Implemented logical operator

lib/model.js

@@ -324,6 +324,8 @@ comparisonFunctions.$gte = function (a, b) {
 
 /**
  * Match any of the subqueries
+ * @param {Model} obj
+ * @param {Array of Queries} query
  */
 logicalOperators.$or = function (obj, query) {
   var i;
@@ -340,6 +342,8 @@ logicalOperators.$or = function (obj, query) {
 
 /**
  * Match all of the subqueries
+ * @param {Model} obj
+ * @param {Array of Queries} query
  */
 logicalOperators.$and = function (obj, query) {
   var i;
@@ -354,6 +358,16 @@ logicalOperators.$and = function (obj, query) {
 };
 
 
+/**
+ * Inverted match of the query
+ * @param {Model} obj
+ * @param {Query} query
+ */
+logicalOperators.$not = function (obj, query) {
+  return !match(obj, query);
+};
+
+
 /**
  * Tell if a given document matches a query
  * @param {Object} obj Document to check

test/model.test.js

@@ -482,7 +482,7 @@ describe('Model', function () {
     });
 
 
-    describe('Logical operators $or, $and', function () {
+    describe('Logical operators $or, $and, $not', function () {
 
       it('Any of the subqueries should match for an $or to match', function () {
         model.match({ hello: 'world' }, { $or: [ { hello: 'pluton' }, { hello: 'world' } ] }).should.equal(true);
@@ -499,6 +499,11 @@ describe('Model', function () {
         model.match({ hello: 'world', age: 15 }, { $and: [ { hello: 'pluton' }, { age: { $lt: 20 } } ] }).should.equal(false);
       });
 
+      it('Subquery should not match for a $not to match', function () {
+        model.match({ a: 5, b: 10 }, { a: 5 }).should.equal(true);
+        model.match({ a: 5, b: 10 }, { $not: { a: 5 } }).should.equal(false);
+      });
+
       it('Logical operators are all top-level, only other logical operators can be above', function () {
         (function () { model.match({ a: { b: 7 } }, { a: { $or: [ { b: 5 }, { b: 7 } ] } })}).should.throw();
         model.match({ a: { b: 7 } }, { $or: [ { "a.b": 5 }, { "a.b": 7 } ] }).should.equal(true);