Similar attempts include Scalajs.
The general challenge becomes integrating the fractional front-end code written in your backend-language that compiles to JS with the rest of the JS ecosystem.
JaneStreet have a love of writing their own stuff from scratch so it doesn't apply to them but it might to you.
Hence most people end up with frontend-as-backend rather than backend-as-frontend.
KotlinJs and ClojureJs too. You always end up having to write wrappers or dealing with problems that would just work if you just used normal js/ts.
Clojurescript not ClojureJs, and Typescript doesn't run in the browser, it has the exact same issues/limitations: it must be compiled to JavaScript first.
Except TS has much wider community support. The type definitions/wrappers are already written.
Compiling TypeScript is just stripping out types
Isn't that like saying the Internet is only written in English if you strip out all the non-English. All C-style languages are fully cross compatible if you only use semicolons.
I can't write Typescript into a browser without cross-compilation and "stripping out types" involves parsing and manipulating code. That's a different language.
That is true only if you confine your TS code to be pure JS plus type annotations.
There are TS constructs that require compilation into equivalent JS, such as enums and namespaces.
Are there any other?
Namespaces are heavily discouraged. Some teams still use enigma but most people in the know us unions of strings.
I know the TS team regrets enums and I have not seen any plans for adding additional keywords that break type stripping.
The other one I read about was parameter properties in constructors.
And thank you for the correction! It was quite a few years ago that I used TypeScript, and I think the landscape was different then.
Making things even fuzzier in my mind, this was an Angular project, and it was hard to keep track of what was Angular and what was TypeScript.
It sounds like people these days actively avoid the parts of TypeScript that require translation into different JS code.
"fortunately" we can load swc compiled to wasm to deal with that.
absolutely nobody used those outside of a language demo. We also got --erasableSyntaxOnly last year to remove them from the language. The TS team considers them “mistakes“ for a really long time now
Thanks for the correction! It was a long time ago that I used TypeScript, and making things worse (for my memory) it was an Angular project.
So today, most people and teams avoid the parts of TS that require compilation into different JS, and --erasableSyntaxOnly lets you enforce this, right?
Exactly. There is plenty of code change however introduced by bundlers who do “bundling“, polyfill injection, minification, this kind of stuff.
Yup, and Clojure/ClojureScript!
Couldn't WASM solve that problem once and for all? Is there some limitation that WASM has that JS doesn't?
Disclaimer: I am very inexperienced at front-end development.
> Is there some limitation that WASM has that JS doesn't?
You need a JS trampoline to call your WASM and make browser primitives available to it, and IIRC calls into browser code incur some extra overhead, but those are pretty manageable.
Additionally: for high level languages, source code is _much_ smaller than compiled binaries. If your initial needs are simple, your users are likely downloading more than 10x as much code.
WASM does not (yet) have access to the DOM or web APIs, meaning every direct interaction with the browser must first go through JS interop anyways, with a resulting performance penalty. There are proposals, and maybe we'll see it happen by 2035, but as of now WASM is best suited for heavier workloads where the edge in application performance outweighs the cost of JS interop with the browser rather than being a universal solution.
Such attempts are quite common. Some I remember:
https://ocsigen.org/ in Ocaml too
https://websharper.com/ for fsharp and csharp. Really good when I used in in fsharp
Maybe https://melange.re/v7.0.1/ too? (Not sure)
I took this as a joke in reference to the popularity of JavaScript on the backend for the last two decades.
that's because most people's intro to CS was how to build a webpage.
Modern web development is more like computer alchemy