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Repeated parsers

rep(parser, min=0, max=inf) and rep1(parser): repeated parsers

A repeated parser matches repeated instances of its parser argument. It returns a list with each element being the value of one match. rep only succeeds if it matches at least min times and will only consume up to max matches. rep1 is syntactic sugar for min=1. If min=0, then rep always succeeds, returning an empty list if no matches are found.

from parsita import *

class SummationParsers(TextParsers):
    integer = reg(r'[-+]?[0-9]+') > int
    summation = integer & rep('+' >> integer) > (lambda x: sum([x[0]] + x[1]))

assert SummationParsers.summation.parse('1 + 1 + 2 + 3 + 5') == Success(12)

repsep(parser, separator, min=0, max=inf) and rep1sep(parser, separator): repeated separated parsers

A repeated separated parser matches parser separated by separator, returning a list of the values returned by parser and discarding the value of separator. repsep only succeeds if it matches at least min times and will only consume up to max matches. rep1sep is syntactic sugar for min=1. If min=0, then repsep always succeeds, returning an empty list if no matches are found.

from parsita import *

class ListParsers(TextParsers):
    integer = reg(r'[-+]?[0-9]+') > int
    my_list = '[' >> repsep(integer, ',') << ']'

assert ListParsers.my_list.parse('[1,2,3]') == Success([1, 2, 3])