[telesphore]

I dunno, I agree that data flow is important and maybe the most important part of functional programming. But the ability to sling program fragments (partial application, pointless functions, etc.) around as if they were data seems pretty important to me. I think of it as Lego-blocks for programs. If the program parts snap together real easy and the data moves seamlessly (or seemlessly-ish) from end-to-end then you're on the right track.

But I suppose there are many paths to functional programming... I have only followed one so far.