Luau support

[Milo123459]

https://luau-lang.org/

[khvzak]

Luau does not support object finalizers (__gc metamethod) that makes it impossible to use with Rust.

[Milo123459]

Oh. Is there no work around?

[khvzak]

By the way, I cannot find link to download Luau source code. Apparently it's a commercial product not publicly available.

[Milo123459]

I think there is a luau compiler?

[Milo123459]

Or - just use Lua 5.1 and add the type system.

[Milo123459]

https://github.com/Roblox/luau has now been opensourced.

[khvzak]

This is great news, I'll take a look, thanks!

[Milo123459]

Any updates? Hate to bump, but genuinely curious.

[khvzak]

No news yet. Luau is very different from vanilla Lua and couple of weeks ago even didn't have C interface.
Although I'm not sure about the current status of C interface (how usable is it).

[khvzak]

Just curious, is there any advantages to use Luau instead of normal Lua or luajit?

[Milo123459]

To be honest, I like using it for the types. It has TypeScript like types, which makes me more or less feel at home with it.

[ildar]

Typed Lua aka Teal might satisfy you with it.

[Milo123459]

There are also some other beta-features that I would like to use in Luau. Still, Teal does satisfy me (I use it a lot) this would be cool, still.

[grilme99]

Luau support would be great.

Just curious, is there any advantages to use Luau instead of normal Lua or luajit?

This is covered in their docs but essentially the tl;dr is that it is progressively typed and the performance is on-par with LuaJIT in certain cases and outperforms standard Lua in all cases. Roblox could never use JIT themselves because certain target platforms either do not support it or do now allow it (e.g. Apple with iOS).

It's based on Lua 5.1 but sprinkles in some of the best parts of later Lua versions. Luau has an amazing sandbox built-in which can guarantee* safety, even when running completely arbitrary and actively malicious code - perfect for game mods etc. The sandbox also has support for interrupts, which is pretty nice.

[khvzak]

I pushed initial Luau support to the dev branch
It passes tests and works in vendored only mode by default.

So the next mlua v0.8 will get luau support including emulating some of the missed features like userdata values, require, etc.