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import inspect
import textwrap
from unittest import TestCase, main
from lark import Lark
from lark.indenter import PythonIndenter
from lark.exceptions import UnexpectedCharacters, UnexpectedToken, ParseError
valid_DEC_NUMBER = [
"0",
"000",
"0_0_0",
"4_2",
"1_0000_0000",
"123456789012345678901234567890",
]
valid_HEX_NUMBER = [
"0x_f",
"0xffff_ffff",
"0xffffffffffffffff",
"0Xffffffffffffffff",
]
valid_OCT_NUMBER = [
"0o5_7_7",
"0o_5",
"0o77777777777777777",
"0O77777777777777777",
]
valid_BIN_NUMBER = [
"0b1001_0100",
"0b_0",
"0b100000000000000000000000000000000000000000000000000000000000000000000",
"0B111111111111111111111111111111111111111111111111111111111111111111111",
]
valid_FLOAT_NUMBER = [
"1_00_00.5",
"1_00_00.5e5",
"1_00_00e5_1",
"1e1_0",
".1_4",
".1_4e1",
"1_2.5",
"3.14",
"314.",
"0.314",
"000.314",
".314",
"3e14",
"3E14",
"3e-14",
"3e+14",
"3.e14",
".3e14",
"3.1e4",
]
valid_IMAG_NUMBER = [
"0j",
"123456789012345678901234567890j",
"1_00_00j",
"1_00_00.5j",
"1_00_00e5_1j",
".1_4j",
"3_3j",
".5_6j",
"3.14j",
"314.j",
"0.314j",
"000.314j",
".314j",
"3e14j",
"3E14j",
"3e-14j",
"3e+14j",
"3.e14j",
".3e14j",
"3.1e4j",
]
valid_number = (valid_DEC_NUMBER + valid_HEX_NUMBER + valid_OCT_NUMBER +
valid_BIN_NUMBER + valid_FLOAT_NUMBER + valid_IMAG_NUMBER)
invalid_number = [
"0_",
"42_",
"1.4j_",
"0x_",
"0b1_",
"0xf_",
"0o5_",
"1_Else",
"0_b0",
"0_xf",
"0_o5",
"0_7",
"09_99",
"4_______2",
"0.1__4",
"0.1__4j",
"0b1001__0100",
"0xffff__ffff",
"0x___",
"0o5__77",
"1e1__0",
"1e1__0j",
"1_.4",
"1_.4j",
"1._4",
"1._4j",
"._5",
"._5j",
"1.0e+_1",
"1.0e+_1j",
"1.4_j",
"1.4e5_j",
"1_e1",
"1.4_e1",
"1.4_e1j",
"1e_1",
"1.4e_1",
"1.4e_1j",
"1+1.5_j_",
"1+1.5_j",
"_0",
"_42",
"_1.4j",
"_0x",
"_0b1",
"_0xf",
"_0o5",
"_1_Else",
"_0_b0",
"_0_xf",
"_0_o5",
"_0_7",
"_09_99",
"_4_______2",
"_0.1__4",
"_0.1__4j",
"_0b1001__0100",
"_0xffff__ffff",
"_0x__",
"_0o5__77",
"_1e1__0",
"_1e1__0j",
"_1_.4",
"_1_.4j",
"_1._4",
"_1._4j",
"_._5",
"_._5j",
"_1.0e+_1",
"_1.0e+_1j",
"_1.4_j",
"_1.4e5_j",
"_1_e1",
"_1.4_e1",
"_1.4_e1j",
"_1e_1",
"_1.4e_1",
"_1.4e_1j",
"_1+1.5_j",
"_1+1.5_j",
]
valid_match_statements = [
# constant and capture patterns
textwrap.dedent("""
match greeting:
case "":
print("Hello!")
case name:
print(f"Hi {name}!")
"""),
# pattern unions
textwrap.dedent("""
match something:
case 0 | 1 | 2:
print("Small number")
case [] | [_]:
print("A short sequence")
case str() | bytes():
print("Something string-like")
case _:
print("Something else")
"""),
# guards
textwrap.dedent("""
match val:
case [x, y] if x > 0 and y > 0:
return f"A pair of {x} and {y}"
case [x, *other]:
return f"A sequence starting with {x}"
case int():
return f"Some integer"
"""),
# "as" patterns
textwrap.dedent("""
match command.split():
case ["go", ("north" | "south" | "east" | "west") as direction]:
current_room = current_room.neighbor(direction)
""")
]
invalid_match_statements = [
# no cases
textwrap.dedent("""
match val:
pass
"""),
# cases not indented relative to match
textwrap.dedent("""
match val:
case x:
pass
""")
]
class TestPythonParser(TestCase):
@classmethod
def setUpClass(cls):
cls.python_parser = Lark.open_from_package(
"lark", "python.lark", ("grammars",), parser='lalr',
postlex=PythonIndenter(), start=["number", "file_input"])
def _test_parsed_is_this_terminal(self, text, terminal, start):
tree = self.python_parser.parse(text, start=start)
self.assertEqual(len(tree.children), 1)
token = tree.children[0]
self.assertEqual(token.type, terminal)
self.assertEqual(token.value, text)
def _test_parsed_is_file_containing_only_this_statement(self, text, statement):
tree = self.python_parser.parse(text, start="file_input")
self.assertEqual(len(tree.children), 1)
statement_token = tree.children[0].data
self.assertEqual(statement_token.type, "RULE")
self.assertEqual(statement_token.value, statement)
def test_DEC_NUMBER(self):
for case in valid_DEC_NUMBER:
self._test_parsed_is_this_terminal(case, "DEC_NUMBER", "number")
def test_HEX_NUMBER(self):
for case in valid_HEX_NUMBER:
self._test_parsed_is_this_terminal(case, "HEX_NUMBER", "number")
def test_OCT_NUMBER(self):
for case in valid_OCT_NUMBER:
self._test_parsed_is_this_terminal(case, "OCT_NUMBER", "number")
def test_BIN_NUMBER(self):
for case in valid_BIN_NUMBER:
self._test_parsed_is_this_terminal(case, "BIN_NUMBER", "number")
def test_FLOAT_NUMBER(self):
for case in valid_FLOAT_NUMBER:
self._test_parsed_is_this_terminal(case, "FLOAT_NUMBER", "number")
def test_IMAG_NUMBER(self):
for case in valid_IMAG_NUMBER:
self._test_parsed_is_this_terminal(case, "IMAG_NUMBER", "number")
def test_valid_number(self):
# XXX: all valid test cases should run with the above tests for numbers
for case in valid_number:
self.python_parser.parse(case, start="number") # no error
def test_invalid_number(self):
for case in invalid_number:
with self.assertRaises((UnexpectedCharacters, UnexpectedToken)):
self.python_parser.parse(case, start="number")
def test_valid_match_statement(self):
for case in valid_match_statements:
self._test_parsed_is_file_containing_only_this_statement(case, "match_stmt")
def test_invalid_match_statement(self):
for case in invalid_match_statements:
with self.assertRaises(ParseError):
self.python_parser.parse(case, start="file_input")
def test_assign_to_variable_named_match(self):
text = textwrap.dedent("""
match = re.match(pattern, string)
""")
self._test_parsed_is_file_containing_only_this_statement(text, "assign_stmt")
def test_assign_expr_with_variable_named_match(self):
text = textwrap.dedent("""
if match := re.match(pattern, string):
do_thing(match)
""")
self._test_parsed_is_file_containing_only_this_statement(text, "if_stmt")
if __name__ == '__main__':
main()
|
