proposal-record-tuple VS immutable-js

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.

immutable for JavaScript.

Check out Object.freeze. There's also Immutable.js for working with immutable data.

Use immutability to manage state updates When updating state in your React application, it's important to ensure that you are not mutating the original state object. Instead, you should create a new copy of the state object with the updated values. Immutability makes it easier to manage state updates and ensures that the updates are performed in a predictable and safe manner. Libraries like Immutable.js provide a set of functions that simplify working with immutable data in React applications.

We're wanting to get rid of immutable so I'm trying to replicate what it is about the Record functionality and types that allow this dynamic property access to work. After pulling my hair out looking through the [email protected] type definitions and the actual code, to me it looks like the types are just kind of lying about what's going on ... and it's just working. Does anyone have any ideas how I can replicate this dynamic property access with strong typings?

The Immutable.js README has a much more complete description of immutability and why you might want to use the library. Also worth mentioning that Immer is an alternative which is a bit easier to get started with.

Examples: immutable-js Immer

I can't speak to C# and Java, but the suggestion in this post: ImmutableJS already uses Persistent data structures. (It's the second sentence of their introduction)

Avoiding mutation is just never modifiyng an object, ever. There are tons of implementations of this pattern, notably immutable.js (https://immutable-js.com/), Redux is also an example of this philosophy.

JavaScript is most programers' first introduction to map, filter, and reduce. Easy lambdas made those higher-order functions a staple of a lot of JS code.

Meanwhile, immutable.js[0] is at 10 million downloads per week and rising.

I would add that it's not just the ease of use of lambdas, but the fact that in JavaScript functions really are first class citizens. Most of the other widely used languages that people start on have lambda functions added in as a bit of a hack and only treat some functions as real values.

[0] https://www.npmjs.com/package/immutable