mirror of
https://github.com/mrkkrp/megaparsec.git
synced 2024-12-18 13:51:58 +03:00
48 lines
1.4 KiB
Haskell
48 lines
1.4 KiB
Haskell
-- |
|
|
-- Module : Text.Megaparsec.Text
|
|
-- Copyright : © 2015 Megaparsec contributors
|
|
-- © 2011 Antoine Latter
|
|
-- License : BSD3
|
|
--
|
|
-- Maintainer : Mark Karpov <markkarpov@opmbx.org>
|
|
-- Stability : experimental
|
|
-- Portability : portable
|
|
--
|
|
-- Convenience definitions for working with 'Text.Text'.
|
|
|
|
module Text.Megaparsec.Text
|
|
( Parser
|
|
, GenParser
|
|
, parseFromFile )
|
|
where
|
|
|
|
import Text.Megaparsec.Error
|
|
import Text.Megaparsec.Prim
|
|
import qualified Data.Text as T
|
|
import qualified Data.Text.IO as T
|
|
|
|
-- | Different modules corresponding to various types of streams (@String@,
|
|
-- @Text@, @ByteString@) define it differently, so user can use “abstract”
|
|
-- @Parser@ type and easily change it by importing different “type
|
|
-- modules”. This one is for strict text.
|
|
|
|
type Parser = Parsec T.Text ()
|
|
|
|
-- | @GenParser@ is similar to @Parser@ but it's parametrized over user
|
|
-- state type.
|
|
|
|
type GenParser st = Parsec T.Text st
|
|
|
|
-- | @parseFromFile p filePath@ runs a lazy text parser @p@ on the
|
|
-- input read from @filePath@ using 'Data.Text.IO.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 = runParser p () fname <$> T.readFile fname
|