GHC now runs in the browser

https://discourse.haskell.org/t/what-s-needed-to-bootstrap-g... people have worked replaying the history to bootstrap.

How is ghc compiled at all without bootstrapping? Or is there a magic binary in tree that is unreproducible? I have compiled ghc a few times and had no problems.

GHC (the Glasgow Haskell Compiler, after its original host university) is de facto the Haskell compiler and simultaneously the main research vehicle for the language and the neighbouring design space in general.

And frankly, while the compiler is awesome and so is the research, the constant churn and seeming inability to settle on what the good programming style and set of features actually is is what eventually turned me away from the language and to the more stable (if near-abandoned) pastures of Standard ML. (That was during the type families upheaval, so, about ten years ago? Don’t know how well it reflects the current state of the project.)

I think WasmGC is very hard to make work with laziness. A lazy value is always a closure on the heap.

If an expression might be unused, throw a closure which computes it on the heap

If the value is actually needed, invoke the closure. Optionally replace the closure with a black hole. A black hole is just a closure which pauses any thread which calls it, to be resumed once the first thread finishes with the expression

Once finished, replace with a closure which immediately returns the computation result. (Or often save the indirection because most concrete values also act as closures which immediately returns themselves using info table pointers trickery)

Anyway, iirc WasmGC wants very rigid types without dynamic type changes. Extra indirections could fix that, Oor maybe defunctionalizing thunks into a tagged union, but both sound expensive. Especially without being able to hook into the tracing step for indirection removal.

Also, Haskell supports finalizers so WasmGC would need that as well.

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Just you. Once the editor actually loads (turning the “Haskell source” pane on the left from the page background’s deep violet into a dark gray and displaying a “hello world” program), I can type perfectly fine. And I’m using a browser based on WebKitGTK, which is not exactly known for its stellar compatibility.

I thought you were talking about typing in Haskell at first lol.

I will give a lecture about Haskell next week and might use this website for demonstration.

For one, it demonstrates how far the ghc wasm backend has come, in that such a large system as ghc itself can now run in wasm

yeah why would anyone want to run code on a website

In addition to the other responses, it's also worth noting that wasm itself is useful outside of the web itself; e.g. in containerized applications.

I think the immediate and obvious case would be educational materials. Other than that, technical achievements need not always be practical to be cool :)

Have you ever used Godbolt? The Rust playground? The Typescript's playground? The Go playground?

It lets you have that without the pain of hosting compilers server side.

Compilers are complicated. WASM has been a priority for the Haskell community for a while. Demonstrating GHC's ability to compile itself to WASM is thus a show that it is robust enough to compile a very complicated program into this backen.d

Pandoc is an extremely popular Haskell tool.

We cannot even include it in stagex because there is still literally no way to compile it from source and thus no way to do a real reproducible build, and there is no one left that cares about the language enough to do this.

Honestly it has to be regarded as a dead language until this is resolved.