    column, nesting :: (Int -> Doc) -> Doc
    column :: (Int -> Doc) -> Doc
    column Int -> Doc
    f        = (Int -> Doc) -> Doc
    Column Int -> Doc
    f
    nesting :: (Int -> Doc) -> Doc
    nesting Int -> Doc
    f       = (Int -> Doc) -> Doc
    Nesting Int -> Doc
    f

    columns :: (Maybe Int -> Doc) -> Doc
    columns :: (Maybe Int -> Doc) -> Doc
    columns Maybe Int -> Doc
    f       = (Maybe Int -> Doc) -> Doc
    Columns Maybe Int -> Doc
    f

    -- | The @group@ combinator is used to specify alternative
    -- layouts. The document @(group x)@ undoes all line breaks in
    -- document @x@. The resulting line is added to the current line if
    -- that fits the page. Otherwise, the document @x@ is rendered without
    -- any changes.
    group :: Doc -> Doc
    group :: Doc -> Doc
    group Doc
    x         = Doc -> Doc -> Doc
    Union (Doc -> Doc
    flatten Doc
    x) Doc
    x

    -- | A document that is normally rendered as the first argument, but
    -- when flattened, is rendered as the second document.
    flatAlt :: Doc -> Doc -> Doc
    flatAlt :: Doc -> Doc -> Doc
    flatAlt = Doc -> Doc -> Doc
    FlatAlt

    flatten :: Doc -> Doc
    flatten :: Doc -> Doc
    flatten (FlatAlt Doc
    x Doc
    y)    = Doc
    y
    flatten (Cat Doc
    x Doc
    y)        = Doc -> Doc -> Doc
    Cat (Doc -> Doc
    flatten Doc
    x) (Doc -> Doc
    flatten Doc
    y)
    flatten (Nest Int
    i Doc
    x)       = Int -> Doc -> Doc
    Nest Int
    i (Doc -> Doc
    flatten Doc
    x)
    flatten  Doc
    Line            = Doc
    Fail
    flatten (Union Doc
    x Doc
    y)      = Doc -> Doc
    flatten Doc
    x
    flatten (Column Int -> Doc
    f)       = (Int -> Doc) -> Doc
    Column (Doc -> Doc
    flatten (Doc -> Doc) -> (Int -> Doc) -> Int -> Doc
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Int -> Doc
    f)
    flatten (Columns Maybe Int -> Doc
    f)      = (Maybe Int -> Doc) -> Doc
    Columns (Doc -> Doc
    flatten (Doc -> Doc) -> (Maybe Int -> Doc) -> Maybe Int -> Doc
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Maybe Int -> Doc
    f)
    flatten (Nesting Int -> Doc
    f)      = (Int -> Doc) -> Doc
    Nesting (Doc -> Doc
    flatten (Doc -> Doc) -> (Int -> Doc) -> Int -> Doc
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Int -> Doc
    f)
    flatten (Color ConsoleLayer
    l ColorIntensity
    i Color
    c Doc
    x)  = ConsoleLayer -> ColorIntensity -> Color -> Doc -> Doc
    Color ConsoleLayer
    l ColorIntensity
    i Color
    c (Doc -> Doc
    flatten Doc
    x)
    flatten (Intensify ConsoleIntensity
    i Doc
    x)  = ConsoleIntensity -> Doc -> Doc
    Intensify ConsoleIntensity
    i (Doc -> Doc
    flatten Doc
    x)
    flatten (Italicize Bool
    b Doc
    x)  = Bool -> Doc -> Doc
    Italicize Bool
    b (Doc -> Doc
    flatten Doc
    x)
    flatten (Underline Underlining
    u Doc
    x)  = Underlining -> Doc -> Doc
    Underline Underlining
    u (Doc -> Doc
    flatten Doc
    x)
    flatten Doc
    other            = Doc
    other                     --Empty,Char,Text,RestoreFormat

    -----------------------------------------------------------
    -- Colors
    -----------------------------------------------------------

    -- | Displays a document with the black forecolor
    black :: Doc -> Doc
    -- | Displays a document with the red forecolor
    red :: Doc -> Doc
    -- | Displays a document with the green forecolor
    green :: Doc -> Doc
    -- | Displays a document with the yellow forecolor
    yellow :: Doc -> Doc
    -- | Displays a document with the blue forecolor
    blue :: Doc -> Doc
    -- | Displays a document with the magenta forecolor
    magenta :: Doc -> Doc
    -- | Displays a document with the cyan forecolor
    cyan :: Doc -> Doc
    -- | Displays a document with the white forecolor
    white :: Doc -> Doc
    -- | Displays a document with the dull black forecolor
    dullblack :: Doc -> Doc
    -- | Displays a document with the dull red forecolor
    dullred :: Doc -> Doc
    -- | Displays a document with the dull green forecolor
    dullgreen :: Doc -> Doc
    -- | Displays a document with the dull yellow forecolor
    dullyellow :: Doc -> Doc
    -- | Displays a document with the dull blue forecolor
    dullblue :: Doc -> Doc
    -- | Displays a document with the dull magenta forecolor
    dullmagenta :: Doc -> Doc
    -- | Displays a document with the dull cyan forecolor
    dullcyan :: Doc -> Doc
    -- | Displays a document with the dull white forecolor
    dullwhite :: Doc -> Doc
    (Doc -> Doc
    black, Doc -> Doc
    dullblack)     = Color -> (Doc -> Doc, Doc -> Doc)
    colorFunctions Color
    Black
    (Doc -> Doc
    red, Doc -> Doc
    dullred)         = Color -> (Doc -> Doc, Doc -> Doc)
    colorFunctions Color
    Red
    (Doc -> Doc
    green, Doc -> Doc
    dullgreen)     = Color -> (Doc -> Doc, Doc -> Doc)
    colorFunctions Color
    Green
    (Doc -> Doc
    yellow, Doc -> Doc
    dullyellow)   = Color -> (Doc -> Doc, Doc -> Doc)
    colorFunctions Color
    Yellow
    (Doc -> Doc
    blue, Doc -> Doc
    dullblue)       = Color -> (Doc -> Doc, Doc -> Doc)
    colorFunctions Color
    Blue
    (Doc -> Doc
    magenta, Doc -> Doc
    dullmagenta) = Color -> (Doc -> Doc, Doc -> Doc)
    colorFunctions Color
    Magenta
    (Doc -> Doc
    cyan, Doc -> Doc
    dullcyan)       = Color -> (Doc -> Doc, Doc -> Doc)
    colorFunctions Color
    Cyan
    (Doc -> Doc
    white, Doc -> Doc
    dullwhite)     = Color -> (Doc -> Doc, Doc -> Doc)
    colorFunctions Color
    White

