{-# LANGUAGE Safe #-}

-----------------------------------------------------------------------------
-- |
-- 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 qualified Data.ByteString.Lazy.Char8 as C

import Text.Parsec.Error
import Text.Parsec.Prim

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 -> FilePath -> IO (Either ParseError a)
parseFromFile :: forall a. Parser a -> FilePath -> IO (Either ParseError a)
parseFromFile Parser a
p FilePath
fname
    = do ByteString
input <- FilePath -> IO ByteString
C.readFile FilePath
fname
         Either ParseError a -> IO (Either ParseError a)
forall (m :: * -> *) a. Monad m => a -> m a
return (Parser a -> () -> FilePath -> ByteString -> Either ParseError a
forall s t u a.
Stream s Identity t =>
Parsec s u a -> u -> FilePath -> s -> Either ParseError a
runP Parser a
p () FilePath
fname ByteString
input)