CoffeeScript chained lambdas for aop-based drawing

CoffeScript_Chained_Lambas.coffee

ctx = $('#canvas')[0].getContext("2d")
palette = {Gray:'#E8E8E8', Black:'#000000'}
point = (xVal, yVal) -> {x: xVal, y: yVal}	
line = (from, to) ->
	ctx.moveTo(from.x, from.y)
	ctx.lineTo(to.x, to.y)
	ctx.stroke()

class Chain
	constructor: -> 
		@chain = []
		this
	
	addLink: (func) => 
		@chain[@chain.length] = func
		this
		
	invoke: (func) => 
		i = 0
		invokeNext = () =>
			if i < @chain.length
				@chain[i++](() -> invokeNext()) 
			else 
				func()
		invokeNext()

class Path extends Chain
	constructor: ->	
                super
		this.addLink((inner) -> 
			ctx.beginPath()
			inner()
			ctx.closePath())

	withStroke: (color) =>
		this.addLink((inner) -> 
			old = ctx.strokeStyle
			ctx.strokeStyle = color
			inner()
			ctx.strokeStyle = old)
		
	draw: (func) => 
		this.invoke(func)
	
#######
# Fire off the Chain!
new Path().withStroke(palette.Gray).draw(() -> 
    line(point(0,0), point(100, 100))
)