def test_that_alternation_works():
'''
Tests that an alternation parser returns the parse results of either one
of the composed parsers.
'''
parser = str_('hello world') | str_('hello')
assert parser.loads('hello') == 'hello'
assert parser.loads('hello world') == 'hello world'
def test_that_recursion_works():
'''
Tests that a recursion parser can be constructed by usage of `Parser` and
the `parser[...] = ...` notation. Checks if the rule `p = \'b\'|\'a\'p`
works.
'''
parser = Parser()
parser[...] = str_('b') | str_('a') >> parser
assert parser.loads('b') == 'b'
assert parser.loads('ab') == ('a', 'b')
assert parser.loads('aab') == ('a', ('a', 'b'))
assert parser.loads('aaab') == ('a', ('a', ('a', 'b')))
def test_that_chaining_functions_work():
'''
Tests that the function chaining parser returns the result of the
function call with the parse result as argument.
'''
parser = str_('42')[int]
assert parser.loads('42') == 42
def test_that_repetition_works():
'''
Tests that a repetition parser returns a list of parse results.
'''
parser = +str_('abc')
try:
parser.loads('')
except ParseError:
assert True
assert parser.loads('abc') == ['abc']
assert parser.loads('abcabc') == ['abc', 'abc']
parser = ~str_('abc')
assert parser.loads('') == []
assert parser.loads('abc') == ['abc']
assert parser.loads('abcabc') == ['abc', 'abc']
def test_that_optional_works():
'''
Tests that an optional parser returns either the parse result or None.
'''
parser = -str_('hello world')
assert parser.loads('hello world') == 'hello world'
assert parser.loads('hello') is None
def test_that_string_parser_works():
'''
Tests that a string parser constructed by `str_` accepts the argument
string.
'''
parser = str_("test")
assert parser.loads("test") == "test"
try:
parser.loads("town")
except ParseError:
assert True
def test_that_concatenation_works():
'''
Tests that a concatenation parser should return a tuple of parse results
'''
parser = str_('hello') >> str_(' ') >> str_('world')
assert parser.loads('hello world') == ('hello', ' ', 'world')
'''
A Json parser.
'''
from aptwe import Parser, str_, char_, getitem, concat
from aptwe.addons import float_, int_, space_
_parser = Parser('Json')
__esc_char_ = (str_('\\') >> char_())[getitem(1)] | char_('"').inv()
_string = (str_('"') >>
(~__esc_char_)[concat] >> str_('"'))[getitem(1)] @ 'string'
_whitespace = ~space_
_dict_key = (_whitespace >> _string >> _whitespace)[getitem(1)] @ 'dict_key'
_dict_entry = (_dict_key >> str_(':') >> _parser)[getitem((0, 2))]
_dict = (str_('{') >>
(_dict_entry % str_(','))[dict] >> str_('}'))[getitem(1)] @ 'dict'
_list = (str_('[') >> _parser % str_(',') >> str_(']'))[getitem(1)] @ 'list'
_parser[...] = (
_whitespace >>
(float_ | int_ | _string | _dict | _list) >> _whitespace)[getitem(1)]
load = _parser.load
loads = _parser.loads