#acts-as

a simple class-level mixin module for Node.JS, which provides a handy "composition over inheritance" for writting complex programs

How To Use

require "acts_as"

class A

  this.toString = ->
    'ClassA'

  # after mixed in, use this method to detect who behaves like who (duck typing)
  this.isA = (obj) ->
    return if obj? then Boolean(obj["__is#{@}"]) else false

  a: ->
    console.log "[A.a] called"
    "AAA"

class B
  b: ->
    console.log "[B.b] called"
    "BBB"

class C
  @acts_as A,B
  c: ->
    console.log "[C.c] called"
    "CCC"

i = new C
console.dir i
console.log "i.a():#{i.a()}"
console.log "i.b():#{i.b()}"
console.log "i.c():#{i.c()}"
console.log "i behave like A? : #{A.isA(i)}"

Reference

This little module is inspired by:

1. discussion on coffee-script mixin: https://github.com/jashkenas/coffee-script/issues/452#issuecomment-3699651

2. acts_as in the Ruby's way: http://yehudakatz.com/2009/11/12/better-ruby-idioms/