179 lines
7.4 KiB
Haskell
179 lines
7.4 KiB
Haskell
{-# LANGUAGE CPP #-}
|
|
#if __GLASGOW_HASKELL__ <= 708
|
|
{-# LANGUAGE OverlappingInstances #-}
|
|
#endif
|
|
{-# LANGUAGE FlexibleInstances #-}
|
|
{-# OPTIONS_GHC -fno-warn-incomplete-patterns #-}
|
|
|
|
-- | Pretty-printer for Language.
|
|
-- Generated by the BNF converter.
|
|
|
|
module Language.Lang.PrintGrammer where
|
|
|
|
import qualified Language.Lang.AbsGrammer
|
|
import Data.Char
|
|
|
|
-- | The top-level printing method.
|
|
|
|
printTree :: Print a => a -> String
|
|
printTree = render . prt 0
|
|
|
|
type Doc = [ShowS] -> [ShowS]
|
|
|
|
doc :: ShowS -> Doc
|
|
doc = (:)
|
|
|
|
render :: Doc -> String
|
|
render d = rend 0 (map ($ "") $ d []) "" where
|
|
rend i ss = case ss of
|
|
"[" :ts -> showChar '[' . rend i ts
|
|
"(" :ts -> showChar '(' . rend i ts
|
|
"{" :ts -> showChar '{' . new (i+1) . rend (i+1) ts
|
|
"}" : ";":ts -> new (i-1) . space "}" . showChar ';' . new (i-1) . rend (i-1) ts
|
|
"}" :ts -> new (i-1) . showChar '}' . new (i-1) . rend (i-1) ts
|
|
[";"] -> showChar ';'
|
|
";" :ts -> showChar ';' . new i . rend i ts
|
|
t : ts@(p:_) | closingOrPunctuation p -> showString t . rend i ts
|
|
t :ts -> space t . rend i ts
|
|
_ -> id
|
|
new i = showChar '\n' . replicateS (2*i) (showChar ' ') . dropWhile isSpace
|
|
space t s =
|
|
case (all isSpace t', null spc, null rest) of
|
|
(True , _ , True ) -> [] -- remove trailing space
|
|
(False, _ , True ) -> t' -- remove trailing space
|
|
(False, True, False) -> t' ++ ' ' : s -- add space if none
|
|
_ -> t' ++ s
|
|
where
|
|
t' = showString t []
|
|
(spc, rest) = span isSpace s
|
|
|
|
closingOrPunctuation :: String -> Bool
|
|
closingOrPunctuation [c] = c `elem` closerOrPunct
|
|
closingOrPunctuation _ = False
|
|
|
|
closerOrPunct :: String
|
|
closerOrPunct = ")],;"
|
|
|
|
parenth :: Doc -> Doc
|
|
parenth ss = doc (showChar '(') . ss . doc (showChar ')')
|
|
|
|
concatS :: [ShowS] -> ShowS
|
|
concatS = foldr (.) id
|
|
|
|
concatD :: [Doc] -> Doc
|
|
concatD = foldr (.) id
|
|
|
|
replicateS :: Int -> ShowS -> ShowS
|
|
replicateS n f = concatS (replicate n f)
|
|
|
|
-- | The printer class does the job.
|
|
|
|
class Print a where
|
|
prt :: Int -> a -> Doc
|
|
prtList :: Int -> [a] -> Doc
|
|
prtList i = concatD . map (prt i)
|
|
|
|
instance {-# OVERLAPPABLE #-} Print a => Print [a] where
|
|
prt = prtList
|
|
|
|
instance Print Char where
|
|
prt _ s = doc (showChar '\'' . mkEsc '\'' s . showChar '\'')
|
|
prtList _ s = doc (showChar '"' . concatS (map (mkEsc '"') s) . showChar '"')
|
|
|
|
mkEsc :: Char -> Char -> ShowS
|
|
mkEsc q s = case s of
|
|
_ | s == q -> showChar '\\' . showChar s
|
|
'\\'-> showString "\\\\"
|
|
'\n' -> showString "\\n"
|
|
'\t' -> showString "\\t"
|
|
_ -> showChar s
|
|
|
|
prPrec :: Int -> Int -> Doc -> Doc
|
|
prPrec i j = if j < i then parenth else id
|
|
|
|
instance Print Integer where
|
|
prt _ x = doc (shows x)
|
|
|
|
instance Print Double where
|
|
prt _ x = doc (shows x)
|
|
|
|
instance Print Language.Lang.AbsGrammer.Name where
|
|
prt _ (Language.Lang.AbsGrammer.Name i) = doc $ showString $ i
|
|
prtList _ [x] = concatD [prt 0 x, doc (showString " ")]
|
|
prtList _ (x:xs) = concatD [prt 0 x, doc (showString " "), prt 0 xs]
|
|
|
|
instance Print Language.Lang.AbsGrammer.NumericLiteral where
|
|
prt _ (Language.Lang.AbsGrammer.NumericLiteral i) = doc $ showString $ i
|
|
|
|
instance Print Language.Lang.AbsGrammer.Module where
|
|
prt i e = case e of
|
|
Language.Lang.AbsGrammer.Module bindings -> prPrec i 0 (concatD [prt 0 bindings])
|
|
|
|
instance Print Language.Lang.AbsGrammer.Binding where
|
|
prt i e = case e of
|
|
Language.Lang.AbsGrammer.BindingDeclaration declaration -> prPrec i 0 (concatD [prt 0 declaration])
|
|
Language.Lang.AbsGrammer.BindingDefinition definition -> prPrec i 0 (concatD [prt 0 definition])
|
|
