Consider to native support for WASI and Webassembly？

[JermineHu]

Reference to the following two items:

https://github.com/fastly/lucet

https://github.com/wasmerio/wasmer

[andreabravetti]

It wuold be usefull to have full GUI support with wasm inside a browser

[syrusakbary]

I would love to see V supporting WebAssembly/WASI as a target, with first class support in @wasmerio.
Let us know if we can help in any way! :)

[medvednikov]

Yes, that would be great.

[tomByrer]

Any progress on WASM output please?

[sanathusk]

I would love to see V lang support web assembly.

[richardanaya]

Hey all, I work on a library specifically for enabling WebAssembly languages to communicate with javascript.

http://wasm.js.org/

It might be a way to help accelerate efforts in V to expose more of the host.

[Avey777]

Taking wasi as the compilation target will bring us a lot

[JalonSolov]

A new WASM backend was merged into V last week in PR #17368

You can now compile to WASM and run the code with wasmer

$ v -b wasm examples/wasm/hello_world.v
$ wasmer examples/wasm/hello_world.wasm
Hello WASI!
$

or compile to WASM and run in the browser (see instructions in examples/wasm/mandelbrot directory).

It isn't 100% complete, but there have already been a couple more PRs merged since then to improve the WASM support.

[syrusakbary]

That's awesome @JalonSolov!

[Avey777]

why wasmer ？
How about wasmtime and wasmedge？

[JalonSolov]

... because that's what the person was familiar with that implemented the backend? You are free to try those other options, and if they work, the instructions can be updated to list them as options.

[Avey777]

Why means？

[JalonSolov]

Looks like binaryen didn't get installed correctly. Perhaps it just needs the execute bit set.

[Avey777]

This is trouble.

[km19809]

I have a similar problem. My v cannot find binaryen library, after installing it. I am using Windows 10 and v 0.3.3.

cannot compile `C:\v\cmd\tools\builders\wasm_builder.v`:
==================
C:/Users/km198/AppData/Local/Temp/v_0/wasm_builder.13306416624556646702.tmp.c:67727: warning: assignment from incompatible pointer type
tcc: error: library 'binaryen' not found
...
==================
(Use `v -cg` to print the entire error message)

builder error:
==================
C error. This should never happen.

This is a compiler bug, please report it using `v bug file.v`.

https://github.com/vlang/v/issues/new/choose

You can also use #help on Discord: https://discord.gg/vlang

[JalonSolov]

Try running v cmd/tools/install_binaryen.vsh to get that installed in thirdparty/binaryen.

May still not work for you, but at least it should give the same error others are seeing.

[km19809]

@JalonSolov
It is weird because I already ran it.
Also, I can run binaryen_unittest.exe, which succeeds in all the tests.

[JalonSolov]

Definitely weird, but as stated already... this is a new backend, and hasn't been tested much on Windows - at all - so there are bound to be issues.

[spytheman]

Try with -cc msvc. The CI has a working job with it, see:
https://github.com/vlang/v/blob/master/.github/workflows/wasm_backend_tests_ci.yml#L97