eval(readFile("Worlds_Compiled"))

array.push = function(x) {
  this[this.length] = x
  this.length = this.length + 1
}
array.pop = function() {
  var r = this[this.length - 1]
  this[this.length - 1] = null
  this.length = this.length - 1
  return r
}
array.last = function() {
  return this[this.length - 1]
}
worldProto.sprout = function() { return this.call(function() { return new world }) }


// --------------------------------------------------------------------


seaside = {
  worlds: [world],
  perform: function(action) {
    var w = this.worlds.last().sprout()
    this.worlds.push(w)
    return w.call(this[action])
  },
  back: function() {
    if (this.worlds.length > 0)
      this.worlds.pop()
  },
  flattenHistory: function() {
    while (this.worlds.length >= 2) {
      var w = this.worlds.pop()
      w.commit()
    }
  }
}

counter = function() {
  var count   = 0
  var me      = new seaside()
  me.inc      = function() { return count = count + 1 }
  return me
}()

x = "foo"
counter.perform("inc")
counter.perform("inc")
counter.perform("inc")
x = "bar"
counter.back()
counter.perform("inc")
x