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354760202e
Close #43. The method allows to fail with arbitrary collection of messages. ‘unexpected’ is not defined in terms of ‘failure’. One consequence of this design decision is that ‘failure’ is now method of ‘MonadParsec’, while ‘unexpected’ is not.
193 lines
4.2 KiB
Haskell
193 lines
4.2 KiB
Haskell
-- |
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-- Module : Text.Megaparsec
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-- Copyright : © 2015 Megaparsec contributors
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-- © 2007 Paolo Martini
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-- © 1999–2001 Daan Leijen
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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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-- This module includes everything you need to get started writing a parser.
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--
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-- By default this module is set up to parse character data. If you'd like to
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-- parse the result of your own tokenizer you should start with the following
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-- imports:
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--
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-- > import Text.Megaparsec.Prim
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-- > import Text.Megaparsec.Combinator
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--
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-- Then you can implement your own version of 'satisfy' on top of the
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-- 'token' primitive.
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--
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-- Typical import section looks like this:
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--
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-- > import Text.Megaparsec
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-- > import Text.Megaparsec.String
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-- > -- import Text.Megaparsec.ByteString
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-- > -- import Text.Megaparsec.ByteString.Lazy
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-- > -- import Text.Megaparsec.Text
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-- > -- import Text.Megaparsec.Text.Lazy
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--
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-- As you can see the second import depends on data type you want to use as
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-- input stream. It just defines useful type-synonym @Parser@.
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--
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-- Megaparsec is capable of a lot. Apart from this standard functionality
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-- you can parse permutation phrases with "Text.Megaparsec.Perm" and even
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-- entire languages with "Text.Megaparsec.Lexer". These modules should be
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-- imported explicitly along with the two modules mentioned above.
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module Text.Megaparsec
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( -- * Running parser
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Parsec
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, ParsecT
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, runParser
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, runParser'
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, runParserT
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, runParserT'
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, parse
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, parseMaybe
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, parseTest
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, parseFromFile
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-- * Combinators
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, (A.<|>)
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-- $assocbo
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, A.many
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-- $many
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, A.some
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-- $some
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, A.optional
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-- $optional
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, unexpected
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, failure
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, (<?>)
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, label
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, hidden
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, try
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, lookAhead
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, notFollowedBy
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, eof
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, token
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, tokens
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, between
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, choice
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, count
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, count'
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, endBy
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, endBy1
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, manyTill
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, someTill
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, option
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, sepBy
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, sepBy1
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, sepEndBy
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, sepEndBy1
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, skipMany
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, skipSome
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-- Deprecated combinators
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, chainl
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, chainl1
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, chainr
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, chainr1
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-- * Character parsing
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, newline
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, crlf
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, eol
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, tab
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, space
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, controlChar
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, spaceChar
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, upperChar
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, lowerChar
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, letterChar
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, alphaNumChar
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, printChar
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, digitChar
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, octDigitChar
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, hexDigitChar
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, markChar
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, numberChar
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, punctuationChar
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, symbolChar
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, separatorChar
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, asciiChar
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, latin1Char
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, charCategory
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, char
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, char'
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, anyChar
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, oneOf
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, oneOf'
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, noneOf
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, noneOf'
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, satisfy
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, string
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, string'
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-- * Error messages
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, Message (..)
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, messageString
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, badMessage
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, ParseError
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, errorPos
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, errorMessages
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, errorIsUnknown
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-- * Textual source position
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, SourcePos
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, sourceName
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, sourceLine
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, sourceColumn
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-- * Low-level operations
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, Stream (..)
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, StorableStream (..)
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, State (..)
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, getInput
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, setInput
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, getPosition
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, setPosition
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, getTabWidth
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, setTabWidth
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, getParserState
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, setParserState
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, updateParserState )
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where
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import qualified Control.Applicative as A
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import Text.Megaparsec.Char
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import Text.Megaparsec.Combinator
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import Text.Megaparsec.Error
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import Text.Megaparsec.Pos
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import Text.Megaparsec.Prim
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-- $assocbo
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--
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-- This combinator implements choice. The parser @p \<|> q@ first applies
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-- @p@. If it succeeds, the value of @p@ is returned. If @p@ fails
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-- /without consuming any input/, parser @q@ is tried.
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--
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-- The parser is called /predictive/ since @q@ is only tried when parser @p@
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-- didn't consume any input (i.e. the look ahead is 1). This
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-- non-backtracking behaviour allows for both an efficient implementation of
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-- the parser combinators and the generation of good error messages.
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-- $many
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--
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-- @many p@ applies the parser @p@ /zero/ or more times. Returns a list of
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-- the returned values of @p@.
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--
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-- > identifier = (:) <$> letter <*> many (alphaNum <|> char '_')
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-- $some
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--
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-- @some p@ applies the parser @p@ /one/ or more times. Returns a list of
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-- the returned values of @p@.
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--
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-- > word = some letter
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-- $optional
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--
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-- @optional p@ tries to apply parser @p@. It will parse @p@ or nothing. It
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-- only fails if @p@ fails after consuming input. On success result of @p@
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-- is returned inside of 'Just', on failure 'Nothing' is returned.
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