add Element.Region and Class#include

class_include.js

@@ -0,0 +1,28 @@
+/*
+
+// include mixin into a "class"
+Hash.include(Enumerable);
+
+// overwrite one of the mixin methods
+Enumerable.each = function(){ return 'foo' };
+
+// changes are reflected on all instances of the "class"
+(new Hash()).each(); // 'foo'
+
+*/
+
+Class.Methods.include = function(mixin) {
+  var fn;
+  for (var prop in mixin) {
+    // use late binding
+    this.prototype[prop] = (function(prop){
+      fn = function() {
+        return mixin[prop].apply(mixin, arguments);
+      };
+      // spoof toString
+      fn.toString = mixin[prop].toString.bind(mixin[prop]);
+      return fn;
+    })(prop);
+  }
+  return this;
+};

experimental/element_region.js

@@ -1,12 +1,6 @@
-Element.Region = Class.create({
-  initialize: function(element) {
-    this.element = $(element);
-    var offset = this.element.cumulativeOffset();
-    var dim = this.element.getDimensions();
-    this.top = offset.top;
-    this.left = offset.left;
-    this.bottom = this.top + dim.height;
-    this.right = this.left + dim.width;
+Region = Class.create({
+  initialize: function(bounds) {
+    Object.extend(this, bounds);
   },
   contains: function(other) {
     return other.left >= this.left && 
@@ -20,4 +14,18 @@ Element.Region = Class.create({
       ((other.top >= this.top && other.top <= this.bottom) ||
       (other.bottom >= this.top && other.bottom <= this.bottom));
   }
+});
+
+Element.Region = Class.create(Region, {
+  initialize: function($super, element) {
+    this.element = $(element);
+    var offset = this.element.cumulativeOffset();
+    var dim = this.element.getDimensions();
+    return $super({
+      top: offset.top,
+      left: offset.left,
+      bottom: offset.top + dim.height,
+      right: offset.left + dim.width
+    })
+  }
 });