proposal-private-fields VS proposal-type-annotations

> - # private... not sure why they didn't just use the "private" keyword, but I don't care. I almost always use TypeScript anyways

One of the reasons was to allow private and public fields of the same name, so that subclasses are free to add own public fields without accidentally discovering private fields. There were many more considerations that went into the design: https://github.com/tc39/proposal-class-fields/blob/main/PRIV....

There was a heated debate about this and the choice of the # sigil back in 2015 at the time private fields were being designed: https://github.com/tc39/proposal-private-fields/issues/14.

The inability to correctly polyfill this, which still keeping the variables private, was a subject of debate in TC39. One of the explicit advantages of moving to a "soft private" model (as discussed here: https://github.com/tc39/proposal-private-fields/issues/33) was that it could be polyfilled correctly.

There was a long and thoughtful article explaining why the private keyword was not enough; but now I can't find it :-( Here's the best replacement I could find: https://github.com/tc39/proposal-private-fields/issues/14 Effectively, what they are saying, is that you need to be able, within a class method, to disambiguate whether you are dealing with a private field of an identically named public field, and the keyword doesn't help with this.

This is all covered here:

https://github.com/tc39/proposal-private-fields/blob/master/...

As well, the Issues section of that proposal repo, as well as the Issues section of the original Private Fields repo (before it was merged with the Class Fields proposal) contain lots of discussion about this topic.

That proposal is not fully compatible with Typescript: https://github.com/tc39/proposal-type-annotations?tab=readme...

They held a meeting a few months ago so it's alive but probably still years away.

https://github.com/tc39/proposal-type-annotations/issues/184

I particularly like this thread in the TC39 types proposal. TypeScript IS a development trojan horse and locks you into the Microsoft Way of being a JS developer.

Edit: There is a proposal to extend JavaScript with type annotations, which would allow ("a reasonably large subset") of TypeScript to run directly in the browser. Yay!

https://github.com/tc39/proposal-type-annotations

More importantly, TypeScript typically commits to build things into itself when the proposal in JavaScript reaches Stage 3. The pattern matching proposal in JavaScript is Stage 1, but depends on many other proposals as well that may or may not need to be at Stage 3 as well for it to work. This particular proposal is interested on pattern matching on JavaScript Objects and other primitives, just like Python does with it’s native primitives. These are also dynamic types which helps in some areas, but makes it harder than others. Additionally, the JavaScript type annotations proposal needs to possibly account for this. So it’s going to be awhile. Like many years.

this is exactly what I want from the _Types as Comments_ proposal[0] as I think it's the only way that types can feasibly become part of the language. It's hard to imagine how all of the concepts TS introduces via special syntax can be covered otherwise.

[0] https://tc39.es/proposal-type-annotations

Crossing my fingers that the proposal for allowing (browser-ignored) type annotations in javascript progresses: https://tc39.es/proposal-type-annotations/

Between that, HTTP2/3 and ES modules many of the downsides for building apps with no compile step are almost completely mitigated.

JSDoc can get you pretty far, but it can be clumsy sometimes. There’s a [TC39 proposal](https://github.com/tc39/proposal-type-annotations) to allow types to live in JS code and be treated as comments (similar with Python types today)