monocle-ts VS proposal-record-tuple

Instead of the "deep path properties" syntax, you might want to take the opportunity to learn about functional lenses with monocle-ts

https://gcanti.github.io/monocle-ts/

You may be interested also in checking out the implementation of Lens in monocle-ts, one of the libraries in the fp-ts ecosystem

For anyone - anyone who's faffed around with JavaScript's spread syntax when working with nested immutable data, anyway - struggling to understand the general concept or utility of lenses, I'd encourage looking into monocle-ts. The motivation [0] that kicks off the README instantly made me a believer, and TypeScript's idiosyncratic type system makes using the library remarkably natural; it fits right in without needing to deal with anything analogous to Template Haskell.

[0] https://github.com/gcanti/monocle-ts#motivation

You could have a look at the monocle-ts library. It was designed to deal with this kind of problem.

spectacles-ts integrates seamlessly with the fp-ts ecosystem (it's built on top of the excellent monocle-ts library)

lenses help with this quite a bit, check out monocle-ts

You notice that Getters are composable as they are just pure functions, but the fact that setters are mutating values is not that nice. Tho, at this point we have invented quasi mutable lenses and If you really want you might invent actual purely functional lenses as well, but that’s for another day. Meanwhile you can take a look at an actual typescript lesses library from @gcanti / monocle-ts.

relevant issue, which is at the crux of this problem: https://github.com/tc39/proposal-record-tuple/issues/387

There are still so many basic things that aren't in the JS stdlib, though. A good example is Map - if you need to use a tuple of two values as a key, you're SOL because there's no way to customize key comparisons. Hopefully we'll get https://tc39.es/proposal-record-tuple/ eventually, but meanwhile languages ranging from C++ to Java to Python have had some sensible way to do this for over 20 years now.

If you’re reaching for structuredClone, what you really want is native immutable Record and Tuple syntax, and the companion “deep path properties” syntax which allows for efficient and ergonomic immutable updates:

- https://github.com/tc39/proposal-record-tuple

It will be called "record" in JavaScript which will swing the popularity back the other way I guess (currently a language proposal)

I suspect considering the strong desire to maintain consistency with JavaScript, we will eventually see something that when the Record proposal passes through tc39

I hope the Record and Tuple proposal makes it through

I mean, I'd love some real immutable/persistent data structures in JS by default, or even some Immer-like syntax sugar. Something like the record/tuple proposal would be awesome.

This will become very useful once Records and Tuples are a thing, because it allows you to store object references in a record/tuple (which by definition can only contain primitives).

Record and tuple is at stage 2

Also, js has an ongoing immutable value data types proposal.