def optional(item, reverse=False):
from parser.parser import or_, empty
a = empty()
b = item
if reverse:
a, b = b, a
return or_(a, b)
def repeatable(item, reverse=False):
from parser.parser import forward, or_, rule
temp = forward()
a = rule(item, temp)
b = item
if reverse:
a, b = b, a
return temp.define(or_(a, b))
def max_bound(item, count, reverse=False):
from parser.parser import rule, or_
if count == 1:
return item
else:
a = rule(item, max_bound(item, count - 1, reverse))
b = item
if reverse:
a, b = b, a
return or_(a, b)
def test_predicate():
tokenizer = MorphTokenizer()
predicate = or_(normalized('московским'),
and_(gram('NOUN'), not_(gram('femn'))))
context = Context(tokenizer)
predicate = predicate.activate(context)
tokens = tokenizer('московский зоопарк')
values = [predicate(_) for _ in tokens]
assert values == [True, True]
tokens = tokenizer('московская погода')
values = [predicate(_) for _ in tokens]
assert values == [True, False]
def repeatable_optional(item,
reverse_repeatable=False,
reverse_optional=False):
from parser.parser import forward, or_, rule, empty
temp = forward()
a = empty()
b = rule(item, temp)
c = item
if reverse_repeatable:
b, c = c, b
if reverse_optional:
a, b, c = b, c, a
return temp.define(or_(a, b, c))
def test_or():
assert_bnf(or_(rule('a'), rule('b')).named('A'), "A -> 'a' | 'b'")