wasi-libc VS WASI

Now there are projects like WASI that allows for interfacing with system resources for WASM code this allows for devs to target WASM runtime for their apps sliding the apps to run locally on any OS without any porting required. This could be a game changer in the future like Docker and containers was in the past decade.

So it doesn’t seem like there has been progress on a pseudo-random number generator function for typst, but there are multiple other ways to solve this: 1. Just don’t. Typst has this functional philosophy, there one input always produces the same output. (not an answer to your question tho) 2. Interface with a webassembly module which has a random number generator. So you could e.g. compile c to wasm and statically link a libc version. You would then just have to export the rand() function. (You could use any lang for this, which has a stdlib with a pseudo random number generator) 3. Implement your own. Random number generators are actually not that hard something like an LCG isn’t to complex. (Id provide an example but im on my phone rn)

Actually WASI[0] will be a better alternative, IIRC extism serialize and deserialize the data that you want to pass every time, adding a lot of overhead.

[0] https://wasi.dev

Actually, it was in wasi-libc: https://github.com/WebAssembly/wasi-libc/blob/main/libc-bott...

Proper isolation in C# is only now becoming a thing, with .Net support for WASI, which is essentially a WebAssembly sandbox which can be given extremely granular privileges (such as access to spefic file system directories, or an effective virtual file system). As an upside, the idea is that it should be possible to write the WASI packages in more or less anything.

Wasm Labs dev here :)

In mod_wasm, there are some differences with a pure CGI implementation. When Apache boots, it loads the configuration and initializes the WasmVM. When a new HTTP request arrives, the VM is ready so you don't need to initialize a different process to manage it.

You still need to process the request and pass the data to the Wasm module. This step is done via STDIN through the WebAssembly System Interface (WASI) implementation [0]. The same happens in the opposite direction, as the module returns the data via STDOUT.

So, the CGI pattern is still there, but it doesn't require new processes and all the code runs in a sandbox.

However this is not the only way you can run a Wasm module. In this specific case, we use CGI via WASI. In other cases, you may compile a module to fulfill a specific API, like ProxyWasm [1] to create HTTP filters for proxies like Envoy.

- [0] https://wasi.dev/

- [1] https://github.com/proxy-wasm/spec

Never done that, but I think you need this: https://wasi.dev/

The Python builds from the WebAssembly language runtimes [0] project target the WebAssembly System Interfaces (WASI) [1]. It allows the Python interpreter to interact with resources like the filesystem.

Many server-side Wasm runtimes supports WASI out of the box. For the browser, you need to provide a polyfill to emulate these resources like the one provided by the WASI team [2].

Regarding SQLite, these builds include libsqlite so you should be able to use it :)

- [0] https://github.com/vmware-labs/webassembly-language-runtimes

- [1] https://wasi.dev/

- [2] https://wasi.dev/polyfill/

Effective debugging results in effective programming; itk-wasm makes effective debugging of WebAssembly possible. In this tutorial, adapted from the itk-wasm documentation, we walk through how to debug a C++ data processing pipeline with the mature, native binary debugging tools that are comfortable for developers. This is a fully featured way to ensure the base correctness of a processing pipeline. Next, we will walk through an interactive debugging experience for WASI WebAssembly. With itk-wasm, we can debug the same source code in either context with an interactive debugger. We also have a convenvient way to pass data from our local filesystem into a WebAssembly (Wasm) processing pipeline.

Communication between the WASM module and the rest of the application needs to be done in very simple types (bytes, ints and floats). No complex types are supported yet. This is why most WASM compilers also provide some glue-code to map between complex types like strings or arrays. The Web Assembly System Interface (WAS) is an on-progress standard aimed to solve this last limitation; once it's mature it will allow easy interoperation with almost every environment. WASI is already available in some WSAM compilers and runtimes.

WASI Co-chair here. Nothing in WASI is "somehow blocked by Google", or indeed blocked by anyone at all. Graphics support in WASI hasn't been developed simply because nobody has put energy into developing graphics support in WASI.

At the end of 2023 we counted around 40 contributors who have been working on WASI specifications and implementations: https://github.com/WebAssembly/meetings/blob/main/wasi/2023/... . That is a great growth for our project from a few years ago when that issue was filed, but as you can see from what people are working on, its all much more foundational pieces than a graphics interface. Also, if you look at who is employing those contributors, its largely vendors who are interested in WASI in the context of serverless. That doesn't mean WASI is limited to only serverless, but that has been the focus from contributors so far.

By rolling out WASI on top of the WASM Component Model we have built a sound foundation for creating WASI proposals that support more problem domains, such as embedded systems (@mc_woods and his colleagues are helping with this), or graphics if someone is interested in putting in the work. Our guide to how to create proposals is found here: https://github.com/WebAssembly/WASI/blob/main/Contributing.m... .

> As I understand it, it's not even really possible today to make WebAssembly do anything meaningful in the browser without trampolining back out to JavaScript anyway, which seems like a remarkable missed opportunity.

That's the underlying messy API it's built on. There are specs to make the API more standardized like https://github.com/WebAssembly/WASI

But overall, yeah, it feels like a shiny new toy everyone is excited about and wants to use. Some toys can be fun to play with, but it doesn't mean we have to rewrite production systems in it. Sometimes, or most of the time, toys don't become useful tools.

Snapshot Preview 1 is the standard all tools are building to right now. The specification is available here: https://github.com/WebAssembly/WASI/blob/main/legacy/preview...

It's pretty unreadable though!

Preview 2 looks like it will be a big change, and is just being finalised at the moment. I'd expect that when preview 2 is available there will be an improvement in the quality of documentation. I'm not sure how long it will take after release for tools to start switching to it. I'd expect Preview 1 will still be the main target at least for the rest of this year.

> Like WTF does this mean? The repo tells me nothing

Directly above the sentence you quoted:

"Interposition in the context of WASI interfaces is the ability for a Webassembly instance to implement a given WASI interface, and for a consumer WebAssembly instance to be able to use this implementation transparently. This can be used to adapt or attenuate the functionality of a WASI API without changing the code using it."

> and I've still yet to see a clear write-up about what WASI is.

In the same document: [0]

> WTF is wit?

The first link in that document ("Starting in Preview2, WASI APIs are defined using the Wit IDL.") is [1].

> I click on "legacy" and I see preview0 and preview1, which are basically unreadable proto-specs.

The README for the legacy directory [2] clearly explains what they are.

> Where's a single well-written WASI spec?

"Development of each API happens in its own repo, which you can access from the proposals list." [3]

> Whatever WASI is doing, I don't like it.

Clearly not - you've gone out of your way to ignore all of the documentation that answers your questions.

> And neither does AssemblyScript team apparently

The AssemblyScript team have a bone to pick with WASI based on their misunderstanding of what WASI is for (it is not intended for use on the web) and WASI's disinterest in supporting UTF-16 strings. You can see for yourself in [4].

[0]: https://github.com/WebAssembly/WASI/tree/main#wasi-high-leve...

The Bytecode Alliance initiated a sub-project called the WebAssembly System Interface (WASI). WASI is an API that allows WebAssembly access to system features such as files, filesystems, Berkeley sockets, clocks, and random numbers. WASI acts as a system-level interface for WebAssembly, so incorporating a runtime into a host environment and building a platform is easier.

We are excited to contribute back to Wasmtime and the component model, as well as to new projects and proposals emerging in this space (such as new Wasm proposals, like WASI Preview 2, wasi-keyvalue, wasi-sql or wasi-cloud).

I've been reading the following repositories.

https://github.com/WebAssembly/WASI/blob/main/Proposals.md