# -*- coding: utf-8 -*-
'Tests for issue #8: prevent definitions of non-halting parsers.'
from funcparserlib.parser import (a, many, fwd, maybe, pure, oneplus,
GrammarError, makes_progress, non_halting)
from funcparserlib.contrib.common import const
from nose.tools import ok_, assert_raises
x = a('x')
p1 = maybe(x)
p3 = maybe(x) + x
p4 = many(p3)
p5 = x | many(x)
p8 = x >> const(True)
p9 = pure(True)
def test_makes_progress():
ok_(not makes_progress(p1))
ok_(not makes_progress(p4))
ok_(not makes_progress(p5))
ok_(not makes_progress(p9))
ok_(makes_progress(p3))
ok_(makes_progress(p8))
def test_non_halting_many():
assert_raises(GrammarError, lambda: many(many(x)).parse(''))
assert_raises(GrammarError, lambda: oneplus(many(x)).parse(''))
assert_raises(GrammarError, lambda: many(p1).parse(''))
def sub(m):
if m.group('standard') is not None:
return std[m.group('standard')]
else:
return unichr(int(m.group('unicode'), 16))
return re_esc.sub(sub, s)
def make_string(n):
return unescape(n[1:-1])
# JSON Grammar
null = n('null') >> const(None)
true = n('true') >> const(True)
false = n('false') >> const(False)
number = sometok('number') >> make_number
string = sometok('string') >> make_string
value = fwd()
member = string + op_(':') + value >> tuple
object = (op_('{') + maybe(member + many(op_(',') + member)) + op_('}') >>
make_object)
array = (
op_('[') + maybe(value + many(op_(',') + value)) + op_(']') >> make_array)
value.define(null | true | false | object | array | number | string)
json_text = object | array
json_file = json_text + skip(eof)
name_parser_vars(locals())
std = {
'"': '"', '\\': '\\', '/': '/', 'b': '\b', 'f': '\f', 'n': '\n',
'r': '\r', 't': '\t',
}
def sub(m):
if m.group('standard') is not None:
return std[m.group('standard')]
else:
return unichr(int(m.group('unicode'), 16))
return re_esc.sub(sub, s)
def make_string(n):
return unescape(n[1:-1])
# JSON Grammar
null = n('null') >> const(None)
true = n('true') >> const(True)
false = n('false') >> const(False)
number = sometok('number') >> make_number
string = sometok('string') >> make_string
value = fwd()
member = string + op_(':') + value >> tuple
object = (
op_('{') +
maybe(member + many(op_(',') + member)) +
op_('}')
>> make_object)
array = (
op_('[') +
maybe(value + many(op_(',') + value)) +
op_(']')
except ZeroDivisionError:
return None
return ret
res = reduce(F, args, z)
return res
eval = unarg(eval_expr)
number = sometok('number') >> make_number
name = sometok('name') >> make_name
string = sometok('string') >> make_string
func = sometok('func') >> make_func
value = number | name | string
makeop = lambda s, f: op(s) >> const(f)
add = makeop('+', (ets.add, operator.add))
sub = makeop('-', (ets.sub, operator.sub))
mul = makeop('*', (ets.mul, operator.mul))
div = makeop('/', (ets.div, operator.div))
mul_op = mul | div
add_op = add | sub
args = fwd()
factor = fwd()
primary = value
call = func + op_('(') + args + op_(')') >> exec_func
term = factor + many(mul_op + factor ) >> eval
expr = term + many(add_op + term ) >> eval
# -*- coding: utf-8 -*-
'Tests for issue #8: prevent definitions of non-halting parsers.'
from funcparserlib.parser import (
a, many, fwd, maybe, pure, oneplus, GrammarError, makes_progress,
non_halting)
from funcparserlib.contrib.common import const
from nose.tools import ok_, assert_raises
x = a('x')
p1 = maybe(x)
p3 = maybe(x) + x
p4 = many(p3)
p5 = x | many(x)
p8 = x >> const(True)
p9 = pure(True)
def test_makes_progress():
ok_(not makes_progress(p1))
ok_(not makes_progress(p4))
ok_(not makes_progress(p5))
ok_(not makes_progress(p9))
ok_(makes_progress(p3))
ok_(makes_progress(p8))
def test_non_halting_many():
assert_raises(GrammarError, lambda: many(many(x)).parse(''))
assert_raises(GrammarError, lambda: oneplus(many(x)).parse(''))
assert_raises(GrammarError, lambda: many(p1).parse(''))
assert_raises(GrammarError, lambda: many(p5).parse(''))