Nothing of value is 100% "pure", eventually you are gonna need to draw something to the screen, so trying to reach that sort of utopia seems futile.
With that said, the "mental model" of React, or maybe the focus, is "pure" where it matters, namely that you have data, pass it through a function, and you get a view/UI, and if you pass the same data, you get the same UI, regardless of what happened before.
When it appeared, was very different from us web developers were used to, where sometimes the DOM even was our data store, and mutation was the name of the game.
So when people say "React is pure", I don't think they're talking about internally, or "100% pure", just that the mental model you need to adjust to is that the UI gets created from (mostly) pure functions.
Of course, this all breaks down once the frontend application actually runs in a browser, but that doesn't mean it isn't valuable for the developer as things gets a lot simpler.
Not disagreeing with you in the end I guess, just clarifying for those who might not be familiar with React, and get confused when some people say it's pure, while others don't. Both are right :)
Nope, that is precisely what pure functional programming is about: to turn actions like "draw something to the screen" into regular values that you can store into a variable, pass around, return from a function and so on.
It's not an utopia. It will eventually happen and it will replace how react.js currently works. effect.website will probably be the foundation.
I'm well aware of what "pure functional programming" is about, I spend most of my time in Clojure during a normal work day, and done my fair deal of Haskell too :)
And yes, even the most pure functional language eventually needs to do something non-pure, even if the entire flow up until that point is pure, that last step (IO) just cannot be pure, no matter how badly you want it to.
With that said, you'd have to pry my pure functions out of my cold dead hands, but I'm not living under the illusion that every function can be pure in a typical application, unless you have no outputs at all.
With that said, the "mental model" of React, or maybe the focus, is "pure" where it matters, namely that you have data, pass it through a function, and you get a view/UI, and if you pass the same data, you get the same UI, regardless of what happened before.
When it appeared, was very different from us web developers were used to, where sometimes the DOM even was our data store, and mutation was the name of the game.
So when people say "React is pure", I don't think they're talking about internally, or "100% pure", just that the mental model you need to adjust to is that the UI gets created from (mostly) pure functions.
Of course, this all breaks down once the frontend application actually runs in a browser, but that doesn't mean it isn't valuable for the developer as things gets a lot simpler.
Not disagreeing with you in the end I guess, just clarifying for those who might not be familiar with React, and get confused when some people say it's pure, while others don't. Both are right :)