megaparsec/Text/Parsec/ByteString/Lazy.hs
Antoine Latter 0860144eff No more orphan 'Stream' instances.
The ByteString and Text instances for Stream now live in the
Prim module.
2014-04-09 15:01:24 -04:00

40 lines
1.3 KiB
Haskell

-----------------------------------------------------------------------------
-- |
-- Module : Text.Parsec.ByteString.Lazy
-- Copyright : (c) Paolo Martini 2007
-- License : BSD-style (see the LICENSE file)
--
-- Maintainer : derek.a.elkins@gmail.com
-- Stability : provisional
-- Portability : portable
--
-- Convinience definitions for working with lazy 'C.ByteString's.
--
-----------------------------------------------------------------------------
module Text.Parsec.ByteString.Lazy
( Parser, GenParser, parseFromFile
) where
import Text.Parsec.Error
import Text.Parsec.Prim
import qualified Data.ByteString.Lazy.Char8 as C
type Parser = Parsec C.ByteString ()
type GenParser t st = Parsec C.ByteString st
-- | @parseFromFile p filePath@ runs a lazy bytestring parser @p@ on the
-- input read from @filePath@ using 'ByteString.Lazy.Char8.readFile'. Returns either a 'ParseError'
-- ('Left') or a value of type @a@ ('Right').
--
-- > main = do{ result <- parseFromFile numbers "digits.txt"
-- > ; case result of
-- > Left err -> print err
-- > Right xs -> print (sum xs)
-- > }
parseFromFile :: Parser a -> String -> IO (Either ParseError a)
parseFromFile p fname
= do input <- C.readFile fname
return (runP p () fname input)