    -- | Displays a document with a forecolor given in the first parameter
    color :: Color -> Doc -> Doc
    -- | Displays a document with a dull forecolor given in the first parameter
    dullcolor :: Color -> Doc -> Doc
    color :: Color -> Doc -> Doc
    color     = ConsoleLayer -> ColorIntensity -> Color -> Doc -> Doc
    Color ConsoleLayer
    Foreground ColorIntensity
    Vivid
    dullcolor :: Color -> Doc -> Doc
    dullcolor = ConsoleLayer -> ColorIntensity -> Color -> Doc -> Doc
    Color ConsoleLayer
    Foreground ColorIntensity
    Dull

    colorFunctions :: Color -> (Doc -> Doc, Doc -> Doc)
    colorFunctions :: Color -> (Doc -> Doc, Doc -> Doc)
    colorFunctions Color
    what = (Color -> Doc -> Doc
    color Color
    what, Color -> Doc -> Doc
    dullcolor Color
    what)

    -- | Displays a document with the black backcolor
    onblack :: Doc -> Doc
    -- | Displays a document with the red backcolor
    onred :: Doc -> Doc
    -- | Displays a document with the green backcolor
    ongreen :: Doc -> Doc
    -- | Displays a document with the yellow backcolor
    onyellow :: Doc -> Doc
    -- | Displays a document with the blue backcolor
    onblue :: Doc -> Doc
    -- | Displays a document with the magenta backcolor
    onmagenta :: Doc -> Doc
    -- | Displays a document with the cyan backcolor
    oncyan :: Doc -> Doc
    -- | Displays a document with the white backcolor
    onwhite :: Doc -> Doc
    -- | Displays a document with the dull black backcolor
    ondullblack :: Doc -> Doc
    -- | Displays a document with the dull red backcolor
    ondullred :: Doc -> Doc
    -- | Displays a document with the dull green backcolor
    ondullgreen :: Doc -> Doc
    -- | Displays a document with the dull yellow backcolor
    ondullyellow :: Doc -> Doc
    -- | Displays a document with the dull blue backcolor
    ondullblue :: Doc -> Doc
    -- | Displays a document with the dull magenta backcolor
    ondullmagenta :: Doc -> Doc
    -- | Displays a document with the dull cyan backcolor
    ondullcyan :: Doc -> Doc
    -- | Displays a document with the dull white backcolor
    ondullwhite :: Doc -> Doc
    (Doc -> Doc
    onblack, Doc -> Doc
    ondullblack)     = Color -> (Doc -> Doc, Doc -> Doc)
    oncolorFunctions Color
    Black
    (Doc -> Doc
    onred, Doc -> Doc
    ondullred)         = Color -> (Doc -> Doc, Doc -> Doc)
    oncolorFunctions Color
    Red
    (Doc -> Doc
    ongreen, Doc -> Doc
    ondullgreen)     = Color -> (Doc -> Doc, Doc -> Doc)
    oncolorFunctions Color
    Green
    (Doc -> Doc
    onyellow, Doc -> Doc
    ondullyellow)   = Color -> (Doc -> Doc, Doc -> Doc)
    oncolorFunctions Color
    Yellow
    (Doc -> Doc
    onblue, Doc -> Doc
    ondullblue)       = Color -> (Doc -> Doc, Doc -> Doc)
    oncolorFunctions Color
    Blue
    (Doc -> Doc
    onmagenta, Doc -> Doc
    ondullmagenta) = Color -> (Doc -> Doc, Doc -> Doc)
    oncolorFunctions Color
    Magenta
    (Doc -> Doc
    oncyan, Doc -> Doc
    ondullcyan)       = Color -> (Doc -> Doc, Doc -> Doc)
    oncolorFunctions Color
    Cyan
    (Doc -> Doc
    onwhite, Doc -> Doc
    ondullwhite)     = Color -> (Doc -> Doc, Doc -> Doc)
    oncolorFunctions Color
    White

    -- | Displays a document with a backcolor given in the first parameter
    oncolor :: Color -> Doc -> Doc
    -- | Displays a document with a dull backcolor given in the first parameter
    ondullcolor :: Color -> Doc -> Doc
    oncolor :: Color -> Doc -> Doc
    oncolor     = ConsoleLayer -> ColorIntensity -> Color -> Doc -> Doc
    Color ConsoleLayer
    Background ColorIntensity
    Vivid
    ondullcolor :: Color -> Doc -> Doc
    ondullcolor = ConsoleLayer -> ColorIntensity -> Color -> Doc -> Doc
    Color ConsoleLayer
    Background ColorIntensity
    Dull

    oncolorFunctions :: Color -> (Doc -> Doc, Doc -> Doc)
    oncolorFunctions :: Color -> (Doc -> Doc, Doc -> Doc)
    oncolorFunctions Color
    what = (Color -> Doc -> Doc
    oncolor Color
    what, Color -> Doc -> Doc
    ondullcolor Color
    what)

    -----------------------------------------------------------
    -- Console Intensity
    -----------------------------------------------------------

    -- | Displays a document in a heavier font weight
    bold :: Doc -> Doc
    bold :: Doc -> Doc
    bold = ConsoleIntensity -> Doc -> Doc
    Intensify ConsoleIntensity
    BoldIntensity

    -- | Displays a document in the normal font weight
    debold :: Doc -> Doc
    debold :: Doc -> Doc
    debold = ConsoleIntensity -> Doc -> Doc
    Intensify ConsoleIntensity
    NormalIntensity

    -- NB: I don't support FaintIntensity here because it is not widely supported by terminals.

    -----------------------------------------------------------
    -- Italicization
    -----------------------------------------------------------

    {-

    I'm in two minds about providing these functions, since italicization is so rarely implemented.
    It is especially bad because "italicization" may cause the meaning of colors to flip, which will
    look a bit weird, to say the least...

