"%pure"[-_]"parser" return PERCENT_PURE_PARSER;
"%push-parser" return PERCENT_PUSH_PARSER;
"%push-pull-parser" return PERCENT_PUSH_PULL_PARSER;
"%require" return PERCENT_REQUIRE;
"%pure"[-_]"parser" return PERCENT_PURE_PARSER;
"%push-parser" return PERCENT_PUSH_PARSER;
"%push-pull-parser" return PERCENT_PUSH_PULL_PARSER;
"%require" return PERCENT_REQUIRE;