expression_parser.py 文件源码

def XXXX_cast_expression(self):
        """A function returning a parser for parsing cast expressions.

        Args:
            expression: a pyparsing parser for parsing an expression to be cast.

        Returns:
            A (pyparsing) parser for parsing cast expressions.
        """
        word = pyparsing.Word(pyparsing.alphanums + '_*[]')
        nested = pyparsing.Forward().setName("nested")
        nested << pyparsing.Combine(
            pyparsing.Literal('(').suppress()
            + pyparsing.Combine(
                pyparsing.ZeroOrMore(self._integer() | word | nested))
            + pyparsing.Literal(')').suppress()
        )
        typeof_expression = (
            _OPEN_PARENTHESIS
            + pyparsing.Keyword('typeof')
            + nested("typeof_arg")
            + _CLOSE_PARENTHESIS
        )

        type_expression = (
            typeof_expression
            | nested("simple_type")
        )
        return (
            type_expression
            + ~(_PLUS | _MINUS)
            + self.expression("expression")
        ).setParseAction(self._create_cast_expression)