def test_that_end_of_file_parser_parsers_multiple_times(n):
parser = reduce(
lambda accu, _: chain(accu, end_of_file()),
range(0, n),
unit(True),
)
assert run_parser(chain(parser, unit(True)), "")
def test_if_a_choice_failes_in_the_middle_of_chain_it_retries_other_option(
runner
):
p = choice(
try_parser(chain(
literal('a'),
literal('a')
)),
chain(
literal('a'),
literal('b'),
)
)
assert runner(p, 'ab').value == 'b'
def test_chain_can_take_3_parsers_as_args(runner):
p = chain(
literal('a'),
literal('b'),
literal('c')
)
assert runner(p, 'abc').value == 'c'
def test_simple_failing_parser_after_n_newlines_has_linenumber_n1_in_error(
n,
runner,
):
p = chain(
literal('\n' * n),
fail('error')
)
with pytest.raises(ParsingFailed) as err:
runner(p, ('\n' * n) + 'x')
assert display_location(line=n + 1, column=0) in str(err.value)
def test_choice_should_not_retry_if_the_parser_after_choice_fails(runner):
p = choice(
literal('a'), # this should match the incomming input
literal('aa'),
)
p = chain(
p,
literal('b')
)
with pytest.raises(ParsingFailed):
runner(p, 'aab')
def test_that_end_of_file_parser_does_only_accept_empty_input(data):
if data:
with pytest.raises(ParsingFailed):
run_parser(
end_of_file(),
data,
)
else:
assert run_parser(
chain(end_of_file(), unit(True)),
data,
)
def wrapper(document):
parser = unit(True)
for character in document:
parser = chain(parser, literal(character))
return parser
def test_chain_executes_two_parsers_and_returns_result_of_second_one(runner):
p = chain(
literal('a'),
literal('b')
)
assert runner(p, 'ab').value == 'b'
def test_that_end_of_file_parser_accepts_empty_input():
assert run_parser(
chain(end_of_file(), unit(True)),
"",
)