    -- | Displays a document in italics. This is not widely supported, and it's use is not recommended
    italicize :: Doc -> Doc
    italicize = Italicize True

    -- | Displays a document with no italics
    deitalicize :: Doc -> Doc
    deitalicize = Italicize False

    -}

    -----------------------------------------------------------
    -- Underlining
    -----------------------------------------------------------

    -- | Displays a document with underlining
    underline :: Doc -> Doc
    underline :: Doc -> Doc
    underline = Underlining -> Doc -> Doc
    Underline Underlining
    SingleUnderline

    -- | Displays a document with no underlining
    deunderline :: Doc -> Doc
    deunderline :: Doc -> Doc
    deunderline = Underlining -> Doc -> Doc
    Underline Underlining
    NoUnderline

    -- NB: I don't support DoubleUnderline here because it is not widely supported by terminals.

    -----------------------------------------------------------
    -- Removing formatting
    -----------------------------------------------------------

    -- | Removes all colorisation, emboldening and underlining from a document
    plain :: Doc -> Doc
    plain :: Doc -> Doc
    plain Doc
    Fail            = Doc
    Fail
    plain e :: Doc
    e@Doc
    Empty         = Doc
    e
    plain c :: Doc
    c@(Char Char
    _)      = Doc
    c
    plain t :: Doc
    t@(Text Int
    _ String
    _)    = Doc
    t
    plain l :: Doc
    l@Doc
    Line          = Doc
    l
    plain (FlatAlt Doc
    x Doc
    y)   = Doc -> Doc -> Doc
    FlatAlt (Doc -> Doc
    plain Doc
    x) (Doc -> Doc
    plain Doc
    y)
    plain (Cat Doc
    x Doc
    y)       = Doc -> Doc -> Doc
    Cat (Doc -> Doc
    plain Doc
    x) (Doc -> Doc
    plain Doc
    y)
    plain (Nest Int
    i Doc
    x)      = Int -> Doc -> Doc
    Nest Int
    i (Doc -> Doc
    plain Doc
    x)
    plain (Union Doc
    x Doc
    y)     = Doc -> Doc -> Doc
    Union (Doc -> Doc
    plain Doc
    x) (Doc -> Doc
    plain Doc
    y)
    plain (Column Int -> Doc
    f)      = (Int -> Doc) -> Doc
    Column (Doc -> Doc
    plain (Doc -> Doc) -> (Int -> Doc) -> Int -> Doc
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Int -> Doc
    f)
    plain (Columns Maybe Int -> Doc
    f)     = (Maybe Int -> Doc) -> Doc
    Columns (Doc -> Doc
    plain (Doc -> Doc) -> (Maybe Int -> Doc) -> Maybe Int -> Doc
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Maybe Int -> Doc
    f)
    plain (Nesting Int -> Doc
    f)     = (Int -> Doc) -> Doc
    Nesting (Doc -> Doc
    plain (Doc -> Doc) -> (Int -> Doc) -> Int -> Doc
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Int -> Doc
    f)
    plain (Color ConsoleLayer
    _ ColorIntensity
    _ Color
    _ Doc
    x) = Doc -> Doc
    plain Doc
    x
    plain (Intensify ConsoleIntensity
    _ Doc
    x) = Doc -> Doc
    plain Doc
    x
    plain (Italicize Bool
    _ Doc
    x) = Doc -> Doc
    plain Doc
    x
    plain (Underline Underlining
    _ Doc
    x) = Doc -> Doc
    plain Doc
    x
    plain (RestoreFormat Maybe (ColorIntensity, Color)
    _ Maybe (ColorIntensity, Color)
    _ Maybe ConsoleIntensity
    _ Maybe Bool
    _ Maybe Underlining
    _) = Doc
    Empty

    -----------------------------------------------------------
    -- Renderers
    -----------------------------------------------------------

    -----------------------------------------------------------
    -- renderPretty: the default pretty printing algorithm
    -----------------------------------------------------------

    -- list of indentation/document pairs; saves an indirection over [(Int,Doc)]
    data Docs   = Nil
                | Cons !Int Doc Docs

    -- | This is the default pretty printer which is used by 'show',
    -- 'putDoc' and 'hPutDoc'. @(renderPretty ribbonfrac width x)@ renders
    -- document @x@ with a page width of @width@ and a ribbon width of
    -- @(ribbonfrac * width)@ characters. The ribbon width is the maximal
    -- amount of non-indentation characters on a line. The parameter
    -- @ribbonfrac@ should be between @0.0@ and @1.0@. If it is lower or
    -- higher, the ribbon width will be 0 or @width@ respectively.
    renderPretty :: Float -> Int -> Doc -> SimpleDoc
    renderPretty :: Float -> Int -> Doc -> SimpleDoc
    renderPretty = (Int -> Int -> Int -> SimpleDoc -> Bool)
    -> Float -> Int -> Doc -> SimpleDoc
    renderFits Int -> Int -> Int -> SimpleDoc -> Bool
    fits1

    -- | A slightly smarter rendering algorithm with more lookahead. It provides
    -- provide earlier breaking on deeply nested structures
    -- For example, consider this python-ish pseudocode:
    -- @fun(fun(fun(fun(fun([abcdefg, abcdefg])))))@
    -- If we put a softbreak (+ nesting 2) after each open parenthesis, and align
    -- the elements of the list to match the opening brackets, this will render with
    -- @renderPretty@ and a page width of 20 as:
    -- @
    -- fun(fun(fun(fun(fun([
    --                     | abcdef,
    --                     | abcdef,
    --                     ]
    --   )))))             |
    -- @
    -- Where the 20c. boundary has been marked with |.
    -- Because @renderPretty@ only uses one-line lookahead, it sees that the first
    -- line fits, and is stuck putting the second and third lines after the 20-c
    -- mark. In contrast, @renderSmart@ will continue to check that the potential
    -- document up to the end of the indentation level. Thus, it will format the
    -- document as:
    --
    -- @
    -- fun(                |
    --   fun(              |
    --     fun(            |
    --       fun(          |
    --         fun([       |
    --               abcdef,
    --               abcdef,
    --             ]       |
    --   )))))             |
    -- @
    -- Which fits within the 20c. boundary.
    renderSmart :: Float -> Int -> Doc -> SimpleDoc
    renderSmart :: Float -> Int -> Doc -> SimpleDoc
    renderSmart = (Int -> Int -> Int -> SimpleDoc -> Bool)
    -> Float -> Int -> Doc -> SimpleDoc
    renderFits Int -> Int -> Int -> SimpleDoc -> Bool
    fitsR

