deck.loop.js

$(document).on('deck.beforeChange', function(event, from, to) {
  var $slides = $.deck('getSlides');
  var onLastSlide = from === $slides.length - 1;
  var onFirstSlide = !from;
  var goingForward = to > from;
  
  if (onLastSlide && goingForward) {
    event.preventDefault();
    $.deck('go', 0);
  }
  else if (onFirstSlide && !goingForward) {
    event.preventDefault();
    $.deck('go', $slides.length - 1)
  }
});