funclang series5: Prettified test functions so that the test result is more readable.

funclang-taddeus/series5/ass12.ml

@@ -45,7 +45,13 @@ let rec expr2string =
                              ^ " then " ^ expr2string(e1)
                              ^ " else " ^ expr2string(e2)
     | Fun (arg, e) -> "fun " ^ arg ^ " -> " ^ expr2string(e)
-    | FunAp (e1, e2) -> "(" ^ expr2string(e1) ^ " " ^ expr2string(e2) ^ ")"
+    | FunAp (e1, e2) ->
+        (* Add parenthesis around argument when needed *)
+        let eval_e2 = expr2string(e2) in
+        let eval_e2 = (if (String.get eval_e2 0) != '('
+                          && String.contains eval_e2 ' '
+                       then "(" ^ eval_e2 ^ ")" else eval_e2) in
+        "(" ^ expr2string(e1) ^ " " ^ eval_e2 ^ ")"
     | Let (var, e1, e2) -> "let " ^ var ^ " = " ^ expr2string(e1)
                            ^ " in " ^ expr2string(e2)
     | LetRec (var, e1, e2) -> "let rec " ^ var ^ " = " ^ expr2string(e1)

funclang-taddeus/series5/test.ml

-#use "ass13.ml";;
-
-(* let a = 1 in b *)
-print_endline (expr2string (Let ("a", (Num 1), (Var "b"))));;
-
-(* a + 3 *)
-print_endline (expr2string (BinopAp (Add, Var "a", Num 3)));;
-
-(* -a *)
-print_endline (expr2string (MonopAp (Neg, Var "a")));;
-
-let show_freevars e =
-    let free = match freevars e with
+#use "ass13.ml"
+
+let test tested_method e expect yield =
+    if yield = expect then
+        print_endline "SUCCESS"
+    else
+        Printf.printf "FAILURE: Method:   %s
+         Input:    %s
+         Expected: %s
+         Got:      %s\n"
+         tested_method (expr2string e) expect yield
+
+let test_expr2string expect e = test "expr2string" e expect (expr2string e)
+let test_freevars expect e =
+    let yield = match freevars e with
           [] -> ""
         | [x] -> x
         | h::t -> List.fold_left (fun a b -> a ^ ", " ^ b) h t
     in
-    print_endline ("\nFree variables in:\n" ^ (expr2string e)
-                   ^ "\nare: [" ^ free ^ "]")
-;;
+    test "freevars" e expect yield
+let test_eval expect e = test "eval" e expect (expr2string (eval e));;
+
+test_expr2string "let a = 1 in b" (Let ("a", (Num 1), (Var "b")));;
+test_expr2string "a + 3" (BinopAp (Add, Var "a", Num 3));;
+test_expr2string "-a" (MonopAp (Neg, Var "a"));;
+test_expr2string "a * 3" (BinopAp (Mul, Var "a", Num 3));;
 
-(* Write the expressions of assignment series 1 in our data types *)
 let l arg body = Fun (arg, body);;
 let app func arg = FunAp (func, arg);;
 
+(* Define resursive factorial function for test usage *)
+let fac =
+    let eq = BinopAp (Eq, Var "n", Num 0) in
+    let sub = BinopAp (Sub, Var "n", Num 1) in
+    let mul = BinopAp (Mul, Var "n", app (Var "fac") sub) in
+    let body = Cond (eq, Num 1, mul) in
+    LetRec ("fac", Fun ("n", body), Var "fac");;
+
+test_expr2string ("let rec fac = fun n -> if n = 0 then 1 else "
+                  ^ "n * (fac (n - 1)) in fac") fac;;
+
+(* Write the expressions of assignment series 1 in our data types *)
 let ass1a =
     let c = Var "c" in
     let bcc = l "b" (l "c" c) in
@@ -47,46 +64,20 @@ let ass1b =
     let c = Var "c" in
     (app (app (app (app uvw xyz) a) b) c);;
 
-(* [a] *)
-show_freevars (Fun ("b", (BinopAp (Add, Var "a", Num 3))));;
-
-(* [] *)
-show_freevars (Fun ("a", (BinopAp (Add, Var "a", Num 3))));;
+test_freevars "a" (Fun ("b", (BinopAp (Add, Var "a", Num 3))));;
+test_freevars "" (Fun ("a", (BinopAp (Add, Var "a", Num 3))));;
+test_freevars "" ass1a;;
+test_freevars "a, b, c" ass1b;;
 
-let l arg body = Fun (arg, body);;
-let app f e = FunAp (f, e);;
-
-(* [] *)
-show_freevars ass1a;;
-
-(* [a, b, c] *)
-show_freevars ass1b;;
-
-let show_eval e =
-    print_endline ("\nEvaluation of:\n" ^ (expr2string e)
-                   ^ "\nis:\n" ^ (expr2string (eval e)))
-;;
-
-(* -5 *)
-show_eval (BinopAp (Sub, Num 4, Num 9));;
+test_eval "-5" (BinopAp (Sub, Num 4, Num 9));;
+test_eval "false" (BinopAp (Lt, Num 6, Num 5));;
+test_eval "true" (BinopAp (Or, Bool true, Bool false));;
+test_eval "fun u -> fun w -> fun a -> a" ass1a;;
+test_eval "(a (b c))" ass1b;;
+test_eval "c + b" (Let ("a", Var "c", (BinopAp (Add, Var "a", Var "b"))));;
 
-(* 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;;
-
-(* (a (b c)) *)
-show_eval ass1b;;
-
-(* fun y' -> fun z -> ((y y') z) *)
 let x = Var "x" in
 let y = Var "y" in
 let z = Var "z" in
-show_eval (app (l "x" (l "y" (l "z" (app (app x y) z)))) y);;
-
-(* c + b *)
-show_eval (Let ("a", Var "c", (BinopAp (Add, Var "a", Var "b"))));;
+test_eval "fun y' -> fun z -> ((y y') z)"
+    (app (l "x" (l "y" (l "z" (app (app x y) z)))) y);;