SVG.Set = SVG.invent({
  // Initialize
  create: function(members) {
    if (members instanceof SVG.Set) {
      this.members = members.members.slice()
    } else {
      Array.isArray(members) ? this.members = members : this.clear()
    }
  }

  // Add class methods
, extend: {
    // Add element to set
    add: function() {
      var i, il, elements = [].slice.call(arguments)

      for (i = 0, il = elements.length; i < il; i++)
        this.members.push(elements[i])

      return this
    }
    // Remove element from set
  , remove: function(element) {
      var i = this.index(element)

      // remove given child
      if (i > -1)
        this.members.splice(i, 1)

      return this
    }
    // Iterate over all members
  , each: function(block) {
      for (var i = 0, il = this.members.length; i < il; i++)
        block.apply(this.members[i], [i, this.members])

      return this
    }
    // Restore to defaults
  , clear: function() {
      // initialize store
      this.members = []

      return this
    }
    // Get the length of a set
  , length: function() {
      return this.members.length
    }
    // Checks if a given element is present in set
  , has: function(element) {
      return this.index(element) >= 0
    }
    // retuns index of given element in set
  , index: function(element) {
      return this.members.indexOf(element)
    }
    // Get member at given index
  , get: function(i) {
      return this.members[i]
    }
    // Get first member
  , first: function() {
      return this.get(0)
    }
    // Get last member
  , last: function() {
      return this.get(this.members.length - 1)
    }
    // Default value
  , valueOf: function() {
      return this.members
    }
    // Get the bounding box of all members included or empty box if set has no items
  , bbox: function(){
      // return an empty box of there are no members
      if (this.members.length == 0)
        return new SVG.RBox()

      // get the first rbox and update the target bbox
      var rbox = this.members[0].rbox(this.members[0].doc())

      this.each(function() {
        // user rbox for correct position and visual representation
        rbox = rbox.merge(this.rbox(this.doc()))
      })

      return rbox
    }
  }

  // Add parent method
, construct: {
    // Create a new set
    set: function(members) {
      return new SVG.Set(members)
    }
  }
})

SVG.FX.Set = SVG.invent({
  // Initialize node
  create: function(set) {
    // store reference to set
    this.set = set
  }

})

// Alias methods
SVG.Set.inherit = function() {
  var m
    , methods = []

  // gather shape methods
  for(var m in SVG.Shape.prototype)
    if (typeof SVG.Shape.prototype[m] == 'function' && typeof SVG.Set.prototype[m] != 'function')
      methods.push(m)

  // apply shape aliasses
  methods.forEach(function(method) {
    SVG.Set.prototype[method] = function() {
      for (var i = 0, il = this.members.length; i < il; i++)
        if (this.members[i] && typeof this.members[i][method] == 'function')
          this.members[i][method].apply(this.members[i], arguments)

      return method == 'animate' ? (this.fx || (this.fx = new SVG.FX.Set(this))) : this
    }
  })

  // clear methods for the next round
  methods = []

  // gather fx methods
  for(var m in SVG.FX.prototype)
    if (typeof SVG.FX.prototype[m] == 'function' && typeof SVG.FX.Set.prototype[m] != 'function')
      methods.push(m)

  // apply fx aliasses
  methods.forEach(function(method) {
    SVG.FX.Set.prototype[method] = function() {
      for (var i = 0, il = this.set.members.length; i < il; i++)
        this.set.members[i].fx[method].apply(this.set.members[i].fx, arguments)

      return this
    }
  })
}
