gistfile1.js

macro forThing {
  case $val ($a:expr, $b:expr) => {(function($val){forEach.call($b, this)}).bind($a)}
	case $val ($a:expr) =>          {(function($val){forEach.call(val,this)}).bind($a)}
}
function makeMutationObserver(tag){
	var queue= tag.queue, 
	  put= queue.put.bind(queue),
	  mutationAddObserve= forThing val (put, val.getElementsByTagName(this.tag)),
	  mutationObserver= forThing val (mutationAddObserve, val.addedNodes),
	  mutationsObserver= forThing val (mutationObserver)
	return new MutationObserver(mutationsObserver)
}