proposal-change-array-by-copy VS proposal-iterator-helpers

The new change array by copy methods (ES2023) will also work with tuples. So while you can't

Change Array by Copy

Stage 3 Change array by copy proposal offers methods like sortTo() that return a new array instead of mutating the original.

Note: there's a stage 3 proposal that introduces copy = arr.toSorted().

Change Array by Copy: Provides additional methods on Array.prototype and TypedArray.prototype to enable changes on the array by returning a new copy of it with the change.

The proposal is described here, with the other methods being:

Proposal, Polyfill

You're unlikely to see any new methods being added to JavaScript's Array that would modify an array in place like reverse() and sort() do. In fact some of the new methods that are being added are versions of reverse() and sort() (and splice()) that create copies rather than modifying the originals. Read more about them here: Proposal: Change Array by copy.

Since cloning is so common, a new specification has been written which has reached stage 3, which will give us a host of new ways to copy and then change an array. This proposal is called the "Change Array by Copy" proposal. Let's take a look at how it works.

Global iterator type is coming: https://github.com/tc39/proposal-iterator-helpers

But a method named `groupBy` on iterators traditionally means a different thing: https://github.com/tc39/proposal-array-grouping/issues/51#is...

Global iterable type it's too late for, since there's many extant iterables in the language and on the web which don't have it in their prototype chain and can't reasonably be changed.

Very much agreed. The amount of mileage we get from using Spread (literally the ...) alone has been amazing. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe... Iteration helpers is shipping soon, that'll be a huge help (async iteration helpers will be delayed for a while). https://github.com/tc39/proposal-iterator-helpers .

In the olden days, I feel like the codebases I worked on needed to use .apply() multiple times a week, to figure out some creative way of invoking functions. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe... That's all gone now; I'd take even odds that 50% of my team knows .call and .apply.

Chrome 117 is shipping Object.groupBy() and that's gonna be a huge help in eliminating a lot of the last places we end up using lodash. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

Once this https://github.com/tc39/proposal-iterator-helpers reaches browsers, I'm prob gonna be exclusively using Maps.

No, probably not. But with iterator helpers, you can do

> focus more on improving the terrible JS web API

That's W3C’s job, not ECMA’s.

> Where are all the containers?

?

> Sorted sets/maps?

Sets and Maps are sorted (by insertion order)

> Why can't I even map an iterator?

It's coming, but someone will likely be exhausted by that addition. https://github.com/tc39/proposal-iterator-helpers

Upcoming: https://github.com/tc39/proposal-iterator-helpers

Not Generators, but Iterators have a Stage 3 proposal with helpers like these.

I guess you are not the only one dealing with this. That’s why there is this proposal https://github.com/tc39/proposal-iterator-helpers So hopefully it will get easier soon. But in most cases you can simply wrap it in Array.from or you can also clone with the spread operator.

Let's assume Number.range(), iterator helpers and some isPrime() function. From that we could easily create the following: