Hello, fn42

Welcome to fn42.dev — my little corner of the internet. The name is a tiny manifesto: fn for functional, the paradigm I enjoy the most, and 42 because, according to The Hitchhiker's Guide to the Galaxy, it is the answer to life, the universe, and everything.

This site is a hub: notes on programming, experiments, and ideas worth keeping.

Functions all the way down

I like code that reads like a description of what, not how. Pure functions compose, and composition scales:

type Fn<A, B> = (a: A) => B;
 
const compose =
  <A, B, C>(g: Fn<B, C>, f: Fn<A, B>): Fn<A, C> =>
  (a) =>
    g(f(a));
 
const hello = (s: string) => "Hello " + s;
const world = (s: string) => s + "world!";
 
const greeting = compose(world, hello)(""); // "Hello world!"

Don't panic. And always know where your towel is.