This is a simple function that has been created to help support responsive development where often both mouse and touch events are needed to be supported & code to actually create handlers for both types of events get a bit over complicated.
Simply include the function into your source and bind the required touch events to their counterpart mouse events.
document.addEventListener('touchstart',function(e){ mapTouchEvents(e,'mousedown'); },true);
document.addEventListener('touchmove',function(e){ mapTouchEvents(e,'mousemove'); },true);
document.addEventListener('touchend',function(e){ mapTouchEvents(e,'mouseup'); },true);
document.addEventListener('touchcancel',function(e){ mapTouchEvents(e,'mouseup'); },true);
Above snippet shows how to map the touch events to mouse events. Please make sure your bind the events as exactly shown above having the function(e){mapTouchEvents(e,'mousedown');} where mousedown is the mouse event being mapped to touchstart event.
Now if you have defined an event handler for mousedown it would also be called when touchstart happens.