Data.Attoparsec.Char8

Simple, efficient, character-oriented parser combinators for lazy ByteString strings, loosely based on the Parsec library.

Note: This module is intended for parsing text that is represented using an 8-bit character set, e.g. ASCII or ISO-8859-15. It does not deal with character encodings, multibyte characters, or wide characters. Any attempts to use characters above code point 255 will give wrong answers.

Parser types

type ParseError = String

A description of a parsing error.

data Parser a

Instances

Monad Parser

Functor Parser

MonadFix Parser

MonadPlus Parser

Applicative Parser

Alternative Parser

Running parsers

parse

Arguments

:: Parser a

parser to run

-> ByteString

input to parse

-> (ByteString, Either ParseError a)

Run a parser.

parseAt

Arguments

:: Parser a

parser to run

-> ByteString

input to parse

-> Int64

offset to count input from

-> (ByteString, Either ParseError (a, Int64))

Run a parser. The Int64 value is used as a base to count the number of bytes consumed.

parseTest :: Show a => Parser a -> ByteString -> IO ()

Try out a parser, and print its result.

Combinators

(<?>)

Arguments

:: Parser a

-> String

the name to use if parsing fails

-> Parser a

Name the parser, in case failure occurs.

try :: Parser a -> Parser a

Attempt a parse, but do not consume any input if the parse fails.

Parsing individual characters

anyChar :: Parser Char

char :: Char -> Parser Char

Match a specific character.

digit :: Parser Char

letter :: Parser Char

notChar :: Char -> Parser Char

Match any character except the given one.

space :: Parser Char

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

Character parser.

Character classes

inClass :: String -> Char -> Bool

Match any character in a set.

 vowel = inClass "aeiou"

Range notation is supported.

 halfAlphabet = inClass "a-nA-N"

To add a literal '-' to a set, place it at the beginning or end of the string.

notInClass :: String -> Char -> Bool

Match any character not in a set.

Efficient string handling

string :: ByteString -> Parser ByteString

Match a literal string exactly.

stringCI :: ByteString -> Parser ByteString

Satisfy a literal string, ignoring case.

skipSpace :: Parser ()

Skip over white space.

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

Skip over characters while the predicate succeeds.

takeAll :: Parser ByteString

Return all of the remaining input as a single string.

takeCount :: Int -> Parser ByteString

Return exactly the given number of bytes. If not enough are available, fail.

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

Consume characters while the predicate fails.

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

Consume characters while the predicate succeeds.

takeWhile1 :: (Char -> Bool) -> Parser ByteString

Combinators

match :: Parser a -> Parser ByteString

Parse some input with the given parser, and return the input it consumed as a string.

notEmpty :: Parser ByteString -> Parser ByteString

Test that a parser returned a non-null ByteString.

Text parsing

endOfLine :: Parser ()

Match the end of a line. This may be any of a newline character, a carriage return character, or a carriage return followed by a newline.

Numeric parsers

int :: Parser Int

Parse an integer. The position counter is not updated.

integer :: Parser Integer

Parse an integer. The position counter is not updated.

double :: Parser Double

Parse a Double. The position counter is not updated.

State observation functions

endOfInput :: Parser ()

Succeed if we have reached the end of the input string.

getConsumed :: Parser Int64

Get number of bytes consumed so far.

getInput :: Parser ByteString

Get remaining input.

lookAhead :: Parser a -> Parser a

Apply a parser without consuming any input.

Combinators

module Data.Attoparsec.Combinator