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Language	Haskell98

Text.ParserCombinators.Poly.StateText

Contents

The Parser datatype
Re-export all more general combinators

Synopsis

newtype Parser s a = P (s -> Text -> Result (Text, s) a)
data Result z a
- = Success z a
- | Failure z String
- | Committed (Result z a)
runParser :: Parser s a -> s -> Text -> (Either String a, s, Text)
next :: Parser s Char
eof :: Parser s ()
satisfy :: (Char -> Bool) -> Parser s Char
onFail :: Parser s a -> Parser s a -> Parser s a
manySatisfy :: (Char -> Bool) -> Parser s Text
many1Satisfy :: (Char -> Bool) -> Parser s Text
stUpdate :: (s -> s) -> Parser s ()
stQuery :: (s -> a) -> Parser s a
stGet :: Parser s s
reparse :: Text -> Parser s ()
module Text.ParserCombinators.Poly.Base
module Control.Applicative

The Parser datatype

newtype Parser s a Source #

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 Text input only.

Constructors

P (s -> Text -> Result (Text, s) a)

Instances

Monad (Parser s) Source #
Instance details Defined in Text.ParserCombinators.Poly.StateText Methods (>>=) :: Parser s a -> (a -> Parser s b) -> Parser s b # (>>) :: Parser s a -> Parser s b -> Parser s b # return :: a -> Parser s a # fail :: String -> Parser s a #
Functor (Parser s) Source #
Instance details Defined in Text.ParserCombinators.Poly.StateText Methods fmap :: (a -> b) -> Parser s a -> Parser s b # (<$) :: a -> Parser s b -> Parser s a #
MonadFail (Parser s) Source #
Instance details Defined in Text.ParserCombinators.Poly.StateText Methods fail :: String -> Parser s a #
Applicative (Parser s) Source #
Instance details Defined in Text.ParserCombinators.Poly.StateText Methods pure :: a -> Parser s a # (<>) :: Parser s (a -> b) -> Parser s a -> Parser s b # liftA2 :: (a -> b -> c) -> Parser s a -> Parser s b -> Parser s c # (>) :: Parser s a -> Parser s b -> Parser s b # (<*) :: Parser s a -> Parser s b -> Parser s a #
Alternative (Parser s) Source #
Instance details Defined in Text.ParserCombinators.Poly.StateText Methods empty :: Parser s a # (<\|>) :: Parser s a -> Parser s a -> Parser s a # some :: Parser s a -> Parser s [a] # many :: Parser s a -> Parser s [a] #
PolyParse (Parser s) Source #
Instance details Defined in Text.ParserCombinators.Poly.StateText
Commitment (Parser s) Source #
Instance details Defined in Text.ParserCombinators.Poly.StateText Methods commit :: Parser s a -> Parser s a Source # adjustErr :: Parser s a -> (String -> String) -> Parser s a Source # oneOf' :: [(String, Parser s a)] -> Parser s a Source #

data Result z a Source #

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

Success z a
Failure z String
Committed (Result z a)

Instances

Functor (Result z) Source #
Instance details Defined in Text.ParserCombinators.Poly.Result Methods fmap :: (a -> b) -> Result z a -> Result z b # (<$) :: a -> Result z b -> Result z a #

runParser :: Parser s a -> s -> Text -> (Either String a, s, Text) Source #

Apply a parser to an input token sequence.

Basic parsers

next :: Parser s Char Source #

Simply return the next token in the input tokenstream.

eof :: Parser s () Source #

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

satisfy :: (Char -> Bool) -> Parser s Char Source #

Return the next token if it satisfies the given predicate.

onFail :: Parser s a -> Parser s a -> Parser s a Source #

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)

manySatisfy :: (Char -> Bool) -> Parser s Text Source #

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

many1Satisfy :: (Char -> Bool) -> Parser s Text Source #

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

State-handling

stUpdate :: (s -> s) -> Parser s () Source #

Update the internal state.

stQuery :: (s -> a) -> Parser s a Source #

Query the internal state.

stGet :: Parser s s Source #

Deliver the entire internal state.

Re-parsing

reparse :: Text -> Parser s () 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

module Control.Applicative