doc/examples/ffi/import.sml

   1 (* main.sml *)
   2
   3 (* Declare ffi to be implemented by calling the C function ffi. *)
   4 val ffi = _import "ffi" public: real array * int * int ref * char ref * int -> char;
   5 open Array
   6
   7 val size = 10
   8 val a = tabulate (size, fn i => real i)
   9 val ri = ref 0
  10 val rc = ref #"0"
  11 val n = 17
  12
  13 (* Call the C function *)
  14 val c = ffi (a, Array.length a, ri, rc, n)
  15
  16 (* FFI_INT is declared as public in ffi-import.c *)
  17 val (nGet, nSet) = _symbol "FFI_INT" public: (unit -> int) * (int -> unit);
  18
  19 val _ = print (concat [Int.toString (nGet ()), "\n"])
  20
  21 val _ =
  22    print (if c = #"c" andalso !ri = 45 andalso !rc = c
  23              then "success\n"
  24           else "fail\n")