feat: add "while-not-null" test

src/vm/fzl_vm.c

@@ -208,7 +208,7 @@ void print_object(fzl_vm_object_t *obj)
       printf("<unknown>");
   }
 
-  printf(">\n");
+  printf(">");
 }
 
 void print_err_data(fzl_vm_t *vm)
@@ -435,6 +435,7 @@ int fzl_vm_run(fzl_vm_t *vm)
         fzl_vm_object_t *obj  = malloc(sizeof(fzl_vm_object_t));
         obj->values           = malloc(values_count * sizeof(fzl_value_t));
         obj->values_count     = values_count;
+        memset(obj->values, 0, values_count * sizeof(fzl_value_t));
 
         fzl_vm_env_t *current_env = vm->estack[vm->etop - 1];
         if (current_env->owned_objects_remainder <=
@@ -858,7 +859,10 @@ int fzl_vm_run(fzl_vm_t *vm)
           else if (arg.type == FZL_TYPE_NULL)
             printf("<null>\n");
           else if (arg.type == FZL_TYPE_OBJECT)
+          {
             print_object(arg.as.obj);
+            printf("\n");
+          }
         }
         else if (fn_id == FZL_BUILTIN_EXIT)
         {

tests/programs/pos_while_not_null.fzs

@@ -0,0 +1,28 @@
+class Some {
+  Some next;
+}
+
+Some l4 = new Some;
+
+Some l3 = new Some;
+l3.next = l4;
+
+Some l2 = new Some;
+l2.next = l3;
+
+Some l1 = new Some;
+l1.next = l2;
+
+Some root = new Some;
+root.next = l1;
+
+Some obj = root;
+while (obj != null)
+{
+  obj = obj.next;
+  printline("Now object is:");
+  printline(obj);
+}
+
+printline(obj);
+