gistfile1.coffee

placeholder = "What needs to be done?"

type Filter = All | Active | Complete

filterFn = case Filter of
  All: constant True
  Complete: (eq .complete)
  Active: (not << eq) .complete

App {
  state: { filter: All, newText: "", tasks: [] }

  action:
    add:
      @tasks = @tasks :: { done: False, editing: false, text: @newText }
      @newText = ""

    remove task:
      @tasks = filter (eq task) @tasks

    clearDone:
      @tasks = filter (eq .done) @tasks

  template:
    textbox(sync: @newText, enter: :add, placeholder: placeholder)
    button.activate-all(click: @tasks = map (.done = True) @tasks)
    .item(
      repeat<task>: filter (filterFn @filter) @tasks
      dblClick: .editing = True
      class<done>: .done
    )
      textbox(sync: .text, if: .editing)
     .text(if: not .editing) {.text}
     button.remove(click: :remove task) x
     button.done(click: .done = true) done

    button.clear-done(click: :clearDone)
    .items-left {length <| filter (not << eq <| .done) @tasks}

}