Underscore 0.4.7 is done

Rakefile

@@ -0,0 +1,9 @@
+require 'rubygems'
+require 'closure-compiler'
+
+desc "Use the Closure Compiler to compress Underscore.js"
+task :build do
+  js  = File.open('underscore.js', 'r')
+  min = Closure::Compiler.new.compile(js)
+  File.open('underscore-min.js', 'w') {|f| f.write(min) }
+end

index.html

@@ -998,7 +998,10 @@ <h2>Change Log</h2>
 
       <p>
         <b class="header">0.4.7</b><br />
-
+        Added <tt>isDate</tt>, <tt>isNaN</tt>, and <tt>isNull</tt>, for completeness.
+        Optimizations for <tt>isEqual</tt> when checking equality between Arrays
+        or Dates. <tt>_.keys</tt> is now <small><i><b>25%&ndash;2X</b></i></small> faster (depending on your
+        browser) which speeds up the functions that rely on it, such as <tt>_.each</tt>.
       </p>
 
       <p>

underscore.js

@@ -31,7 +31,7 @@
   if (typeof exports !== 'undefined') exports._ = _;
 
   // Maintain a reference to the Object prototype for quick access.
-  var oproto = Object.prototype;
+  var objPro = Object.prototype;
 
   // Current version.
   _.VERSION = '0.4.7';
@@ -395,7 +395,7 @@
   _.keys = function(obj) {
     if(_.isArray(obj)) return _.range(0, obj.length);
     var keys = [];
-    for (var key in obj) if (oproto.hasOwnProperty.call(obj, key)) keys.push(key);
+    for (var key in obj) if (objPro.hasOwnProperty.call(obj, key)) keys.push(key);
     return keys;
   };
 
@@ -456,27 +456,27 @@
 
   // Is a given value a real Array?
   _.isArray = function(obj) {
-    return oproto.toString.call(obj) == '[object Array]';
+    return objPro.toString.call(obj) == '[object Array]';
   };
 
   // Is a given value a Function?
   _.isFunction = function(obj) {
-    return oproto.toString.call(obj) == '[object Function]';
+    return objPro.toString.call(obj) == '[object Function]';
   };
 
   // Is a given value a String?
   _.isString = function(obj) {
-    return oproto.toString.call(obj) == '[object String]';
+    return objPro.toString.call(obj) == '[object String]';
   };
 
   // Is a given value a Number?
   _.isNumber = function(obj) {
-    return oproto.toString.call(obj) == '[object Number]';
+    return objPro.toString.call(obj) == '[object Number]';
   };
 
   // Is a given value a Date?
   _.isDate = function(obj) {
-    return oproto.toString.call(obj) == '[object Date]';
+    return objPro.toString.call(obj) == '[object Date]';
   };
 
   // Is the given value NaN -- this one is interesting. NaN != NaN, and