polyparse-1.12: A variety of alternative parser combinator libraries.

Safe HaskellSafe
LanguageHaskell98

Text.ParserCombinators.Poly.Text

Contents

Synopsis

The Parser datatype

newtype 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 Text input only.

Constructors

P (Text -> Result Text a) 

Instances

Monad Parser # 

Methods

(>>=) :: Parser a -> (a -> Parser b) -> Parser b #

(>>) :: Parser a -> Parser b -> Parser b #

return :: a -> Parser a #

fail :: String -> Parser a #

Functor Parser # 

Methods

fmap :: (a -> b) -> Parser a -> Parser b #

(<$) :: a -> Parser b -> Parser a #

Applicative Parser # 

Methods

pure :: a -> Parser a #

(<*>) :: Parser (a -> b) -> Parser a -> Parser b #

(*>) :: Parser a -> Parser b -> Parser b #

(<*) :: Parser a -> Parser b -> Parser a #

Alternative Parser # 

Methods

empty :: Parser a #

(<|>) :: Parser a -> Parser a -> Parser a #

some :: Parser a -> Parser [a] #

many :: Parser a -> Parser [a] #

PolyParse Parser # 
Commitment Parser # 

Methods

commit :: Parser a -> Parser a #

adjustErr :: Parser a -> (String -> String) -> Parser a #

oneOf' :: [(String, Parser a)] -> Parser a #

data 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

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

Instances

Functor (Result z) # 

Methods

fmap :: (a -> b) -> Result z a -> Result z b #

(<$) :: a -> Result z b -> Result z a #

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

Apply a parser to an input token sequence.

Basic parsers

next :: Parser Char #

Simply return the next token in the input tokenstream.

eof :: Parser () #

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

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

Return the next token if it satisfies the given predicate.

onFail :: Parser a -> Parser a -> Parser a #

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 Text #

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

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

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

Re-parsing

reparse :: Text -> Parser () #

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