{- HetCATS/Haskell/Wrapper.hs

$Id$

Authors: C. Maeder

Year: 2003

extract Haskell code from String

stops at unbalanced "}"

"then" may be recognized if it is not preceded by "if"

but that's not worth the trouble, because ...

"and" is used by Haskell,

"with", "hide", "reveal", "within", "end"

may be userdefined in Haskell

-}

module Wrapper where

import Common.Lib.Parsec

import Lexer

hStuff, stuff :: GenParser Char st String

hStuff = flat $ many stuff

stuff = lineComment <|> nestComment <|> stringLit <|> charLit

<|> balanced "{}"

<|> balanced "()"

<|> balanced "[]"

<|> single (noneOf "])}")

balanced :: String -> GenParser Char st String

balanced [o, c] = char o <:> hStuff <++> string [c]

balanced _ = error "balanced"

nestComment :: GenParser Char st String

nestComment = try (string "{-") <++>

flat (many (single (noneOf "-{")

<|> try (string "-" << notFollowedBy (char '}'))

<|> nestComment

<|> string "{" ))

<++> string "-}"

lineComment, stringLit, charLit :: GenParser Char st String

lineComment = try (string "--") <++> many (noneOf "\n\r")

<++> many (oneOf "\n\r")

stringLit = char '\"' <:> flat (many (single (noneOf "\\\"")

<|> char '\\' <:> single anyChar))

<++> string "\""

charLit = try (string "'''") <|>

char '\'' <:> flat (many (single (noneOf "\\\'")

<|> char '\\' <:> single anyChar))

<++> string "\'"