An associative binary operation

One or none.

The identity of <|>

between open close p parses open , followed by p and close . Returns the value returned by p .

braces = between (symbol "{") (symbol "}")

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.

choice = asum

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.

See also: skipCount , count' .

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.

See also: skipCount , count .

Combine two alternatives.

eitherP a b = (Left <$> a) <|> (Right <$> b)

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 p sep parses one or more occurrences of p , separated and ended by sep . Returns a list of values returned by p .

many p applies the parser p zero or more times and returns a list of the values returned by p .

identifier = (:) <$> letter <*> many (alphaNumChar <|> char '_')

manyTill p end applies parser p zero or more times until parser end succeeds. Returns the list of values returned by p . Note that end result is consumed and lost. Use manyTill_ if you wish to keep it.

See also: skipMany , skipManyTill .

manyTill_ p end applies parser p zero or more times until parser end succeeds. Returns the list of values returned by p and the end result. Use manyTill if you have no need in the result of the end .

See also: skipMany , skipManyTill .

Since: 1.2.0

some p applies the parser p one or more times and returns a list of the values returned by p .

word = some letter

someTill p end works similarly to manyTill p end , but p should succeed at least once. Note that end result is consumed and lost. Use someTill_ if you wish to keep it.

someTill p end = liftM2 (:) p (manyTill p end)

See also: skipSome , skipSomeTill .

someTill_ p end works similarly to manyTill_ p end , but p should succeed at least once. Use someTill if you have no need in the result of the end .

See also: skipSome , skipSomeTill .

Since: 1.2.0

option x p tries to apply the parser p . If p fails without consuming input, it returns the value x , otherwise the value returned by p .

option x p = p <|> pure x

See also: optional .

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 p sep parses one or more occurrences of p , separated by sep . Returns a list of values returned by p .

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 p sep parses one or more occurrences of p , separated and optionally ended by sep . Returns a list of values returned by p .

skipMany p applies the parser p zero or more times, skipping its result.

See also: manyTill , skipManyTill .

skipSome p applies the parser p one or more times, skipping its result.

See also: someTill , skipSomeTill .

skipCount n p parses n occurrences of p , skipping its result. If n is smaller or equal to zero, the parser equals to return () .

See also: count , count' .

skipManyTill p end applies the parser p zero or more times skipping results until parser end succeeds. Result parsed by end is then returned.

See also: manyTill , skipMany .

skipSomeTill p end applies the parser p one or more times skipping results until parser end succeeds. Result parsed by end is then returned.

See also: someTill , skipSome .