Functional Programming Is Hard,That's Why It's Good

Odds are, you don’t use a functional programming language every day. You probably aren’t getting paid to write code in Scala, Haskell, Erlang, F#, or a Lisp Dialect. The vast majority of people in the industry use OO languages like Python, Ruby, Java or C#–and they’re happy with them. Sure, they might occasionally use a “functional feature” like “blocks” now and then, but they aren’t writing functional code.

And yet, for years we’ve been told that functional languages are awesome. I still remember how confused I was when I first read ESR’s famous essay about learning Lisp. Most people are probably more familiar with Paul Graham’s “Beating The Averages” which makes the case that:

But with Lisp our development cycle was so fast that we could sometimes duplicate a new feature within a day or two of a competitor announcing it in a press release. By the time journalists covering the press release got round to calling us, we would have the new feature too.

A common thread among people proselytizing functional programming is that learning this new, functional language is “good for you”; almost like someone prescribing 30m in the gym a day will “make you fit,” but it also implies difficulty and dedication. Haskell, Ocaml, and Scala are different from Lisp in that they have a certain notoriety for being very hard to learn. Polite people call this “being broad & deep”. Less polite people call it “mental masturbation” or “academic wankery” or just plain “unnecessary.” I submit that this difficulty is a familiar situation, and it’s a strong indicator that learning one of these languages will make you more productive and competent at writing software.

Your First Time Wasn’t Gentle