Debounce in CoffeeScript

debounce.coffee

# Debounce and SmartResize (in jQuery) ported to CoffeeScript
# debouncing function from John Hann
# http://unscriptable.com/index.php/2009/03/20/debouncing-javascript-methods/

  debounce = (func, threshold, execAsap) ->
    timeout = false
    
    return debounced = ->
      obj = this
      args = arguments
      
      delayed = ->
        func.apply(obj, args) unless execAsap
        timeout = null
      
      if timeout
        clearTimeout(timeout)
      else if (execAsap)
        func.apply(obj, args)
      
      timeout = setTimeout delayed, threshold || 100
  
  # Smartresize
  jQuery.fn['smartresize'] = (fn) ->
    if fn then this.bind('resize', debounce(fn)) else this.trigger('smartresize')