Functional equivalent of decorator pattern?

Question

What is the functional programming equivalent of the decorator design pattern?

For example, how would you write this particular example in a functional style?

Answer 1

I'm not 100% sure but I think the C9 lecture series on advanced functional programming explains the problem really good.

Aside from this you can use just the same technique inside F# (it supports just the same OO mechanism) and in this special case I would do so.

I guess it's a matter of tast and the problem you are trying to solve.