funclang series5: Added evaluation of monops/binops.

funclang-taddeus/series5/ass13.ml

@@ -2,9 +2,44 @@
 
 (* Perform all possible beta-reductions on an expression until the normal form
  * has been reached *)
-let rec eval exp = match exp with
-      MonopAp (op, e) -> MonopAp (op, eval e)
-    | BinopAp (op, e1, e2) -> BinopAp (op, eval e1, eval e2)
+let rec eval exp =
+    let get_int_value = function
+          Num i -> i
+        | _ -> raise (Failure "Not an integer")
+    in
+    let get_bool_value = function
+          Bool b -> b
+        | _ -> raise (Failure "Not a boolean")
+    in
+    let eval_monop op a = match op with
+          Neg -> Num (- (get_int_value a))
+        | Not -> Bool (not (get_bool_value a))
+    in
+    let eval_binop op x y = match op with
+          And | Or ->
+            let a = get_bool_value x in
+            let b = get_bool_value y in
+            (match op with
+              And -> Bool (a && b)
+            | Or -> Bool (a || b))
+        | _ ->
+            let a = get_int_value x in
+            let b = get_int_value y in
+            (match op with
+              Add -> Num (a + b)
+            | Sub -> Num (a - b)
+            | Mul -> Num (a * b)
+            | Div -> Num (a / b)
+            | Eq -> Bool (a = b)
+            | Ne -> Bool (a != b)
+            | Lt -> Bool (a < b)
+            | Le -> Bool (a <= b)
+            | Gt -> Bool (a > b)
+            | Ge -> Bool (a >= b))
+    in
+    match exp with
+      MonopAp (op, e) -> eval_monop op (eval e)
+    | BinopAp (op, e1, e2) -> eval_binop op (eval e1) (eval e2)
     | Fun (x, e) -> Fun (x, eval e)
     | FunAp (Fun (x, Var y), a) when y = x -> eval a (* identity function *)
     | FunAp (Fun (y, e), a) -> (* prevent recursion *)

funclang-taddeus/series5/test.ml

-#use "ass12.ml";;
 #use "ass13.ml";;
 
 (* let a = 1 in b *)
@@ -68,6 +67,15 @@ let show_eval e =
                    ^ "\nis:\n" ^ (expr2string (eval e)))
 ;;
 
+(* -5 *)
+show_eval (BinopAp (Sub, Num 4, Num 9));;
+
+(* false *)
+show_eval (BinopAp (Lt, Num 6, Num 5));;
+
+(* true *)
+show_eval (BinopAp (Or, Bool true, Bool false));;
+
 (* fun u -> fun w -> fun a -> a *)
 show_eval ass1a;;