ref: 5a4fb16e97cf9ed17c7d80cbfb17c7412d544da6 dir: /src/io.h/
ios *toio(sl_v v); bool isio(sl_v v) sl_purefn; sl_v io_to_str(sl_v *ps); void io_init(void); extern sl_v sl_iooutsym; extern sl_type *sl_iotype;