[codedokode]

FP principle is that functions are first-class objects and one can pass a function to a function. I don't see how it helps programming the UI. Maybe you meant using immutable data structures? I mentioned that and noted that they have their own issues and generally are a pain to use.

> If your whole tree is recalculating on every mousemove event

If you update a variable in the root component, that will happen. Am I wrong?

[schwartzworld]

Thats the 1-sentence summary of FP, but there’s a lot more to it. Immutable data structures are part of it, although less important because of how props are scoped.

Composition, my friend. That’s the key. If your whole tree is rerendering whenever your state changes, it’s a failure to compose your components properly.

FP includes strategies for limiting side effects, relying on architectural patterns that push side effects to the edges of your application. This is a very sane way of working in react.

And a lot of prop drilling can be reduced by passing down closure functions with curried values in them.