Text.ParserCombinators.Poly.Lazy

The Parser datatype

newtype Parser t a

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

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])

Apply a parser to an input token sequence.

basic parsers

next :: Parser t t

eof :: Parser t ()

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

re-parsing

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

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