Pattern matching (and expression based assignment, of which idk if there’s a proposal for or not) are two things that would really drive a ton of value.

It's going to end up looking a lot like C# [0][1]; these two/three (JS/TS, C#) languages have been converging for a while now. Now just waiting for C# to get official first party discriminated unions!

[0] https://learn.microsoft.com/en-us/dotnet/csharp/language-ref...

[1] https://timdeschryver.dev/blog/pattern-matching-examples-in-...

Just an FYI for those unaware TS & C# are both creations of Anders Hejlsberg & his colleagues at Microsoft. Both are some of my favorite languages as well.

We would all benefit if JS was more like C# in my opinion.

Assignment is already an expression, no?

    console.log(x = "hello");

Now try it with a constant:

    console.log(const x = "hello");

Doesn't work.

That's a declaration. That would be cool. Doesn't currently work with let or var either.

I think this is basically assigning values to the window object, similar to updating values in any object.

e.g.

    const a = { b: 1 }
    console.log(a.b = 2); // logs 2

Only if you haven't already declared the variable. e.g.

    let x;
    console.log(x = 'hello');

My point is that the `x = 'hello'` part is an assignment, and an expression, and has the exact same semantics regardless of whether you use that expression as a statement. So, assignments would seem to be expressions.

I also REALLY want records and tuples.

Unfortunately that proposal seems to be kinda dead.

React is a fundamentally flawed framework because of the lack of this feature. It inverts the responsibility of any non-primitive prop by putting the burden on the parent element instead of the child to decide when to rerender things. So elements are no longer self-contained if they receive any non-primitive values (besides react elements).

The React compiler auto-memoization that facebook is pushing also addresses this issue through build-time magic. I not fond of this approach.