Text.ParserCombinators.Poly.ByteStringChar · polyparse-1.13

The Parser datatype

3 declarations

newtypenewtype Parser a

This Parser datatype is a specialised parsing monad with error reporting. Whereas the standard version can be used for arbitrary token types, this version is specialised to ByteString input only.

Constructors

P (ByteString -> Result ByteString a)

Instances7Monad, Functor, MonadFail, Applicative, Alternative, Commitment, …

Monad ParserDefined in polyparse-1.13 · Text.ParserCombinators.Poly.ByteStringChar
Functor ParserDefined in polyparse-1.13 · Text.ParserCombinators.Poly.ByteStringChar
MonadFail ParserDefined in polyparse-1.13 · Text.ParserCombinators.Poly.ByteStringChar
Applicative ParserDefined in polyparse-1.13 · Text.ParserCombinators.Poly.ByteStringChar
Alternative ParserDefined in polyparse-1.13 · Text.ParserCombinators.Poly.ByteStringChar
Commitment ParserDefined in polyparse-1.13 · Text.ParserCombinators.Poly.ByteStringChar
PolyParse ParserDefined in polyparse-1.13 · Text.ParserCombinators.Poly.ByteStringChar

datadata Result z a

#

A return type like Either, that distinguishes not only between right and wrong answers, but also has commitment, so that a failure cannot be undone. This should only be used for writing very primitive parsers - really it is an internal detail of the library. The z type is the remaining unconsumed input.

Constructors

Instances1Functor

Functor (Result z)Defined in polyparse-1.13 · Text.ParserCombinators.Poly.Result

valuerunParser :: Parser a -> ByteString -> (Either String a, ByteString)

#

Apply a parser to an input token sequence.

Basic parsers

valuenext :: Parser Char

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Simply return the next token in the input tokenstream.

valueeof :: Parser ()

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Succeed if the end of file/input has been reached, fail otherwise.

valuesatisfy :: (Char -> Bool) -> Parser Char

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Return the next token if it satisfies the given predicate.

valueonFail :: Parser a -> Parser a -> Parser a

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p onFail q means parse p, unless p fails, in which case parse q instead. Can be chained together to give multiple attempts to parse something. (Note that q could itself be a failing parser, e.g. to change the error message from that defined in p to something different.) However, a severe failure in p cannot be ignored.

Derived parsers (but implemented more efficiently)

valuemanySatisfy :: (Char -> Bool) -> Parser ByteString

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manySatisfy p is a more efficient fused version of many (satisfy p)

valuemany1Satisfy :: (Char -> Bool) -> Parser ByteString

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many1Satisfy p is a more efficient fused version of many1 (satisfy p)

Re-parsing

valuereparse :: ByteString -> Parser ()

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Push some tokens back onto the front of the input stream and reparse. This is useful e.g. for recursively expanding macros. When the user-parser recognises a macro use, it can lookup the macro expansion from the parse state, lex it, and then stuff the lexed expansion back down into the parser.

Re-export all more general combinators

0 declarations

module Text.ParserCombinators.Poly.Base