: static struct kwtable *rb_reserved_word(const char *str, unsigned int len)
    Ĺ len ʸ str ͽǤ
    Υե饰ơ֥֤ޤstr ͽǤʤ
    NULL ֤ޤ

        struct kwtable {
            char *name;            /* ͽ̾ */
            int id[2];             /* 0:  󽤾ܥ
                                      1:  ܥ (kIF_MOD ʤ) 
                                          Ǽ롣ʤ id[0] Ʊ  */
            enum lex_state state;  /* ܤ٤lex_state */
        };

