bit of code (part of a larger object not shown) that handles batching of a huge CORS POST into several JSONP requests. The rwJSONP function returns a promise

batching a CORS request as a backup

          batchIt: function(q){
            var b = $.Deferred(), 
              batches = [],
              per=3,
              nq,
              nids=[];
           
            $.each(q.ids,function(i,v){
              nids.push(v);
              if (nids.length===per) {
                nq = $.extend({}, q);
                nq.ids = nids;
                batches.push(hashC.rwJSONP(nq));
                nids = [];
              }
            });
            
            $.when.apply(this,batches).then(function(){
              //need to merge all the arguments back together into a single result, oy
              var result ={};
              $.each(arguments,function(i,v){
                $.extend(result,v[0]);               
              });
              b.resolve(result);
            },function(){
              //one of the batches failed.  darn
              b.reject();
            });
            return b.promise();
          }