function Ansync (totalCount, segmentCount, workCallback, returnCallback) {     var num_of_item_for_each_segment = segmentCount;     var num_of_segment = Math.ceil(totalCount / num_of_item_for_each_segment);     var count_of_segment = 0;     var timer;     var start, end;     this.process = function(scope, timeout)     {         if (scope != undefined)         {             workCallback = workCallback.bind(scope);             returnCallback = returnCallback ? returnCallback.bind(scope) : undefined;         }         if (count_of_segment == num_of_segment)         {             clearTimeout(timer);             if (returnCallback != undefined)                 returnCallback();         }         else         {             start = count_of_segment * num_of_item_for_each_segment;             end = Math.min(totalCount, (count_of_segment + 1) * num_of_item_for_each_segment);             if (num_of_segment == 1)//needn't create timer             {                 workCallback(start, end);                 count_of_segment = 1;                 this.process();             }             else             {                 timer = setTimeout(function ansyncTimeout(){                     if (workCallback(start, end)) //finish process if function returns true                     {                         count_of_segment = num_of_segment;                     }                     else                     {                         count_of_segment++;                     }                     this.scope.process();                 }.bind({scope: this}),timeout == undefined ? Ansync.TimeOut : timeout);             }         }     } } Ansync.TimeOut = 5;