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48 lines
1.4 KiB
Haskell
48 lines
1.4 KiB
Haskell
-- |
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-- Module : Text.Megaparsec.Text
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-- Copyright : © 2015 Megaparsec contributors
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-- © 2011 Antoine Latter
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-- License : BSD3
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--
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-- Maintainer : Mark Karpov <markkarpov@opmbx.org>
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-- Stability : experimental
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-- Portability : portable
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--
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-- Convenience definitions for working with 'Text.Text'.
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module Text.Megaparsec.Text
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( Parser
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, GenParser
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, parseFromFile )
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where
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import Text.Megaparsec.Error
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import Text.Megaparsec.Prim
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import qualified Data.Text as T
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import qualified Data.Text.IO as T
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-- | Different modules corresponding to various types of streams (@String@,
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-- @Text@, @ByteString@) define it differently, so user can use “abstract”
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-- @Parser@ type and easily change it by importing different “type
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-- modules”. This one is for strict text.
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type Parser = Parsec T.Text ()
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-- | @GenParser@ is similar to @Parser@ but it's parametrized over user
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-- state type.
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type GenParser st = Parsec T.Text st
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-- | @parseFromFile p filePath@ runs a lazy text parser @p@ on the
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-- input read from @filePath@ using 'Data.Text.IO.readFile'. Returns either
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-- a 'ParseError' ('Left') or a value of type @a@ ('Right').
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--
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-- > main = do
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-- > result <- parseFromFile numbers "digits.txt"
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-- > case result of
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-- > Left err -> print err
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-- > Right xs -> print (sum xs)
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parseFromFile :: Parser a -> String -> IO (Either ParseError a)
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parseFromFile p fname = runParser p () fname <$> T.readFile fname
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