Coffeescript Mixins

example.coffee

Mixin = require './mixin.coffee'
Module = require './module.coffee'

class Logger extends Mixin
  yo = (msg) -> console.log msg
  class_log: yo
  @log: yo

class MyLogger extends Module
  @extends Logger
class MyOtherLogger extends Module
  @extends Logger


test = new MyLogger
test.log 'yo'
MyAlerter.class_log 'class yo'

x.class_alert 'neat-o' for x in Alerter::extensions

mixin.coffee

class Mixin
  extensions: []
  extended: (obj) -> @extensions.push obj

module.exports = Mixin

module.coffee

MIXIN_KEYWORDS = ['extended', 'extensions']

IGNORED_KEYS = ['constructor', '__super__'].concat MIXIN_KEYWORDS

class Module
  # Private Methods
  materialize = (obj) ->
    if obj instanceof Function then new obj() else obj
  extend = (target, obj) ->
    for key, value of obj when key not in IGNORED_KEYS
      target::[key] = value
    for key, value of (obj::) when key not in IGNORED_KEYS
      target[key] = value

  # Class Methods
  @extends: (obj) ->
    extend @, obj
    materialize(obj).extended?(@)
    this

module.exports = Module