$ coffee pubsub.coffee 
Just read big news today
Just read big news today
Just read big news today
About to fall asleep reading this interesting analysis

class Publisher
  constructor: ->
    @subscribers = { any:[] }

  subscribe: (fn, type) ->
    type = type or 'any'
    @subscribers[type] = [] unless @subscribers[type]?
    @subscribers[type].push(fn)

  unsubscribe: (fn, type) -> @visitSubscriers('unsubscribe', fn, type)

  publish: (publication, type) -> @visitSubscriers('publish', publication, type)

  visitSubscriers: (action, arg, type) ->
    pubtype = type or 'any'
    subscribers = @subscribers[pubtype]
    for subscribe,i in @subscribers[pubtype]
      switch action
        when 'publish' then subscribe(arg)
        else @subscribers[pubtype].splice(i,1) if subscribe is arg

  printSubscribers: -> console.log(@subscribers)

class Paper extends Publisher
  daily: => @publish('big news today')
  monthly: => @publish('interesting analysis','monthly')

class Subscriber
  drinkcoffee: (paper) -> console.log('Just read '+ paper)
  sundayPreNap: (paper) -> console.log('About to fall asleep reading this '+ paper)

paper = new Paper
joe = new Subscriber
paper.subscribe(joe.drinkcoffee)
paper.subscribe(joe.sundayPreNap, 'monthly')
#paper.printSubscribers()
paper.daily()
paper.daily()
paper.daily()
paper.monthly()