# FFI

 326 void io_ffi(NgaState *vm) {
 327   switch (stack_pop(vm)) {
 328     case 0: open_library(vm); break;
 329     case 1: map_symbol(vm); break;
 330     case 2: invoke(vm); break;
 331   }
 332 }
 333
 334 void query_ffi(NgaState *vm) {
 335   stack_push(vm, 0);
 336   stack_push(vm, 8100);  /* device type 8100 */
 337 }
 338 #endif

~~~
:ffi:operation (n-?)
  DEVICE:FFI io:scan-for
    dup n:negative? [ drop 'Error:_FFI_device_not_found s:put nl ] if;
    io:invoke ;

:ffi:open (s-n)
  #0 ffi:operation ;

:ffi:map-sym (sn-n)
  #1 ffi:operation ;

:ffi:invoke (n-)
  #2 ffi:operation ;

'interface/ffi.retro
dup 'ffi:operation d:set-source
dup 'ffi:open      d:set-source
dup 'ffi:map-sym   d:set-source
dup 'ffi:invoke    d:set-source
drop
~~~