Quickly and recursively traverse DOM elements.

traverse_dom.js

function traverseDom(elm, visit){
  visit(elm)
  var curr = elm.firstChild
  while (curr){
    if (curr.nodeType === 1){
      traverseDom(curr, visit)
    }
    curr = curr.nextSibling
  }
}

var count = 0
var start = + new Date
traverseDom(document.documentElement, function(elm){
  count++
})
var end = + new Date
console.log('Took ' + (end - start) + 'ms')
console.log('Total # of elements = ' + count)