Why Isn't Functional Programming the Norm? [video]

JavaScript isn't a functional language itself, but you can use a functional library like lodash/fp (https://github.com/lodash/lodash/wiki/FP-Guide) on top of it to get all that lovely functional goodness in your frontend and node code. Using lodash/fp has made my frontend state management code a lot nicer, and I'm really only just starting out with it.

Personally, I think JS is a fine functional language. Like you say, it doesn't have a good FP style system library, but it doesn't have a good anything style system library ;-) My main complaint is that currying is awkward. One thing I have discovered, though, is that closures are relatively slow (that is, unoptimised) in most implementations. In several implementations, they can also leak memory in certain circumstances. There is a very old outstanding bug in V8 that gives a lot of details about this... unfortunately I'm not in a position at the moment to go spelunking for it (I wish I'd saved a link...)

Anyway, I've done quite a few fairly large katas in JS using only an FP style of coding without any dependencies and I really enjoyed it.

Personally I find functional style awkward in js. Mostly because data is not immutable, there are no functional operators (composition, application etc.) and no algebraic data types + pattern matching.

But most importantly, prototypal inheritance, in other words invoking the object's own methods as if they were pure functions is what really puts me off.