Brian Carroll (Aug 10 2021 at 23:01): Brian Carroll (Aug 10 2021 at 23:01):Hey just seeing this discussion on Wasm. In my Elm-in-Wasm project I originally built a back end that went directly to Wasm. But later I decided to go through C to make it easier to debug, and I could have kernel code in the C too, etc. Anyway I have a good understanding of how the instruction set works and that kind of thing, if that can be of use to people.
Brian Carroll (Aug 10 2021 at 23:04):Regarding .wasm and .wat formats, there's a WebAssembly Binary Toolkit that has some useful tools including translating back and forth between the two.
Brian Carroll (Aug 10 2021 at 23:04):There's also an optimizer there
Folkert de Vries (Aug 10 2021 at 23:08):are there rust bindings for that? I thought wasm was pretty rust-centered but maybe not?
Brian Carroll (Aug 10 2021 at 23:08):The Wasm module is a data structure that I think more or less resembles an executable file like ELF or EXE. It has a data section and code sections and some tables and that kind of thing. Best resource I found for this was the spec itself, although that was a couple of years ago, maybe there's better stuff now. But this page shows you the module structure: https://webassembly.github.io/spec/core/syntax/modules.html
Brian Carroll (Aug 10 2021 at 23:09):No I definitely wouldn't say Wasm is Rust-centred! If anything maybe the other way around
Brian Carroll (Aug 10 2021 at 23:09):Rust does have good support for it
Brian Carroll (Aug 10 2021 at 23:10):But a lot of the actual Wasm development is more geared towards C and C++. And if you're using LLVM anyway then that has a Wasm back end so that would be the way to do it. Zig has a Wasm back end.
Brian Carroll (Aug 10 2021 at 23:14):I didn't use Rust for my project, only C. I did a tiny amount with Rust and Wasm like 2 or 3 years ago but can't remember now.
Brian Carroll (Aug 10 2021 at 23:15):I did create a Haskell type definition to represent the Wasm module though
Folkert de Vries (Aug 10 2021 at 23:15):well sure we can go to wasm via llvm, but llvm is very slow
Folkert de Vries (Aug 10 2021 at 23:15):which is why we're also working on direct assembly backends
Folkert de Vries (Aug 10 2021 at 23:16):and would similarly ultimately like to emit wasm directly, for development purposes (a release/optimized build would still probably go via LLVM)
Brian Carroll (Aug 10 2021 at 23:16):Right, I see
Richard Feldman (Aug 11 2021 at 01:39):(moved this to its own topic!)
Richard Feldman (Aug 11 2021 at 01:40):thanks for the wasm tips, Brian! :smiley:
Brian Carroll (Aug 11 2021 at 08:09):Sure!
Looks like there are indeed Rust bindings for WABT, and it has struct definitions for a Wasm module etc. https://docs.rs/wabt/0.10.0/wabt/
Ally Jr Salim (Mar 30 2025 at 00:51):Hey all! Getting started with roc and having trouble with compiling to wasm. Is there a simple (relatively recent) example of this? Is there a dedicated wasm platform?
I have found repos that are 2 years old, using zig, but I think the wasm story is much better now. Any examples / references would be appreciated!
Thanks
Brendan Hansknecht (Mar 30 2025 at 04:46):I think most wasm platforms have been bespoke made for single apps. I don't think we have any flexible platforms. That said, we may have more recent examples. Oh, I guess, wasm4 is technically slightly flexible and wasm, but it isn't hooked into the browser directly. It is for a game engine.
Vladimir Zotov (Mar 30 2025 at 13:03):There is an example of compilation to wasm (frontend stuff though)
https://github.com/lukewilliamboswell/roc-experiment-js-dom/blob/a0bf524d1d80ff8a36128611aa4de21c6d465bf7/run-web.sh#L15
Last updated: Jul 26 2025 at 12:14 UTC