compact and size for Hash (can't do .length since the function protot…

…ype has that)

lib/hash.js

@@ -113,6 +113,10 @@ function Hash (hash, xs) {
         return Object.keys(hash).length;
     } });
 
+    Object.defineProperty(self, 'size', { get : function () {
+        return self.length;
+    } });
+
     return self;
 };
 
@@ -183,3 +187,12 @@ Hash.concat = function (xs) {
 Hash.zip = function (xs, ys) {
     return Hash(xs, ys).items;
 };
+
+// .length is already defined for function prototypes
+Hash.size = function (ref) {
+    return Hash(ref).size;
+};
+
+Hash.compact = function (ref) {
+    return Hash(ref).compact.items;
+};

test/hash.js

@@ -47,6 +47,12 @@ exports['filter and values'] = function (assert) {
     assert.equal(Hash(ref).length, 4);
 };
 
+exports.length = function (assert) {
+    assert.equal(Hash({ a : 1, b : [2,3], c : 4 }).length, 3);
+    assert.equal(Hash({ a : 1, b : [2,3], c : 4 }).size, 3);
+    assert.equal(Hash.size({ a : 1, b : [2,3], c : 4 }), 3);
+};
+
 exports.concat = function (assert) {
     var ref1 = { a : 1, b : 2 };
     var ref2 = { foo : 100, bar : 200 };
@@ -122,6 +128,8 @@ exports.compact = function (assert) {
             f : null
         }
     );
+    var h = Hash.compact(hash);
+    assert.deepEqual(h, compacted.items);
 };
 
 exports.valuesAt = function (assert) {