variant VS proposal-type-annotations

Variant

When working in a TS codebase I'll lean on this variant library, which works pretty well as far as simple sum types go (v3 is great but not stable yet).

About half-way through writing this library I discovered that Variant existed... and does a great job at doing the exact same things (and more). I might not have started if I knew about that, but I'm glad I did because it has been a great learning experience!

Oddly enough, this feature alone has been a a big draw to Rust, Haskell and functional programming in general for me... so it's nice that there's libs filling the gap for TypeScript. Here's another one I haven't gotten around to trying yet either.

I had to solve this for a project of mine.

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)