etude/client/templates/widget.esl

(lambda widget (closure)
  (var Widget (lambda (options)
    (if (! (instanceof this Widget)) (return (new Widget options)))
    (= this.options options)))
  (= Widget.prototype.type "Widget")
  (= Widget.prototype.init (lambda ()
    (= this.state (closure this.options))
    (return this.state.element)))
  (= Widget.prototype.update (lambda (prev)
    (= this.state prev.state)
    (return (?: this.state.update
      (this.state.update.apply this arguments) null))))
  (= Widget.prototype.destroy (lambda ()
    (if this.state.destroy (this.state.destroy.apply this arguments))))
  (return (lambda (options)
    (return (new Widget options)))))