(*oops.ex*)
                    (* A simple example of oops*)

use "oops-sig";
use "oops-struct";
open oops;

(**************************************************************************)

val point_2D = defflavor (0,0);
val point_2D = defmethod "inc x" point_2D
               (fn a => let val (x:int,y:int) = a in (x+1,y) end);
val point_2D = defmethod "inc y" point_2D
               (fn a => let val (x:int,y:int) = a in (x,y+1) end);
val point_2D = defmethod "zero" point_2D 
               (fn a => (0,0));

val p2 = make_instance point_2D;
describe p2;

(**************************************************************************)

val point_3D = defflavor (0,0,0);
val point_3D = defmethod "inc x" point_3D
               (fn a => let val (x:int,y:int,z:int) = a in (x+1,y,z) end);
val point_3D = defmethod "inc y" point_3D
               (fn a => let val (x:int,y:int,z:int) = a in (x,y+1,z) end);
val point_3D = defmethod "inc z" point_3D
               (fn a => let val (x:int,y:int,z:int) = a in (x,y,z+1) end);
val point_3D = defmethod "zero" point_3D
               (fn a => (0,0,0));

val p3 = make_instance point_3D;
describe p3;

(**************************************************************************)

val var = defflavor (~999,[~999],[~999]);
val var = defmethod "reset" var
          (fn a => let val (_,_,o_d) = a in (~999,o_d,o_d) end);
val var = defmethod "instantiate" var
          (fn a => let val (_,d,o_d) = a in (hd d,tl d,o_d) end);


val con = defflavor(make_instance var,
                    (fn a => let val (x:int,y:int) = a in x=y end),
                    make_instance var,true);
val con = defmethod "check" con
          (fn a => let val (v1,r,v2,_) = a
                       val (val1,_,_) = inst_vars v1
                       val (val2,_,_) = inst_vars v2
                   in (v1,r,v2,r(val1,val2)) end);

val v1 = make_instance var and
    v2 = make_instance var and
     c = make_instance con;

setf v1 (~999,[1,2,3],[1,2,3]);
setf v2 (~999,[2,3,4],[2,3,4]);
setf c (v1,(fn a => let val (x:int,y:int) = a in x>y end),v2,true);

send "instantiate" v1;
send "instantiate" v2;
send "check" c;