Language.Lang.AbsGrammer.BindingPragma pragma -> prPrec i 0 (concatD [doc (showString "{#"), prt 0 pragma, doc (showString "#}")])
|
|
prtList _ [] = concatD []
|
|
prtList _ [x] = concatD [prt 0 x]
|
|
prtList _ (x:xs) = concatD [prt 0 x, doc (showString ","), prt 0 xs]
|
|
|
|
instance Print Language.Lang.AbsGrammer.Declaration where
|
|
prt i e = case e of
|
|
Language.Lang.AbsGrammer.DeclarationNamed name type_ -> prPrec i 0 (concatD [prt 0 name, doc (showString ":"), prt 0 type_])
|
|
Language.Lang.AbsGrammer.DeclarationAnonymous type_ -> prPrec i 0 (concatD [prt 0 type_])
|
|
prtList _ [] = concatD []
|
|
prtList _ [x] = concatD [prt 0 x]
|
|
prtList _ (x:xs) = concatD [prt 0 x, doc (showString ","), prt 0 xs]
|
|
|
|
instance Print Language.Lang.AbsGrammer.Definition where
|
|
prt i e = case e of
|
|
Language.Lang.AbsGrammer.DefinitionNamed name expression -> prPrec i 0 (concatD [prt 0 name, doc (showString "="), prt 0 expression])
|
|
Language.Lang.AbsGrammer.DefinitionAnonymous expression -> prPrec i 0 (concatD [prt 0 expression])
|
|
prtList _ [] = concatD []
|
|
prtList _ [x] = concatD [prt 0 x]
|
|
prtList _ (x:xs) = concatD [prt 0 x, doc (showString ","), prt 0 xs]
|
|
|
|
instance Print Language.Lang.AbsGrammer.Type where
|
|
prt i e = case e of
|
|
Language.Lang.AbsGrammer.TypeName name -> prPrec i 0 (concatD [prt 0 name])
|
|
Language.Lang.AbsGrammer.TypeApplication type_1 type_2 -> prPrec i 0 (concatD [prt 0 type_1, prt 0 type_2])
|
|
Language.Lang.AbsGrammer.TypeAbstraction type_1 type_2 -> prPrec i 0 (concatD [prt 0 type_1, doc (showString "->"), prt 0 type_2])
|
|
Language.Lang.AbsGrammer.TypeImplicit declarations -> prPrec i 0 (concatD [doc (showString "{{"), prt 0 declarations, doc (showString "}}")])
|
|
Language.Lang.AbsGrammer.TypeRecord declarations -> prPrec i 0 (concatD [doc (showString "{"), prt 0 declarations, doc (showString "}")])
|
|
Language.Lang.AbsGrammer.TypeAlternative declarations -> prPrec i 0 (concatD [doc (showString "["), prt 0 declarations, doc (showString "]")])
|
|
Language.Lang.AbsGrammer.TypeParens type_ -> prPrec i 0 (concatD [doc (showString "("), prt 0 type_, doc (showString ")")])
|
|
prtList _ [x] = concatD [prt 0 x]
|
|
prtList _ (x:xs) = concatD [prt 0 x, doc (showString ","), prt 0 xs]
|
|
|
|
instance Print Language.Lang.AbsGrammer.Pragma where
|
|
prt i e = case e of
|
|
Language.Lang.AbsGrammer.Pragma names -> prPrec i 0 (concatD [prt 0 names])
|
|
|
|
instance Print [Language.Lang.AbsGrammer.Binding] where
|
|
prt = prtList
|
|
|
|
instance Print [Language.Lang.AbsGrammer.Declaration] where
|
|
prt = prtList
|
|
|
|
instance Print [Language.Lang.AbsGrammer.Definition] where
|
|
prt = prtList
|
|
|
|
instance Print [Language.Lang.AbsGrammer.Type] where
|
|
prt = prtList
|
|
|
|
instance Print [Language.Lang.AbsGrammer.Name] where
|
|
prt = prtList
|
|
|
|
instance Print Language.Lang.AbsGrammer.Expression where
|
|
prt i e = case e of
|
|
Language.Lang.AbsGrammer.ExpressionName name -> prPrec i 0 (concatD [prt 0 name])
|
|
Language.Lang.AbsGrammer.ExpressionLiteral numericliteral -> prPrec i 0 (concatD [prt 0 numericliteral])
|
|
Language.Lang.AbsGrammer.ExpressionApplication expression1 expression2 -> prPrec i 0 (concatD [prt 0 expression1, prt 0 expression2])
|
|
Language.Lang.AbsGrammer.ExpressionAbstraction expression1 expression2 -> prPrec i 0 (concatD [prt 0 expression1, doc (showString "->"), prt 0 expression2])
|
|
Language.Lang.AbsGrammer.ExpressionImplicit module_ -> prPrec i 0 (concatD [doc (showString "{{"), prt 0 module_, doc (showString "}}")])
|
|
Language.Lang.AbsGrammer.ExpressionRecord module_ -> prPrec i 0 (concatD [doc (showString "{"), prt 0 module_, doc (showString "}")])
|
|
Language.Lang.AbsGrammer.ExpressionAlternative module_ -> prPrec i 0 (concatD [doc (showString "["), prt 0 module_, doc (showString "]")])
|
|
Language.Lang.AbsGrammer.ExpressionParens expression -> prPrec i 0 (concatD [doc (showString "("), prt 0 expression, doc (showString ")")])
|
|
|