    renderFits :: (Int -> Int -> Int -> SimpleDoc -> Bool)
               -> Float -> Int -> Doc -> SimpleDoc
    renderFits :: (Int -> Int -> Int -> SimpleDoc -> Bool)
    -> Float -> Int -> Doc -> SimpleDoc
    renderFits Int -> Int -> Int -> SimpleDoc -> Bool
    fits Float
    rfrac Int
    w Doc
    x
        -- I used to do a @SSGR [Reset]@ here, but if you do that it will result
        -- in any rendered @Doc@ containing at least some ANSI control codes. This
        -- may be undesirable if you want to render to non-ANSI devices by simply
        -- not making use of the ANSI color combinators I provide.
        --
        -- What I "really" want to do here is do an initial Reset iff there is some
        -- ANSI color within the Doc, but that's a bit fiddly. I'll fix it if someone
        -- complains!
        = Int
    -> Int
    -> Maybe (ColorIntensity, Color)
    -> Maybe (ColorIntensity, Color)
    -> Maybe ConsoleIntensity
    -> Maybe Bool
    -> Maybe Underlining
    -> Docs
    -> SimpleDoc
    best Int
    0 Int
    0 Maybe (ColorIntensity, Color)
    forall a. Maybe a
    Nothing Maybe (ColorIntensity, Color)
    forall a. Maybe a
    Nothing Maybe ConsoleIntensity
    forall a. Maybe a
    Nothing Maybe Bool
    forall a. Maybe a
    Nothing Maybe Underlining
    forall a. Maybe a
    Nothing (Int -> Doc -> Docs -> Docs
    Cons Int
    0 Doc
    x Docs
    Nil)
        where
          -- r :: the ribbon width in characters
          r :: Int
    r  = Int -> Int -> Int
    forall a. Ord a => a -> a -> a
    max Int
    0 (Int -> Int -> Int
    forall a. Ord a => a -> a -> a
    min Int
    w (Float -> Int
    forall b. Integral b => Float -> b
    forall a b. (RealFrac a, Integral b) => a -> b
    round (Int -> Float
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    w Float -> Float -> Float
    forall a. Num a => a -> a -> a
    * Float
    rfrac)))

