compiler and vm: added division

lib/vm/native.ml

@@ -17,6 +17,10 @@ let of_numeric = function
   | NInt x -> Int x
   | NDouble x -> Double x
 
+let float_of_numeric = function
+  | NInt x -> float_of_int x
+  | NDouble x -> x
+
 let numeric_generic fi fd = function
   | NInt x -> (function
                | NInt y -> NInt (fi x y)
@@ -27,7 +31,8 @@ let numeric_generic fi fd = function
 let numeric_add = numeric_generic (+) (+.)
 let numeric_sub = numeric_generic (-) (-.)
 let numeric_mul = numeric_generic ( * ) ( *. )
-let numeric_div = numeric_generic ( / ) ( /. )
+let numeric_div x y =
+  NDouble ((float_of_numeric x) /. (float_of_numeric y))
 
 let builtin_print (v : Types.value ref list) =
   List.iter (fun r -> print_endline (print_value !r)) v;
@@ -41,18 +46,24 @@ let builtin_sub (vs : Types.value ref list) =
                | NInt x -> NInt (Int.neg x)
                | NDouble x -> NDouble (Float.neg x))
   | f :: rest -> of_numeric (List.fold_left numeric_sub (to_numeric !f) (List.map (fun r -> to_numeric !r) rest))
-  | [] -> failwith "invalid number of arguments for subtraction"
+  | [] -> failwith "invalid number of arguments for subtraction: 0"
 
 let builtin_mul vs =
   of_numeric (List.fold_left numeric_mul (NInt 1) (List.map (fun r -> to_numeric !r) vs))
 
+let builtin_div vs =
+  match vs with
+  | f :: [] -> of_numeric (numeric_div (NDouble 1.0) (to_numeric !f))
+  | f :: rest -> of_numeric (List.fold_left numeric_div (to_numeric !f) (List.map (fun r -> to_numeric !r) rest))
+  | [] -> failwith "invalid number of arguments for division: 0"
 
 
 let table = [|
     builtin_print;
     builtin_add;
     builtin_sub;
-    builtin_mul
+    builtin_mul;
+    builtin_div
   |]