New operator and extended dot operator document search

lib/model.js

@@ -12,6 +12,7 @@ var dateToJSON = function () { return { $$date: this.getTime() }; }
   , lastStepModifierFunctions = {}
   , comparisonFunctions = {}
   , logicalOperators = {}
+  , queryOperators = {}
   ;
 
 
@@ -439,6 +440,12 @@ function getDotValue (obj, field) {
 
   if (fieldParts.length === 1) {
     return obj[fieldParts[0]];
+  } else if (util.isArray(obj[fieldParts[0]])) {
+      var objs = new Array();
+      for (var i = 0; i < obj[fieldParts[0]].length; i += 1) {
+         objs = objs.concat(getDotValue(obj[fieldParts[0]][i], fieldParts.slice(1).join('.')));
+      }
+      return objs;
   } else {
     return getDotValue(obj[fieldParts[0]], fieldParts.slice(1));
   }
@@ -566,7 +573,6 @@ comparisonFunctions.$exists = function (value, exists) {
   }
 };
 
-
 /**
  * Match any of the subqueries
  * @param {Model} obj
@@ -613,6 +619,17 @@ logicalOperators.$not = function (obj, query) {
 };
 
 
+/**
+ *
+ * @param obj
+ * @param value
+ * @returns {*|boolean}
+ */
+queryOperators.$size = function (obj, value) {
+    return (util.isArray(obj) && obj.length == value);
+};
+
+
 /**
  * Tell if a given document matches a query 
  * @param {Object} obj Document to check
@@ -653,21 +670,29 @@ function matchQueryPart (obj, queryKey, queryValue) {
     var objValue = getDotValue(obj, queryKey)
         , i, keys, firstChars, dollarFirstChars;
 
+    keys = Object.keys(queryValue);
+    firstChars = _.map(keys, function (item) { return item[0]; });
+    dollarFirstChars = _.filter(firstChars, function (c) { return c === '$'; });
+
     // Check if the object value is an array treat it as an array of { obj, query }
     // Where there needs to be at least one match
     if (util.isArray(objValue)) {
+        if (dollarFirstChars.length > 0) {
+            if (!queryOperators[keys[0]]) { throw "Unknown query operator " + keys[i]; }
+
+            if (!queryOperators[keys[0]](objValue, queryValue[keys[0]])) { return false; }
+            return true;
+        } else {
             for (i = 0; i < objValue.length; i += 1) {
                 if (matchQueryPart({ k: objValue[i] }, 'k', queryValue)) { return true; }   // k here could be any string
             }
             return false;
         }
+    }
 
     // queryValue is an actual object. Determine whether it contains comparison operators
     // or only normal fields. Mixed objects are not allowed
     if (queryValue !== null && typeof queryValue === 'object' && !util.isRegExp(queryValue)) {
-    keys = Object.keys(queryValue);
-    firstChars = _.map(keys, function (item) { return item[0]; });
-    dollarFirstChars = _.filter(firstChars, function (c) { return c === '$'; });
 
         if (dollarFirstChars.length !== 0 && dollarFirstChars.length !== firstChars.length) {
             throw "You cannot mix operators and normal fields";