Mixins in CoffeeScript (Example)

Somebody will send me straight to Hell for this madness, but it works! :)

Function::include = (mixin) ->
  for name, method of mixin
    method['super'] = @prototype[name]
    @prototype[name] = method

class Foo
  foo: -> 'foo from Foo'

Mixin =
  foo: ->
    "#{arguments.callee.super()}, foo from Mixin"

class Bar extends Foo
  @includee Mixin # yes, intended typo, otherwise coderwall messes it all up (coderwall team, please help me)

new Bar().foo() # => "foo from Foo, foo from Mixin"

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EDIT Renamed extend to include to avoid confusion for Rubists ;)