polyparse Source code Contents Index

Text.ParserCombinators.Poly.Lazy

Contents The Parser datatype basic parsers re-parsing Re-export all more general combinators

Synopsis

newtype Parser t a = P ([t] -> Result [t] a) data Result z a = Success z a | Failure z String | Committed (Result z a) runParser :: Parser t a -> [t] -> (a, [t]) next :: Parser t t eof :: Parser t () satisfy :: (t -> Bool) -> Parser t t reparse :: [t] -> Parser t () module Text.ParserCombinators.Poly.Base

The Parser datatype

newtype Parser t a Source

This Parser datatype is a fairly generic parsing monad with error reporting. It can be used for arbitrary token types, not just String input. (If you require a running state, use module PolyState instead) Constructors P ([t] -> Result [t] a) Instances Monad (Parser t) Functor (Parser t) PolyParse (Parser t)

data Result z a Source

A return type like Either, that distinguishes not only between right and wrong answers, but also has gradations of wrongness. This should only be used for writing very primitive parsers - really it is an internal detail of the library. Constructors Success z a Failure z String Committed (Result z a) Instances Functor (Result z)

runParser :: Parser t a -> [t] -> (a, [t]) Source

Apply a parser to an input token sequence.

basic parsers

next :: Parser t t Source

eof :: Parser t () Source

satisfy :: (t -> Bool) -> Parser t t Source

re-parsing

reparse :: [t] -> Parser t () Source

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

module Text.ParserCombinators.Poly.Base

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