fixed group_by and added length operator

Author: kevinchekovfeeney

lib/woql.js

@@ -64,6 +64,7 @@ WOQL.divide = function(...args){ return new WOQLQuery().divide(...args); }
 WOQL.exp = function(a, b){	return new WOQLQuery().exp(a, b); }
 WOQL.div = function(...args){	return new WOQLQuery().div(...args); }
 WOQL.comment = function(arg){	return new WOQLQuery().comment(arg); }
+WOQL.length = function(var1, res){	return new WOQLQuery().length(var1, res);}	
 
 
 //language extensions that can be chained after 'grounded' stuff (clauses with a specific subject) sub, isa, delete_triple, add_triple, delete_quad, add_quad, node
@@ -160,6 +161,11 @@ WOQLQuery.prototype.typecast = function(va, type, vb){
 	return this;
 }
 
+WOQLQuery.prototype.length = function(va, vb){
+	this.cursor['length'] = [va, vb];
+	return this;
+}
+
 
 WOQLQuery.prototype.remote = function(json){
 	this.cursor['remote'] = [json];
@@ -190,7 +196,7 @@ WOQLQuery.prototype.group_by = function(gvarlist, groupedvar, groupquery, output
 		for(var i = 0; i<groupedvar.length; i++){
 			ng.push(groupedvar[i].substring(0, 2) != "v:" ? "v:" + groupedvar[i] : groupedvar);			
 		}
-		groupedvar = ng;
+		groupedvar = {"list": ng};
 	}
 	else if(typeof groupedvar == "string"){
 		if(groupedvar.substring(0, 2) != "v:") groupedvar = "v:" + groupedvar;