Asynchronous if statements in CoffeeScript

gistfile1.coffee

class Async
    constructor: ->
        @stack = []
    
    @IF: (condition, fn) ->
        async = new Async
        async.stack.push (next) ->
            if condition then fn(next) else next()
        
        process.nextTick async.run.bind(async)
        return async
        
    ELSEIF: (condition, fn) ->
        @stack.push (next) ->
            if condition then fn(next) else next()
            
        return this
    
    ELSE: (fn) ->
        @stack.push fn
        return this
        
    run: ->
        stack = [@stack...]
        do next = ->
            fn = stack.shift()
            fn(next)
            
module.exports = Async

Usage.coffee

Async.IF somecondition, ->
    doSomething()
.ELSEIF someothercondition, ->
    doSomethingElse()
.ELSE ->
    anotherThing()