          -- best :: n = indentation of current line
          --         k = current column
          --        (ie. (k >= n) && (k - n == count of inserted characters)
          best :: Int
    -> Int
    -> Maybe (ColorIntensity, Color)
    -> Maybe (ColorIntensity, Color)
    -> Maybe ConsoleIntensity
    -> Maybe Bool
    -> Maybe Underlining
    -> Docs
    -> SimpleDoc
    best Int
    n Int
    k Maybe (ColorIntensity, Color)
    mb_fc Maybe (ColorIntensity, Color)
    mb_bc Maybe ConsoleIntensity
    mb_in Maybe Bool
    mb_it Maybe Underlining
    mb_un Docs
    Nil = SimpleDoc
    SEmpty
          best Int
    n Int
    k Maybe (ColorIntensity, Color)
    mb_fc Maybe (ColorIntensity, Color)
    mb_bc Maybe ConsoleIntensity
    mb_in Maybe Bool
    mb_it Maybe Underlining
    mb_un (Cons Int
    i Doc
    d Docs
    ds)
            = case Doc
    d of
                Doc
    Fail          -> SimpleDoc
    SFail
                Doc
    Empty         -> Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n Int
    k Docs
    ds
                Char Char
    c        -> let k' :: Int
    k' = Int
    kInt -> Int -> Int
    forall a. Num a => a -> a -> a
    +Int
    1 in Int -> SimpleDoc -> SimpleDoc
    forall a b. a -> b -> b
    seq Int
    k' (Char -> SimpleDoc -> SimpleDoc
    SChar Char
    c (Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n Int
    k' Docs
    ds))
                Text Int
    l String
    s      -> let k' :: Int
    k' = Int
    kInt -> Int -> Int
    forall a. Num a => a -> a -> a
    +Int
    l in Int -> SimpleDoc -> SimpleDoc
    forall a b. a -> b -> b
    seq Int
    k' (Int -> String -> SimpleDoc -> SimpleDoc
    SText Int
    l String
    s (Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n Int
    k' Docs
    ds))
                Doc
    Line          -> Int -> SimpleDoc -> SimpleDoc
    SLine Int
    i (Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    i Int
    i Docs
    ds)
                FlatAlt Doc
    x Doc
    _   -> Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n Int
    k (Int -> Doc -> Docs -> Docs
    Cons Int
    i Doc
    x Docs
    ds)
                Cat Doc
    x Doc
    y       -> Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n Int
    k (Int -> Doc -> Docs -> Docs
    Cons Int
    i Doc
    x (Int -> Doc -> Docs -> Docs
    Cons Int
    i Doc
    y Docs
    ds))
                Nest Int
    j Doc
    x      -> let i' :: Int
    i' = Int
    iInt -> Int -> Int
    forall a. Num a => a -> a -> a
    +Int
    j in Int -> SimpleDoc -> SimpleDoc
    forall a b. a -> b -> b
    seq Int
    i' (Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n Int
    k (Int -> Doc -> Docs -> Docs
    Cons Int
    i' Doc
    x Docs
    ds))
                Union Doc
    x Doc
    y     -> Int -> Int -> SimpleDoc -> SimpleDoc -> SimpleDoc
    nicest Int
    n Int
    k (Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n Int
    k (Int -> Doc -> Docs -> Docs
    Cons Int
    i Doc
    x Docs
    ds))
                                            (Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n Int
    k (Int -> Doc -> Docs -> Docs
    Cons Int
    i Doc
    y Docs
    ds))
                Column Int -> Doc
    f      -> Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n Int
    k (Int -> Doc -> Docs -> Docs
    Cons Int
    i (Int -> Doc
    f Int
    k) Docs
    ds)
                Columns Maybe Int -> Doc
    f     -> Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n Int
    k (Int -> Doc -> Docs -> Docs
    Cons Int
    i (Maybe Int -> Doc
    f (Int -> Maybe Int
    forall a. a -> Maybe a
    Just Int
    w)) Docs
    ds)
                Nesting Int -> Doc
    f     -> Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n Int
    k (Int -> Doc -> Docs -> Docs
    Cons Int
    i (Int -> Doc
    f Int
    i) Docs
    ds)
                Color ConsoleLayer
    l ColorIntensity
    t Color
    c Doc
    x -> [SGR] -> SimpleDoc -> SimpleDoc
    SSGR [ConsoleLayer -> ColorIntensity -> Color -> SGR
    SetColor ConsoleLayer
    l ColorIntensity
    t Color
    c] (Int
    -> Int
    -> Maybe (ColorIntensity, Color)
    -> Maybe (ColorIntensity, Color)
    -> Maybe ConsoleIntensity
    -> Maybe Bool
    -> Maybe Underlining
    -> Docs
    -> SimpleDoc
    best Int
    n Int
    k Maybe (ColorIntensity, Color)
    mb_fc' Maybe (ColorIntensity, Color)
    mb_bc' Maybe ConsoleIntensity
    mb_in Maybe Bool
    mb_it Maybe Underlining
    mb_un (Int -> Doc -> Docs -> Docs
    Cons Int
    i Doc
    x Docs
    ds_restore))
                  where
                    mb_fc' :: Maybe (ColorIntensity, Color)
    mb_fc' = case ConsoleLayer
    l of { ConsoleLayer
    Background -> Maybe (ColorIntensity, Color)
    mb_fc; ConsoleLayer
    Foreground -> (ColorIntensity, Color) -> Maybe (ColorIntensity, Color)
    forall a. a -> Maybe a
    Just (ColorIntensity
    t, Color
    c) }
                    mb_bc' :: Maybe (ColorIntensity, Color)
    mb_bc' = case ConsoleLayer
    l of { ConsoleLayer
    Background -> (ColorIntensity, Color) -> Maybe (ColorIntensity, Color)
    forall a. a -> Maybe a
    Just (ColorIntensity
    t, Color
    c); ConsoleLayer
    Foreground -> Maybe (ColorIntensity, Color)
    mb_bc }
                Intensify ConsoleIntensity
    t Doc
    x -> [SGR] -> SimpleDoc -> SimpleDoc
    SSGR [ConsoleIntensity -> SGR
    SetConsoleIntensity ConsoleIntensity
    t] (Int
    -> Int
    -> Maybe (ColorIntensity, Color)
    -> Maybe (ColorIntensity, Color)
    -> Maybe ConsoleIntensity
    -> Maybe Bool
    -> Maybe Underlining
    -> Docs
    -> SimpleDoc
    best Int
    n Int
    k Maybe (ColorIntensity, Color)
    mb_fc Maybe (ColorIntensity, Color)
    mb_bc (ConsoleIntensity -> Maybe ConsoleIntensity
    forall a. a -> Maybe a
    Just ConsoleIntensity
    t) Maybe Bool
    mb_it Maybe Underlining
    mb_un (Int -> Doc -> Docs -> Docs
    Cons Int
    i Doc
    x Docs
    ds_restore))
                Italicize Bool
    t Doc
    x -> [SGR] -> SimpleDoc -> SimpleDoc
    SSGR [Bool -> SGR
    SetItalicized Bool
    t] (Int
    -> Int
    -> Maybe (ColorIntensity, Color)
    -> Maybe (ColorIntensity, Color)
    -> Maybe ConsoleIntensity
    -> Maybe Bool
    -> Maybe Underlining
    -> Docs
    -> SimpleDoc
    best Int
    n Int
    k Maybe (ColorIntensity, Color)
    mb_fc Maybe (ColorIntensity, Color)
    mb_bc Maybe ConsoleIntensity
    mb_in (Bool -> Maybe Bool
    forall a. a -> Maybe a
    Just Bool
    t) Maybe Underlining
    mb_un (Int -> Doc -> Docs -> Docs
    Cons Int
    i Doc
    x Docs
    ds_restore))
                Underline Underlining
    u Doc
    x -> [SGR] -> SimpleDoc -> SimpleDoc
    SSGR [Underlining -> SGR
    SetUnderlining Underlining
    u] (Int
    -> Int
    -> Maybe (ColorIntensity, Color)
    -> Maybe (ColorIntensity, Color)
    -> Maybe ConsoleIntensity
    -> Maybe Bool
    -> Maybe Underlining
    -> Docs
    -> SimpleDoc
    best Int
    n Int
    k Maybe (ColorIntensity, Color)
    mb_fc Maybe (ColorIntensity, Color)
    mb_bc Maybe ConsoleIntensity
    mb_in Maybe Bool
    mb_it (Underlining -> Maybe Underlining
    forall a. a -> Maybe a
    Just Underlining
    u) (Int -> Doc -> Docs -> Docs
    Cons Int
    i Doc
    x Docs
    ds_restore))
                RestoreFormat Maybe (ColorIntensity, Color)
    mb_fc' Maybe (ColorIntensity, Color)
    mb_bc' Maybe ConsoleIntensity
    mb_in' Maybe Bool
    mb_it' Maybe Underlining
    mb_un' -> [SGR] -> SimpleDoc -> SimpleDoc
    SSGR [SGR]
    sgrs (Int
    -> Int
    -> Maybe (ColorIntensity, Color)
    -> Maybe (ColorIntensity, Color)
    -> Maybe ConsoleIntensity
    -> Maybe Bool
    -> Maybe Underlining
    -> Docs
    -> SimpleDoc
    best Int
    n Int
    k Maybe (ColorIntensity, Color)
    mb_fc' Maybe (ColorIntensity, Color)
    mb_bc' Maybe ConsoleIntensity
    mb_in' Maybe Bool
    mb_it' Maybe Underlining
    mb_un' Docs
    ds)
                  where
                    -- We need to be able to restore the entire SGR state, hence we carry around what we believe
                    -- that state should be in all the arguments to this function. Note that in some cases we could
                    -- avoid the Reset of the entire state, but not in general.
                    sgrs :: [SGR]
    sgrs = SGR
    Reset SGR -> [SGR] -> [SGR]
    forall a. a -> [a] -> [a]
    : [Maybe SGR] -> [SGR]
    forall a. [Maybe a] -> [a]
    catMaybes [
                        ((ColorIntensity, Color) -> SGR)
    -> Maybe (ColorIntensity, Color) -> Maybe SGR
    forall a b. (a -> b) -> Maybe a -> Maybe b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap ((ColorIntensity -> Color -> SGR) -> (ColorIntensity, Color) -> SGR
    forall a b c. (a -> b -> c) -> (a, b) -> c
    uncurry (ConsoleLayer -> ColorIntensity -> Color -> SGR
    SetColor ConsoleLayer
    Foreground)) Maybe (ColorIntensity, Color)
    mb_fc',
                        ((ColorIntensity, Color) -> SGR)
    -> Maybe (ColorIntensity, Color) -> Maybe SGR
    forall a b. (a -> b) -> Maybe a -> Maybe b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap ((ColorIntensity -> Color -> SGR) -> (ColorIntensity, Color) -> SGR
    forall a b c. (a -> b -> c) -> (a, b) -> c
    uncurry (ConsoleLayer -> ColorIntensity -> Color -> SGR
    SetColor ConsoleLayer
    Background)) Maybe (ColorIntensity, Color)
    mb_bc',
                        (ConsoleIntensity -> SGR) -> Maybe ConsoleIntensity -> Maybe SGR
    forall a b. (a -> b) -> Maybe a -> Maybe b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap ConsoleIntensity -> SGR
    SetConsoleIntensity Maybe ConsoleIntensity
    mb_in',
                        (Bool -> SGR) -> Maybe Bool -> Maybe SGR
    forall a b. (a -> b) -> Maybe a -> Maybe b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap Bool -> SGR
    SetItalicized Maybe Bool
    mb_it',
                        (Underlining -> SGR) -> Maybe Underlining -> Maybe SGR
    forall a b. (a -> b) -> Maybe a -> Maybe b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap Underlining -> SGR
    SetUnderlining Maybe Underlining
    mb_un'
                      ]
            where
              best_typical :: Int -> Int -> Docs -> SimpleDoc
    best_typical Int
    n' Int
    k' Docs
    ds' = Int
    -> Int
    -> Maybe (ColorIntensity, Color)
    -> Maybe (ColorIntensity, Color)
    -> Maybe ConsoleIntensity
    -> Maybe Bool
    -> Maybe Underlining
    -> Docs
    -> SimpleDoc
    best Int
    n' Int
    k' Maybe (ColorIntensity, Color)
    mb_fc Maybe (ColorIntensity, Color)
    mb_bc Maybe ConsoleIntensity
    mb_in Maybe Bool
    mb_it Maybe Underlining
    mb_un Docs
    ds'
              ds_restore :: Docs
    ds_restore = Int -> Doc -> Docs -> Docs
    Cons Int
    i (Maybe (ColorIntensity, Color)
    -> Maybe (ColorIntensity, Color)
    -> Maybe ConsoleIntensity
    -> Maybe Bool
    -> Maybe Underlining
    -> Doc
    RestoreFormat Maybe (ColorIntensity, Color)
    mb_fc Maybe (ColorIntensity, Color)
    mb_bc Maybe ConsoleIntensity
    mb_in Maybe Bool
    mb_it Maybe Underlining
    mb_un) Docs
    ds

