codetranslator's Introduction

Code Translator

A Code Translator for C8, CS146.

This translate converts loops or ifs into labels, goto and simple ifs. All code and examples are in translate.hs.

ghci translate.hs to run it.

Updated

Rewritten using Monad, the old version is trans-old.hs.

Examples:

Simple While Loop with Break

int i = 0;
while (i < 100) {
  printf("%d\n", i);
  if (i == 66) break;
  ++i;
}

Write the code above into Haskell:

s2 = [Exp "int i = 0", 
    While "i < 100" 
       [Exp "printf(\"%d\\n\", i)",
        If "i == 66" [Break] [], 
        Exp "++i"]]

After translation:

*Main> ts s2
int i = 0;
L0:;
if (!(i < 100)) goto L2;
print i;
if (i == 66) goto L1;
++i;
goto L0;
L2:;
L1:;

Perfect Numbers from 1 to 10000

int i = 1;
while (i <= 10000) {
  int acc = 0;
  for (int j = 1; j < i; ++j) {
    if (i % j == 0) acc += j;
  }
  if (i == acc) printf("%d\n", i);
  ++i;
}

Write the code above into Haskell:

s5 = [Exp "int i = 1", 
    While "i <= 10000" 
       [Exp "int acc = 0", 
        (For "int j = 1" "j < i" "++j" 
           [If "i % j == 0" [Exp "acc += j"] []]), 
        (If "i == acc" [Exp "printf(\"%d\\n\", i)"] []), 
        (Exp "++i")]]

After translation:

*Main> ts s5
int i = 1;
L0:;
if (!(i <= 10000)) goto L2;
int acc = 0;
int j = 1;
L3:;
if (!(j < i)) goto L6;
if (i % j == 0) acc += j;
L4:;
++j;
goto L3;
L6:;
L5:;
if (i == acc) printf("%d\n", i);
++i;
goto L0;
L2:;
L1:;

Switch

s4 = [Exp "int i = 0", 
    Switch "i" 
       [("0", [Exp "printf(\"%d = 0\\n\", i)"]), 
        ("1", [Exp "printf(\"%d = 1\\n\", i)"]), 
        ("2", [Exp "printf(\"%d = 2\\n\", i)"])] 
       [Exp "printf(\"other\\n\")"]]

into:

*Main> ts s4
int i = 0;
if (i == 0) goto L0;
if (i == 1) goto L2;
if (i == 2) goto L4;
printf("other\n");
goto L5;
L4:;
printf("%d = 2\n", i);
L5:;
goto L3;
L2:;
printf("%d = 1\n", i);
L3:;
goto L1;
L0:;
printf("%d = 0\n", i);
L1:;