on_error

This method is called when a parse error is found.

ERROR_TOKEN_ID is an internal ID of token which caused error. You can get string representation of this ID by calling token_to_str.

ERROR_VALUE is a value of error token.

value_stack is a stack of symbol values. DO NOT MODIFY this object.

This method raises ParseError by default.

If this method returns, parsers enter âerror recovering modeâ.