otto VS gc

robertkrimen/otto

Ummm, excuse me, but where the f&$k has this been hiding? I’ve been looking for ways to extend my go applications with scripting support. I started with Lua (worked ) then Python (worked but hacky) then javascript using otto [1]. However it lacks ES6 support so having pretty OOP js code is a non-starter. I would love to have Java as a runtime that can be executed from goroutines.

[1] https://github.com/robertkrimen/otto

Either call a JavaScript interpreter like node with exec.Command and read its stdout, or use a pure Go JavaScript interpreter like goja or otto.

Otto https://github.com/robertkrimen/otto Seems interesting. It lets me call Go functions from inside JS as well as return results. The fncs pattern reminds me a bit of how the template engine works.

> why host other languages

Here's an example:

I recently finished building https://subzo.com.au which allows customizing and ordering 3D models. The way the model's cost, volume and other attributes are calculated needs to be done both on the frontend (for speed) and on the backend (to validate). Backend is in Go and we can't practically run Go in the browser. So instead, I wrote the calculation snippets in JavaScript (which runs natively in the browser) and ran them on the backend on a JavaScript VM library written in Go [1].

[1]: https://github.com/robertkrimen/otto

Googling suggests https://github.com/robertkrimen/otto which allows scripting in javascript for golang projects. This would be definitely enough, but in some way it may be a bit overkill - and scripts supporter shall need some knowledge of javascript which is not always straightforward :)

It doesn't make sense to ask the user (aka me) to change the code every time I want to modify any web apps right? So I decided to split the webapps into two parts. WebApps are those only require basic permissions and do not interact with the host OS. They will be run inside a sandbox created using ECMA5 VM called Otto. The other type is called Subservice, in which it will need extra permission to interact with the OS and require higher level of access to the backend file system.

It may take some time for WasmGC to be usable by .NET. Based on the discussions the first version of WasmGC does not have a good way to handle a few .NET specific scenarios, and said scenarios are "post-post-mvp". [0]

My concern, of course, is that there is not much incentive for those features to be added if .NET is the only platform that needs them... at that point having a form of 'include' (to where a specific GC version can just be cached and loaded by another WASM assembly) would be more useful, despite the pain it would create.

[0] - https://github.com/WebAssembly/gc/issues/77

Yes, that's definitely true: a single GC will not be optimal for everything, or even possible. Atm interior pointers are not supported at all, for example, but they are on the roadmap for later:

https://github.com/WebAssembly/gc/blob/main/proposals/gc/Pos...

What launched now is enough WasmGC to support a big and useful set of languages (Java, Kotlin, Dart, OCaml, Scheme), but a lot more work will be required here!

GC proposal is from 2018: https://github.com/WebAssembly/proposals/issues/16 and there’s code: https://github.com/WebAssembly/gc/blob/master/proposals/gc/O...

Seems like an awefully long time for progress to be made, given all the possibilities it would unlock.

First is the size. Writing a server-side and client-side program is possible with Rust, and the resulting WASM package will be small enough. At the same time, Microsoft Blazor converts C# code to WASM, but the client delivery has to include the reduced .NET runtime, taking several megabytes for a script. The same is true for GoLang, even with an attempt to reduce the runtime delivery in TinyGo WASM. Developers want to work with their favorite languages, whether it is Java, Kotlin, Dart, C#, F#, Swift, Ruby, Python, C, C++, GoLang, or Rust. These languages produce groups of runtimes. For example, JVM and .NET have many common parts, Ruby and Python are dynamically interpreted at runtime, and all mentioned depend on automatic garbage collection. For smaller WASM packages, browser vendors can include extended runtime implementations, for example, by delivering a general garbage collector as part of WASM. Garbage collection support by WASM is currently in progress: WASM GC, .NET WASM Notes.

My understanding is that the main limitation is technical. WASM doens't do GC or the host system calling conventions and cannot interact directly with object from Javascript because of this. However, this is being worked[0] on and will be solved eventually. Even without this the performance overhead of bridging to JS is low enough that WASM frameworks can beat out React.

0: https://github.com/WebAssembly/gc/blob/main/proposals/gc/Ove...

I’ve just watched a video on YouTube from Google I/O 2023 on Flutter for the web. Kevin Moore explains that Flutter can compile to Wasm, but now that GC support has been added to the standard and WasmGC is supported in Chromium and Firefox, I’m quite intrigued.

I have found the main thread about using WebAssembly GC in C#: https://github.com/WebAssembly/gc/issues/77. If I understand it correctly, it is not possible to use the current prototype version of GC in C#.

The .net team has given their notes on it, the concern is more on the memory layout from what I remember. Though it may be possible still. The runtime would likely still ship some gc code, but only a subset for cases not supported by the wasm gc itself and a few more for interfacing with the gc service, which overall should still result on smaller payloads compared to current sizes.

I assume that's one of the parts of the work done at https://github.com/WebAssembly/gc - not happening any soon yet, but it'll eventually be done.