vs.debounce.js

(function(window){
  window.vs = window.vs || {};
  window.vs.debounce = window.vs.debounce || debounce;

  // Snatched debounce function from underscore.js
  function debounce(func, wait, immediate) {
    var timeout;

    return function() {
      var context = this, args = arguments;
      var later = function() {
        timeout = null;
        if( !immediate ) {
          func.apply(context, args);
        }
      };
      var callNow = immediate && !timeout;
      clearTimeout(timeout);
      timeout = setTimeout(later, wait);

      if( callNow ) {
        func.apply(context, args);
      }
    };
  };
})(window, undefined);