Source code in the ocaml programming language

void myfunc_a();
float myfunc_b(int, float);
char *myfunc_c(int *, int);


external myfunc_a: unit -> unit = "caml_myfunc_a"
external myfunc_b: int -> float -> float = "caml_myfunc_b"
external myfunc_c: int array -> string = "caml_myfunc_c"


#include <caml/mlvalues.h>
#include <caml/alloc.h>
#include <mylib.h>

CAMLprim value
caml_myfunc_a(value unit) {
    myfunc_a();
    return Val_unit;
}

CAMLprim value
caml_myfunc_b(value a, value b) {
    float c = myfunc_b(Int_val(a), Double_val(b));
    return caml_copy_double(c);
}

CAMLprim value
caml_myfunc_c(value ml_array) {
    int i, len;
    int *arr;
    char *s;
    len = Wosize_val(ml_array);
    arr = malloc(len * sizeof(int));
    for (i=0; i < len; i++) {
        arr[i] = Int_val(Field(ml_array, i));
    }
    s = myfunc_c(arr, len);
    free(arr);
    return caml_copy_string(s);
}


wrap_mylib.o: wrap_mylib.c
        ocamlc -c -ccopt -I/usr/include/mylib $<

dllmylib_stubs.so: wrap_mylib.o
        ocamlmklib -o mylib_stubs $< -lmylib

mylib.mli: mylib.ml
        ocamlc -i $< > $@

mylib.cmi: mylib.mli
        ocamlc -c $<

mylib.cmo: mylib.ml mylib.cmi
        ocamlc -c $<

mylib.cma: mylib.cmo dllmylib_stubs.so
        ocamlc -a -o $@ $< -dllib -lmylib_stubs -cclib -lmylib

mylib.cmx: mylib.ml mylib.cmi
        ocamlopt -c $<

mylib.cmxa: mylib.cmx dllmylib_stubs.so
        ocamlopt -a -o $@ $< -cclib -lmylib_stubs -cclib -lmylib

clean:
        rm -f *.[oa] *.so *.cm[ixoa] *.cmxa


open Ctypes
open Foreign

let myfunc_a = foreign "myfunc_a" (void @-> returning void)
let myfunc_b = foreign "myfunc_b" (int @-> float @-> returning float)
let myfunc_c = foreign "myfunc_c" (ptr void @-> int @-> returning string)

let myfunc_c lst =
  let arr = CArray.of_list int lst in
  myfunc_c (to_voidp (CArray.start arr)) (CArray.length arr)
;;