Method test_optional_operator

Lib/test/test_peg_generator/test_pegen.py:134–173

(self)

        )

    def test_optional_operator(self) -> None:
        grammar = """
        start: sum NEWLINE
        sum: term ('+' term)?
        term: NUMBER
        """
        parser_class = make_parser(grammar)
        node = parse_string("1 + 2\n", parser_class)
        self.assertEqual(
            node,
            [
                [
                    TokenInfo(
                        NUMBER, string="1", start=(1, 0), end=(1, 1), line="1 + 2\n"
                    ),
                    [
                        TokenInfo(
                            OP, string="+", start=(1, 2), end=(1, 3), line="1 + 2\n"
                        ),
                        TokenInfo(
                            NUMBER, string="2", start=(1, 4), end=(1, 5), line="1 + 2\n"
                        ),
                    ],
                ],
                TokenInfo(
                    NEWLINE, string="\n", start=(1, 5), end=(1, 6), line="1 + 2\n"
                ),
            ],
        )
        node = parse_string("1\n", parser_class)
        self.assertEqual(
            node,
            [
                [
                    TokenInfo(NUMBER, string="1", start=(1, 0), end=(1, 1), line="1\n"),
                    None,
                ],
                TokenInfo(NEWLINE, string="\n", start=(1, 1), end=(1, 2), line="1\n"),
            ],
        )

    def test_optional_literal(self) -> None:
        grammar = """