          --nicest :: r = ribbon width, w = page width,
          --          n = indentation of current line, k = current column
          --          x and y, the (simple) documents to chose from.
          --          precondition: first lines of x are longer than the first lines of y.
          nicest :: Int -> Int -> SimpleDoc -> SimpleDoc -> SimpleDoc
    nicest Int
    n Int
    k SimpleDoc
    x SimpleDoc
    y    | Int -> Int -> Int -> SimpleDoc -> Bool
    fits Int
    w (Int -> Int -> Int
    forall a. Ord a => a -> a -> a
    min Int
    n Int
    k) Int
    width SimpleDoc
    x  = SimpleDoc
    x
                            | Bool
    otherwise     = SimpleDoc
    y
                            where
                              width :: Int
    width = Int -> Int -> Int
    forall a. Ord a => a -> a -> a
    min (Int
    w Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    k) (Int
    r Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    k Int -> Int -> Int
    forall a. Num a => a -> a -> a
    + Int
    n)

    -- @fits1@ does 1 line lookahead.
    fits1 :: Int -> Int -> Int -> SimpleDoc -> Bool
    fits1 :: Int -> Int -> Int -> SimpleDoc -> Bool
    fits1 Int
    _ Int
    _ Int
    w SimpleDoc
    x        | Int
    w Int -> Int -> Bool
    forall a. Ord a => a -> a -> Bool
    < Int
    0         = Bool
    False
    fits1 Int
    _ Int
    _ Int
    w SimpleDoc
    SFail                    = Bool
    False
    fits1 Int
    _ Int
    _ Int
    w SimpleDoc
    SEmpty                   = Bool
    True
    fits1 Int
    p Int
    m Int
    w (SChar Char
    c SimpleDoc
    x)              = Int -> Int -> Int -> SimpleDoc -> Bool
    fits1 Int
    p Int
    m (Int
    w Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    1) SimpleDoc
    x
    fits1 Int
    p Int
    m Int
    w (SText Int
    l String
    s SimpleDoc
    x)            = Int -> Int -> Int -> SimpleDoc -> Bool
    fits1 Int
    p Int
    m (Int
    w Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    l) SimpleDoc
    x
    fits1 Int
    _ Int
    _ Int
    w (SLine Int
    i SimpleDoc
    x)              = Bool
    True
    fits1 Int
    p Int
    m Int
    w (SSGR [SGR]
    _ SimpleDoc
    x)               = Int -> Int -> Int -> SimpleDoc -> Bool
    fits1 Int
    p Int
    m Int
    w SimpleDoc
    x

    -- @fitsR@ has a little more lookahead: assuming that nesting roughly
    -- corresponds to syntactic depth, @fitsR@ checks that not only the current line
    -- fits, but the entire syntactic structure being formatted at this level of
    -- indentation fits. If we were to remove the second case for @SLine@, we would
    -- check that not only the current structure fits, but also the rest of the
    -- document, which would be slightly more intelligent but would have exponential
    -- runtime (and is prohibitively expensive in practice).
    -- p = pagewidth
    -- m = minimum nesting level to fit in
    -- w = the width in which to fit the first line
    fitsR :: Int -> Int -> Int -> SimpleDoc -> Bool
    fitsR :: Int -> Int -> Int -> SimpleDoc -> Bool
    fitsR Int
    p Int
    m Int
    w SimpleDoc
    x        | Int
    w Int -> Int -> Bool
    forall a. Ord a => a -> a -> Bool
    < Int
    0         = Bool
    False
    fitsR Int
    p Int
    m Int
    w SimpleDoc
    SFail                    = Bool
    False
    fitsR Int
    p Int
    m Int
    w SimpleDoc
    SEmpty                   = Bool
    True
    fitsR Int
    p Int
    m Int
    w (SChar Char
    c SimpleDoc
    x)              = Int -> Int -> Int -> SimpleDoc -> Bool
    fitsR Int
    p Int
    m (Int
    w Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    1) SimpleDoc
    x
    fitsR Int
    p Int
    m Int
    w (SText Int
    l String
    s SimpleDoc
    x)            = Int -> Int -> Int -> SimpleDoc -> Bool
    fitsR Int
    p Int
    m (Int
    w Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    l) SimpleDoc
    x
    fitsR Int
    p Int
    m Int
    w (SLine Int
    i SimpleDoc
    x) | Int
    m Int -> Int -> Bool
    forall a. Ord a => a -> a -> Bool
    < Int
    i      = Int -> Int -> Int -> SimpleDoc -> Bool
    fitsR Int
    p Int
    m (Int
    p Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    i) SimpleDoc
    x
                            | Bool
    otherwise  = Bool
    True
    fitsR Int
    p Int
    m Int
    w (SSGR [SGR]
    _ SimpleDoc
    x)               = Int -> Int -> Int -> SimpleDoc -> Bool
    fitsR Int
    p Int
    m Int
    w SimpleDoc
    x

