@@ -207,8 +207,28 @@
 		string[i] ^= string[j];
 		string[j] ^= string[i];
 		string[i] ^= string[j];
 	}
 
+	return self;
+}
+
+- upper
+{
+	size_t i = length;
+
+	while (i--) 
+		string[i] = towupper(string[i]);
+
+	return self;
+}
+
+- lower
+{
+	size_t i = length;
+
+	while (i--) 
+		string[i] = towlower(string[i]);
+
 	return self;
 }
 @end