| Copyright | © 2015–2017 Megaparsec contributors © 2007 Paolo Martini © 1999–2001 Daan Leijen |
|---|---|
| License | FreeBSD |
| Maintainer | Mark Karpov <markkarpov@opmbx.org> |
| Stability | experimental |
| Portability | portable |
| Safe Haskell | Safe |
| Language | Haskell2010 |
Text.Megaparsec.Combinator
Description
Commonly used generic combinators. Note that all combinators works with
any Alternative instances.
- between :: Applicative m => m open -> m close -> m a -> m a
- choice :: (Foldable f, Alternative m) => f (m a) -> m a
- count :: Applicative m => Int -> m a -> m [a]
- count' :: Alternative m => Int -> Int -> m a -> m [a]
- eitherP :: Alternative m => m a -> m b -> m (Either a b)
- endBy :: Alternative m => m a -> m sep -> m [a]
- endBy1 :: Alternative m => m a -> m sep -> m [a]
- manyTill :: Alternative m => m a -> m end -> m [a]
- someTill :: Alternative m => m a -> m end -> m [a]
- option :: Alternative m => a -> m a -> m a
- sepBy :: Alternative m => m a -> m sep -> m [a]
- sepBy1 :: Alternative m => m a -> m sep -> m [a]
- sepEndBy :: Alternative m => m a -> m sep -> m [a]
- sepEndBy1 :: Alternative m => m a -> m sep -> m [a]
- skipMany :: Alternative m => m a -> m ()
- skipSome :: Alternative m => m a -> m ()
Documentation
between :: Applicative m => m open -> m close -> m a -> m a Source #
between open close p parses open, followed by p and close.
Returns the value returned by p.
braces = between (symbol "{") (symbol "}")choice :: (Foldable f, Alternative m) => f (m a) -> m a Source #
choice ps tries to apply the parsers in the list ps in order,
until one of them succeeds. Returns the value of the succeeding parser.
count :: Applicative m => Int -> m a -> m [a] Source #
count n p parses n occurrences of p. If n is smaller or
equal to zero, the parser equals to return []. Returns a list of n
values.
count' :: Alternative m => Int -> Int -> m a -> m [a] Source #
count' m n p parses from m to n occurrences of p. If n is
not positive or m > n, the parser equals to return []. Returns a list
of parsed values.
Please note that m may be negative, in this case effect is the same
as if it were equal to zero.
eitherP :: Alternative m => m a -> m b -> m (Either a b) Source #
Combine two alternatives.
Since: 4.4.0
endBy :: Alternative m => m a -> m sep -> m [a] Source #
endBy p sep parses zero or more occurrences of p, separated
and ended by sep. Returns a list of values returned by p.
cStatements = cStatement `endBy` semicolon
endBy1 :: Alternative m => m a -> m sep -> m [a] Source #
endBy1 p sep parses one or more occurrences of p, separated
and ended by sep. Returns a list of values returned by p.
manyTill :: Alternative m => m a -> m end -> m [a] Source #
manyTill p end applies parser p zero or more times until
parser end succeeds. Returns the list of values returned by p. This
parser can be used to scan comments:
simpleComment = string "<!--" >> manyTill anyChar (string "-->")
someTill :: Alternative m => m a -> m end -> m [a] Source #
someTill p end works similarly to manyTill p end, but p should
succeed at least once.
option :: Alternative m => a -> m a -> m a Source #
option x p tries to apply parser p. If p fails without
consuming input, it returns the value x, otherwise the value returned
by p.
priority = option 0 (digitToInt <$> digitChar)
sepBy :: Alternative m => m a -> m sep -> m [a] Source #
sepBy p sep parses zero or more occurrences of p, separated
by sep. Returns a list of values returned by p.
commaSep p = p `sepBy` comma
sepBy1 :: Alternative m => m a -> m sep -> m [a] Source #
sepBy1 p sep parses one or more occurrences of p, separated
by sep. Returns a list of values returned by p.
sepEndBy :: Alternative m => m a -> m sep -> m [a] Source #
sepEndBy p sep parses zero or more occurrences of p,
separated and optionally ended by sep. Returns a list of values
returned by p.
sepEndBy1 :: Alternative m => m a -> m sep -> m [a] Source #
sepEndBy1 p sep parses one or more occurrences of p,
separated and optionally ended by sep. Returns a list of values
returned by p.
skipMany :: Alternative m => m a -> m () Source #
skipMany p applies the parser p zero or more times, skipping
its result.
space = skipMany spaceChar
skipSome :: Alternative m => m a -> m () Source #
skipSome p applies the parser p one or more times, skipping
its result.