    -----------------------------------------------------------
    -- renderCompact: renders documents without indentation
    --  fast and fewer characters output, good for machines
    -----------------------------------------------------------

    -- | @(renderCompact x)@ renders document @x@ without adding any
    -- indentation. Since no \'pretty\' printing is involved, this
    -- renderer is very fast. The resulting output contains fewer
    -- characters than a pretty printed version and can be used for output
    -- that is read by other programs.
    --
    -- This rendering function does not add any colorisation information.
    renderCompact :: Doc -> SimpleDoc
    renderCompact :: Doc -> SimpleDoc
    renderCompact Doc
    x
        = Int -> [Doc] -> SimpleDoc
    scan Int
    0 [Doc
    x]
        where
          scan :: Int -> [Doc] -> SimpleDoc
    scan Int
    k []     = SimpleDoc
    SEmpty
          scan Int
    k (Doc
    d:[Doc]
    ds) = case Doc
    d of
                            Doc
    Fail                    -> SimpleDoc
    SFail
                            Doc
    Empty                   -> Int -> [Doc] -> SimpleDoc
    scan Int
    k [Doc]
    ds
                            Char Char
    c                  -> let k' :: Int
    k' = Int
    kInt -> Int -> Int
    forall a. Num a => a -> a -> a
    +Int
    1 in Int -> SimpleDoc -> SimpleDoc
    forall a b. a -> b -> b
    seq Int
    k' (Char -> SimpleDoc -> SimpleDoc
    SChar Char
    c (Int -> [Doc] -> SimpleDoc
    scan Int
    k' [Doc]
    ds))
                            Text Int
    l String
    s                -> let k' :: Int
    k' = Int
    kInt -> Int -> Int
    forall a. Num a => a -> a -> a
    +Int
    l in Int -> SimpleDoc -> SimpleDoc
    forall a b. a -> b -> b
    seq Int
    k' (Int -> String -> SimpleDoc -> SimpleDoc
    SText Int
    l String
    s (Int -> [Doc] -> SimpleDoc
    scan Int
    k' [Doc]
    ds))
                            FlatAlt Doc
    x Doc
    _             -> Int -> [Doc] -> SimpleDoc
    scan Int
    k (Doc
    xDoc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :[Doc]
    ds)
                            Doc
    Line                    -> Int -> SimpleDoc -> SimpleDoc
    SLine Int
    0 (Int -> [Doc] -> SimpleDoc
    scan Int
    0 [Doc]
    ds)
                            Cat Doc
    x Doc
    y                 -> Int -> [Doc] -> SimpleDoc
    scan Int
    k (Doc
    xDoc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :Doc
    yDoc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :[Doc]
    ds)
                            Nest Int
    j Doc
    x                -> Int -> [Doc] -> SimpleDoc
    scan Int
    k (Doc
    xDoc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :[Doc]
    ds)
                            Union Doc
    x Doc
    y               -> Int -> [Doc] -> SimpleDoc
    scan Int
    k (Doc
    yDoc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :[Doc]
    ds)
                            Column Int -> Doc
    f                -> Int -> [Doc] -> SimpleDoc
    scan Int
    k (Int -> Doc
    f Int
    kDoc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :[Doc]
    ds)
                            Columns Maybe Int -> Doc
    f               -> Int -> [Doc] -> SimpleDoc
    scan Int
    k (Maybe Int -> Doc
    f Maybe Int
    forall a. Maybe a
    NothingDoc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :[Doc]
    ds)
                            Nesting Int -> Doc
    f               -> Int -> [Doc] -> SimpleDoc
    scan Int
    k (Int -> Doc
    f Int
    0Doc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :[Doc]
    ds)
                            Color ConsoleLayer
    _ ColorIntensity
    _ Color
    _ Doc
    x           -> Int -> [Doc] -> SimpleDoc
    scan Int
    k (Doc
    xDoc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :[Doc]
    ds)
                            Intensify ConsoleIntensity
    _ Doc
    x           -> Int -> [Doc] -> SimpleDoc
    scan Int
    k (Doc
    xDoc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :[Doc]
    ds)
                            Italicize Bool
    _ Doc
    x           -> Int -> [Doc] -> SimpleDoc
    scan Int
    k (Doc
    xDoc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :[Doc]
    ds)
                            Underline Underlining
    _ Doc
    x           -> Int -> [Doc] -> SimpleDoc
    scan Int
    k (Doc
    xDoc -> [Doc] -> [Doc]
    forall a. a -> [a] -> [a]
    :[Doc]
    ds)
                            RestoreFormat Maybe (ColorIntensity, Color)
    _ Maybe (ColorIntensity, Color)
    _ Maybe ConsoleIntensity
    _ Maybe Bool
    _ Maybe Underlining
    _ -> Int -> [Doc] -> SimpleDoc
    scan Int
    k [Doc]
    ds

    -----------------------------------------------------------
    -- Displayers:  displayS and displayIO
    -----------------------------------------------------------

