[Header]
open K__
open K

let test_run pgm_str =
  let pgm = Parser.program Lexer.start (Lexing.from_string pgm_str) in
  K.run (K.emptyMemory, K.emptyEnv, pgm)

let test_error_str pgm_str =
  let pgm = Parser.program Lexer.start (Lexing.from_string pgm_str) in
  try
    (try let _ =  K.run (K.emptyMemory, K.emptyEnv, pgm) in "" with
    K.Error s -> String.sub s 0 7)
  with Invalid_argument _ -> ""


[Test]
(* 1. let, assignment, arithmetic *)
test_run
"
let x := 5 in
let y := 0 in
((x := 6) - 3) * 4 + (y := x * 2) / 5 + y
"

[Value]
K.Num 14


[Test]
(* 2. branch, sequence, write *)
test_run
"
if (3 < 5) then (
  write 1;
  if (not false) then (
    write 11;
    if (20 < 10) then
      write 111
    else
      write 222
  )
  else
    write 22
)
else
  false
"

[Output]
1
11
222


[Test]
(* 3. type error in arithmetic *)
test_error_str
"
true + 2
"

[Value]
"TypeErr"


[Test]
(* 4. while + let *)
test_run
"let x := 1 in
let sum := 0 in
while (x < 11) do (
   sum := sum + x;
   x := x + 1
); sum"

[Value]
K.Num 55


[Test]
(* 5. equal + unbound in false branch *)
test_run
"
if 3 < 2 then
  x
else (
  if (false = 3) then
    y
  else
    25
)
"

[Value]
K.Num 25


[Test]
(* 6. result of assign *)
test_run
"
let x := 3 in
write x * (x := x + 1);
write (x := x + 1) * x;
if (x := 0) < x then
  write x;
  while (x := x + 1) < 3 do
    write x
else false
"

[Output]
16
20
0
1
2


[Test]
(* 7. scope *)
test_run
"
let x := 0 in
let z :=
  (let x := (x := 3; x + 1) in
   x := x + 1;
   (x := x + 1) * (let x := 2 in x := x + 1))
in
z
"

[Value]
K.Num 18


[Test]
(* 8. unbound variable *)
test_error_str
"
let y:=
  let x := 5 in
  x
in
x + y
"

[Value]
"Unbound"


[Test]
(* 9. Factorial but convoluted *)
test_run
"let n := 10 in
let prod := 1 in
let cond := true in
while (cond := (0 < n)) do (
   prod := prod * n;
   n := n - 1
);
if (false = 0) then cond := true else
prod"

[Value]
K.Num 3628800


[Test]
(* 10. GCD *)
test_run
"let n := 9168 in
let m := 1337 in
while (not (n = 0)) do (
 let r := m - (m / n) * n in
 m := n;
 n := r
);
m"

[Value]
K.Num 191