{- |

Module : $Id$

Copyright : (c) Felix Reckers, Uni Bremen 2002-2004

License : GPLv2 or higher, see LICENSE.txt

Maintainer : Christian.Maeder@dfki.de

Stability : provisional

Portability : portable

a very limited Haskell-Parser based on DrIFT's Haskell-Parser

-}

module ParseFile where

import DataP

import CommandP

import ParseLib2

type Import = String

-- result: (datas, imports)

parseInputFile :: FilePath -> String -> Either String ([String], [Import])

parseInputFile fp inp = case (ds, is) of

(Left s, Left s2) -> Left (s ++ "\n" ++ s2)

(Left s, Right _) -> Left s

(Right _, Left s) -> Left s

(Right x, Right y) -> case y of

[] -> Right (x, y)

m : _ -> Right (map ((m ++ ".") ++) x, y)

where

datParser = skipUntilOff $ datadecl +++ newtypedecl

ds = case papply (parse datParser) (0, 0) ((0, 0), inp) of

[(x, _)] -> Right $ map name x

_ -> Left (fp ++ ": wrong parse (data)")

is = case papply (parse allImports) (0, -1) ((0, 0), inp) of

[(x, _)] -> Right x

_ -> Left (fp ++ ": wrong parse (imports)")

allImports :: Parser [Import]

allImports = do

symbol "module"

m <- cap

opt (skipNest (symbol "(") (symbol ")") >> return [])

symbol "where"

many (fmap (const ()) command +++ comment)

is <- many importDecl

return (m : is)

importDecl :: Parser Import

importDecl = do

symbol "import"

q <- opt (symbol "qualified")

i <- cap

a <- opt (symbol "as" >> cap)

h <- opt (symbol "hiding")

hs <- opt $ importList (symbol "(") (symbol ")")

let add s = if null s then "" else ' ' : s

return $ (if null q then "" else q ++ " ")

++ i ++ (if null a then "" else " as " ++ a)

++ add h ++ add hs

importList :: Parser String -> Parser String -> Parser String

importList start finish = let

x = finish

+++ do

l <- importList start finish

s <- x

return (l ++ s)

+++ do

c <- item

s <- x

return (c : s)

in do

s1 <- start

s2 <- x

return (s1 ++ s2)