def test_left_recursive(self) -> None:
grammar_source = """
start: expr NEWLINE
expr: ('-' term | expr '+' term | term)
term: NUMBER
foo: NAME+
bar: NAME*
baz: NAME?
"""
grammar: Grammar = parse_string(grammar_source, GrammarParser)
parser_class = generate_parser(grammar)
rules = grammar.rules
self.assertFalse(rules["start"].left_recursive)
self.assertTrue(rules["expr"].left_recursive)
self.assertFalse(rules["term"].left_recursive)
self.assertFalse(rules["foo"].left_recursive)
self.assertFalse(rules["bar"].left_recursive)
self.assertFalse(rules["baz"].left_recursive)
node = parse_string("1 + 2 + 3\n", parser_class)
self.assertEqual(node, [
[
[
[[TokenInfo(NUMBER, string="1", start=(1, 0), end=(1, 1), line="1 + 2 + 3\n")]],
TokenInfo(OP, string="+", start=(1, 2), end=(1, 3), line="1 + 2 + 3\n"),
[TokenInfo(NUMBER, string="2", start=(1, 4), end=(1, 5), line="1 + 2 + 3\n")],
],
TokenInfo(OP, string="+", start=(1, 6), end=(1, 7), line="1 + 2 + 3\n"),
[TokenInfo(NUMBER, string="3", start=(1, 8), end=(1, 9), line="1 + 2 + 3\n")],
],
TokenInfo(NEWLINE, string="\n", start=(1, 9), end=(1, 10), line="1 + 2 + 3\n"),
])
def main() -> None:
print(
f"Testing {GRAMMAR_FILE} starting at nesting depth of {INITIAL_NESTING_DEPTH}..."
)
with TemporaryDirectory() as tmp_dir:
nesting_depth = INITIAL_NESTING_DEPTH
rules, parser, tokenizer = build_parser(GRAMMAR_FILE)
python_parser = generate_parser(rules)
c_parser = generate_parser_c_extension(rules, Path(tmp_dir))
c_succeeded = True
python_succeeded = True
while c_succeeded or python_succeeded:
expr = f"{'(' * nesting_depth}0{')' * nesting_depth}"
if c_succeeded:
c_succeeded = check_nested_expr(nesting_depth, c_parser, "C")
if python_succeeded:
python_succeeded = check_nested_expr(nesting_depth,
python_parser, "Python")
nesting_depth += NESTED_INCR_AMT
sys.exit(1)
def test_left_recursive():
grammar = """
start: expr NEWLINE
expr: ('-' term | expr '+' term | term)
term: NUMBER
foo: NAME+
bar: NAME*
baz: NAME?
"""
rules = parse_string(grammar, GrammarParser).rules
parser_class = generate_parser(rules)
assert not rules['start'].left_recursive
assert rules['expr'].left_recursive
assert not rules['term'].left_recursive
assert not rules['foo'].left_recursive
assert not rules['bar'].left_recursive
assert not rules['baz'].left_recursive
node = parse_string("1 + 2 + 3\n", parser_class)
assert node == [[[[[
TokenInfo(NUMBER,
string='1',
start=(1, 0),
end=(1, 1),
line='1 + 2 + 3\n')
]],
TokenInfo(OP,
string='+',
start=(1, 2),
end=(1, 3),
line='1 + 2 + 3\n'),
[
TokenInfo(NUMBER,
string='2',
start=(1, 4),
end=(1, 5),
line='1 + 2 + 3\n')
]],
TokenInfo(OP,
string='+',
start=(1, 6),
end=(1, 7),
line='1 + 2 + 3\n'),
[
TokenInfo(NUMBER,
string='3',
start=(1, 8),
end=(1, 9),
line='1 + 2 + 3\n')
]],
TokenInfo(NEWLINE,
string='\n',
start=(1, 9),
end=(1, 10),
line='1 + 2 + 3\n')]
def test_left_recursive():
grammar = """
start: expr NEWLINE
expr: ('-' term | expr '+' term | term)
term: NUMBER
foo: NAME+
bar: NAME*
baz: NAME?
"""
grammar = parse_string(grammar, GrammarParser)
parser_class = generate_parser(grammar)
rules = grammar.rules
assert not rules["start"].left_recursive
assert rules["expr"].left_recursive
assert not rules["term"].left_recursive
assert not rules["foo"].left_recursive
assert not rules["bar"].left_recursive
assert not rules["baz"].left_recursive
node = parse_string("1 + 2 + 3\n", parser_class)
assert node == [
[
[
[[
TokenInfo(NUMBER,
string="1",
start=(1, 0),
end=(1, 1),
line="1 + 2 + 3\n")
]],
TokenInfo(OP,
string="+",
start=(1, 2),
end=(1, 3),
line="1 + 2 + 3\n"),
[
TokenInfo(NUMBER,
string="2",
start=(1, 4),
end=(1, 5),
line="1 + 2 + 3\n")
],
],
TokenInfo(OP,
string="+",
start=(1, 6),
end=(1, 7),
line="1 + 2 + 3\n"),
[
TokenInfo(NUMBER,
string="3",
start=(1, 8),
end=(1, 9),
line="1 + 2 + 3\n")
],
],
TokenInfo(NEWLINE,
string="\n",
start=(1, 9),
end=(1, 10),
line="1 + 2 + 3\n"),
]
