Method test_optional_literal

Lib/test/test_peg_generator/test_pegen.py:175–205

(self)

        )

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