Add boolean, comparison, and equality functions

src/utility.c

@@ -86,16 +86,22 @@ struct ucl_object *ucl_list_nth(struct ucl_object *list, int n) {
     return node->cell.car;
 }
 
-struct ucl_object *ucl_truthy(struct ucl_object *obj) {
+bool ucl_truthy_bool(struct ucl_object *obj) {
     // TODO: Implement me better
     if (obj->type == UCL_TYPE_INT) {
-        return ucl_predicate(obj->integer);
+        return obj->integer;
     } else if (obj->type == UCL_TYPE_SYMBOL) {
-        return ucl_predicate(true);
+        return true;
     } else if (obj->type == UCL_TYPE_CELL) {
-        return ucl_predicate(obj->cell.car != NULL);
+        return obj->cell.car != NULL;
     }
-    return ucl_error_create("Unimplemented function 'ucl_truthy'");
+
+    assert(0);
+    return false;
+}
+
+struct ucl_object *ucl_truthy(struct ucl_object *obj) {
+    return ucl_predicate(ucl_truthy_bool(obj));
 }
 
 struct ucl_object *ucl_tuple_create(struct ucl_object *obj0, struct ucl_object *obj1) {
@@ -166,3 +172,35 @@ struct ucl_object *ucl_progn(struct ucl_state *state, struct ucl_object *forms)
 
     return (result == NULL) ? ucl_nil_create() : result;
 }
+
+
+struct ucl_object *ucl_equal(
+    struct ucl_object *arg0, struct ucl_object *arg1) {
+    if (arg0->type != arg1->type) {
+        return ucl_nil_create();
+    }
+
+    switch (arg0->type) {
+        case UCL_TYPE_INT:
+            return ucl_predicate(arg0->integer == arg1->integer);
+        case UCL_TYPE_SYMBOL:
+            return ucl_predicate(!strcmp(arg0->symbol, arg1->symbol));
+        case UCL_TYPE_CELL: {
+            struct ucl_object *car_equal = ucl_equal(arg0->cell.car, arg1->cell.car);
+            if (!ucl_truthy(car_equal)) {
+                return car_equal;
+            }
+            return ucl_equal(arg0->cell.cdr, arg1->cell.cdr);
+        }
+        case UCL_TYPE_BUILTIN:
+            return ucl_predicate(arg0->special == arg1->builtin);
+        case UCL_TYPE_SPECIAL:
+            return ucl_predicate(arg0->special == arg1->builtin);
+        case UCL_TYPE_STRING:
+            return ucl_predicate(!strcmp(arg0->string, arg1->string));
+        case UCL_TYPE_ERROR:
+        case UCL_TYPE_COUNT:
+            return ucl_error_create("");
+    }
+
+}