Binary walk function

gistfile1.js

/*
 * Home in on a number in binary search fashion.
 * binWalk(2048) === 1024
 * binWalk(2048, -1) === 512
 * binWalk(2048, -1, -1) === 256
 * binWalk(2048, -1, -1, -1) === 128
 * binWalk(2048, -1, 1) === 1536
 */

function binWalk(n){
  var lo = 0, hi = n, pointer = Math.floor(n/2)
  for (var i = 1; i<arguments.length; i++){
    var arg = arguments[i]
    if (arg > 0) {
      lo = pointer
    } else {
      hi = pointer
    }
    pointer = lo + Math.floor((hi - lo) / 2)
  }
  return pointer
}