Ever play charades? You need to make your audience understand the word in your head by acting it out. Well that’s what we’re going to do in a series of blog posts. Except the words I am thinking of don’t exist in English. Yeah, people give them pseudo-math names, but those are uninformative too.

It doesn’t help to name concepts with weird squiggles like “applicative functor”. If you look at old-fashioned math the names are always simple and are meant to suggest an analogy, because the primary function of math is to communicate precise intuition. So I’m going to find examples of <$> and <*> in action and see if we can spot the general pattern of how they work.

But I simply don’t have time to finish it tonight. I’ve spent my day after work struggling through this paper and looking for examples online. I have a few examples to work with now but not enough to for you (or me!) to solve the charades puzzle.

Want to help me out? Comment on this article with some of your favorite, idiomatic, useful examples using applicative functors acting on various types.