Abstracting touch and pointer events with an iterator function

eachTouchEvent.js

    
   function onTouchStart( event ){
        eachTouchEvent( event, function( i, ev ){
              ev.clientX; // <- do something with this
        } );
        return true;
    }    


    function eachTouchEvent( event, callback ){
        // microsoft's pointer events aren't multi
        if( navigator.msPointerEnabled ){
            if( event.MSPOINTER_TYPE_TOUCH === event.pointerType ){
                callback( 0, event );
            }
            // else not a touch interaction
            return;
        }
        // regular multi-touch support
        var i = -1, 
            touched = event.originalEvent || event,
            changed = touched.changedTouches||[];
        while( ++i < changed.length ){
            callback( i, changed[i] );
        }    
    }


element.addEventListener(  navigator.msPointerEnabled ? 'MSPointerDown' : 'touchstart', onTouchStart, false );