Way back when in undergrad CS, I had been fascinated with functional programming. The teacher was reviled by everyone but me, because each lesson would put many more questions into your head than it did answer. I am not a very intelligent guy: I get by on sheer perseverance and putting in the work, and although I have good memory and a knack for explaining things, I get few good ideas. In the past five years, all good ideas I’ve got were about functional languages and programming, which might explain why I did not do so good as an imaging researcher (always dreaming about FP).

Anyway, this paper outlines clearly and concisely some of the best ideas of FP, high-order functions and lazy evaluation, and especially why they are such good ideas that software devs must take notice of them, have them lurk in their minds’ background. Learning some FP, using any language that can support at least some sort of lazy evaluation, is an experience I highly recommend.