    -- | @(displayS simpleDoc)@ takes the output @simpleDoc@ from a
    -- rendering function and transforms it to a 'ShowS' type (for use in
    -- the 'Show' class).
    --
    -- > showWidth :: Int -> Doc -> String
    -- > showWidth w x   = displayS (renderPretty 0.4 w x) ""
    --
    -- ANSI color information will be discarded by this function unless
    -- you are running on a Unix-like operating system. This is due to
    -- a technical limitation in Windows ANSI support.
    displayS :: SimpleDoc -> ShowS
    displayS :: SimpleDoc -> ShowS
    displayS SimpleDoc
    SFail              = String -> ShowS
    forall a. HasCallStack => String -> a
    error (String -> ShowS) -> String -> ShowS
    forall a b. (a -> b) -> a -> b
    $ String
    "@SFail@ can not appear uncaught in a " String -> ShowS
    forall a. [a] -> [a] -> [a]
    ++
                                  String
    "rendered @SimpleDoc@"
    displayS SimpleDoc
    SEmpty             = ShowS
    forall a. a -> a
    id
    displayS (SChar Char
    c SimpleDoc
    x)        = Char -> ShowS
    showChar Char
    c ShowS -> ShowS -> ShowS
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . SimpleDoc -> ShowS
    displayS SimpleDoc
    x
    displayS (SText Int
    l String
    s SimpleDoc
    x)      = String -> ShowS
    showString String
    s ShowS -> ShowS -> ShowS
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . SimpleDoc -> ShowS
    displayS SimpleDoc
    x
    displayS (SLine Int
    i SimpleDoc
    x)        = String -> ShowS
    showString (Char
    '\n'Char -> ShowS
    forall a. a -> [a] -> [a]
    :Int -> String
    indentation Int
    i) ShowS -> ShowS -> ShowS
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . SimpleDoc -> ShowS
    displayS SimpleDoc
    x
    displayS (SSGR [SGR]
    s SimpleDoc
    x)         = String -> ShowS
    showString ([SGR] -> String
    setSGRCode [SGR]
    s) ShowS -> ShowS -> ShowS
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . SimpleDoc -> ShowS
    displayS SimpleDoc
    x

    -- | @(displayIO handle simpleDoc)@ writes @simpleDoc@ to the file
    -- handle @handle@. This function is used for example by 'hPutDoc':
    --
    -- > hPutDoc handle doc  = displayIO handle (renderPretty 0.4 80 doc)
    --
    -- Any ANSI colorisation in @simpleDoc@ will be output.
    displayIO :: Handle -> SimpleDoc -> IO ()
    displayIO :: Handle -> SimpleDoc -> IO ()
    displayIO Handle
    handle SimpleDoc
    simpleDoc
        = SimpleDoc -> IO ()
    display SimpleDoc
    simpleDoc
        where
          display :: SimpleDoc -> IO ()
    display SimpleDoc
    SFail         = String -> IO ()
    forall a. HasCallStack => String -> a
    error (String -> IO ()) -> String -> IO ()
    forall a b. (a -> b) -> a -> b
    $ String
    "@SFail@ can not appear uncaught in a " String -> ShowS
    forall a. [a] -> [a] -> [a]
    ++
                                  String
    "rendered @SimpleDoc@"
          display SimpleDoc
    SEmpty         = () -> IO ()
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()
          display (SChar Char
    c SimpleDoc
    x)    = do{ Handle -> Char -> IO ()
    hPutChar Handle
    handle Char
    c; SimpleDoc -> IO ()
    display SimpleDoc
    x}
          display (SText Int
    l String
    s SimpleDoc
    x)  = do{ Handle -> String -> IO ()
    hPutStr Handle
    handle String
    s; SimpleDoc -> IO ()
    display SimpleDoc
    x}
          display (SLine Int
    i SimpleDoc
    x)    = do{ Handle -> String -> IO ()
    hPutStr Handle
    handle (Char
    '\n'Char -> ShowS
    forall a. a -> [a] -> [a]
    :Int -> String
    indentation Int
    i); SimpleDoc -> IO ()
    display SimpleDoc
    x}
          display (SSGR [SGR]
    s SimpleDoc
    x)     = do{ Handle -> [SGR] -> IO ()
    hSetSGR Handle
    handle [SGR]
    s; SimpleDoc -> IO ()
    display SimpleDoc
    x}

    -----------------------------------------------------------
    -- default pretty printers: show, putDoc and hPutDoc
    -----------------------------------------------------------
    instance Show Doc where
      showsPrec :: Int -> Doc -> ShowS
    showsPrec Int
    d Doc
    doc       = SimpleDoc -> ShowS
    displayS (Float -> Int -> Doc -> SimpleDoc
    renderPretty Float
    0.4 Int
    80 Doc
    doc)

    -- | The action @(putDoc doc)@ pretty prints document @doc@ to the
    -- standard output, with a page width of 80 characters and a ribbon
    -- width of 32 characters.
    --
    -- > main :: IO ()
    -- > main = do{ putDoc (text "hello" <+> text "world") }
    --
    -- Which would output
    --
    -- @
    -- hello world
    -- @
    --
    -- Any ANSI colorisation in @doc@ will be output.
    putDoc :: Doc -> IO ()
    putDoc :: Doc -> IO ()
    putDoc Doc
    doc              = Handle -> Doc -> IO ()
    hPutDoc Handle
    stdout Doc
    doc

    -- | @(hPutDoc handle doc)@ pretty prints document @doc@ to the file
    -- handle @handle@ with a page width of 80 characters and a ribbon
    -- width of 32 characters.
    --
    -- > main = do{ handle <- openFile "MyFile" WriteMode
    -- >          ; hPutDoc handle (vcat (map text
    -- >                            ["vertical","text"]))
    -- >          ; hClose handle
    -- >          }
    --
    -- Any ANSI colorisation in @doc@ will be output.
    hPutDoc :: Handle -> Doc -> IO ()
    hPutDoc :: Handle -> Doc -> IO ()
    hPutDoc Handle
    handle Doc
    doc  = Handle -> SimpleDoc -> IO ()
    displayIO Handle
    handle (Float -> Int -> Doc -> SimpleDoc
    renderPretty Float
    0.4 Int
    80 Doc
    doc)

    -----------------------------------------------------------
    -- insert spaces
    -- "indentation" used to insert tabs but tabs seem to cause
    -- more trouble than they solve :-)
    -----------------------------------------------------------
    spaces :: Int -> String
    spaces :: Int -> String
    spaces Int
    n        | Int
    n Int -> Int -> Bool
    forall a. Ord a => a -> a -> Bool
    <= Int
    0    = String
    ""
                    | Bool
    otherwise = Int -> Char -> String
    forall a. Int -> a -> [a]
    replicate Int
    n Char
    ' '

    indentation :: Int -> String
    indentation :: Int -> String
    indentation Int
    n   = Int -> String
    spaces Int
    n

    --indentation n   | n >= 8    = '\t' : indentation (n-8)
    --                | otherwise = spaces n

    --  LocalWords:  PPrint combinators Wadler Wadler's encloseSep