proposal-type-annotations VS closure-compiler

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)

Well, the nice thing with Python types is that the _only_ difference to untyped Python is the type annotations. Last time I worked with TypeScript (two and a half years ago), it felt more like a different language _similar_ to JS. In my experience it was quite... viral. With MyPy I've genuinely seen just specific parts of a code base become typed and didn't notice any friction.

I wonder what would happen if that proposal for type comments in JS went through. Would TypeScript become just a type checker / optimizing compiler?

Google's Closure had an (IMHO) nicer approach (https://github.com/google/closure-compiler/wiki/Types-in-the...), but I don't get the impression it'll ever catch on outside Google.

The most well-known tools that rely on JSDoc are Closure Compiler (not to be confused with the Closure programming language) and TypeScript. Both of these tools can help make your JavaScript typed, but they approach it differently. Closure Compiler primarily focuses on enhancing your .js files by adding typing through JSDoc annotations (after all, they are just comments), while TypeScript is designed for .ts files, introducing its own well-known TypeScript constructs such as type, interface, enum, namespace, and so on.

Closure Compiler follows the same line of thinking:

https://github.com/google/closure-compiler/wiki/FAQ#closure-...

I think only Google Closure Compiler did some optimizations based on its JSDoc-style annotations (see docs). If I remember correctly, types mostly allowed renaming objects' properties across modules, but most other advanced optimizations (like dead code elimination or functions inlining) didn't rely on types. In my experience properties renaming resulted in subtle, hard to discover bugs and I'd say they didn't bring much benefit.

The @template tag is supported by Google Closure Compiler

i'm not sure you want them to write back https://github.com/google/closure-compiler/pull/3958

time to fork