Define error type enum.

src/main.c

@@ -50,7 +50,13 @@ static int runFile(WrenVM* vm, const char* path)
 {
   char* source = readFile(path);
 
-  int result = wrenInterpret(vm, path, source);
+  int result;
+  switch (wrenInterpret(vm, path, source))
+  {
+    case WREN_RESULT_SUCCESS: result = 0; break;
+    case WREN_RESULT_COMPILE_ERROR: result = 65; break; // EX_DATAERR.
+    case WREN_RESULT_RUNTIME_ERROR: result = 70; break; // EX_SOFTWARE.
+  }
 
   wrenFreeVM(vm);
   free(source);
@@ -60,6 +66,9 @@ static int runFile(WrenVM* vm, const char* path)
 
 static int runRepl(WrenVM* vm)
 {
+  printf("\\\\/\"-\n");
+  printf(" \\_/   wren v0.0.0\n");
+
   for (;;)
   {
     printf("> ");

src/wren_vm.c

@@ -1029,25 +1029,24 @@ static bool runInterpreter(WrenVM* vm)
   ASSERT(0, "Should not reach end of interpret.");
 }
 
-int wrenInterpret(WrenVM* vm, const char* sourcePath, const char* source)
+WrenInterpretResult wrenInterpret(WrenVM* vm, const char* sourcePath,
+                                  const char* source)
 {
-  // TODO: Move actual error codes to main.c and return something Wren-specific
-  // from here.
-  int result = 0;
   ObjFn* fn = wrenCompile(vm, sourcePath, source);
-  if (fn != NULL)
-  {
-    WREN_PIN(vm, fn);
-    vm->fiber = wrenNewFiber(vm, (Obj*)fn);
-    WREN_UNPIN(vm);
+  if (fn == NULL) return WREN_RESULT_COMPILE_ERROR;
 
-    if (!runInterpreter(vm)) result = 70; // EX_SOFTWARE.
+  WREN_PIN(vm, fn);
+  vm->fiber = wrenNewFiber(vm, (Obj*)fn);
+  WREN_UNPIN(vm);
+
+  if (runInterpreter(vm))
+  {
+    return WREN_RESULT_SUCCESS;
   }
   else
   {
-    result = 65; // EX_DATAERR.
+    return WREN_RESULT_RUNTIME_ERROR;
   }
-  return result;
 }
 
 void wrenPinObj(WrenVM* vm, Obj* obj, PinnedObj* pinned)