luau VS tl

As far as I can tell, they aren't.

http://lua-users.org/wiki/SandBoxes

There is a lot of information there, but it doesn't handle resource exhaustion, execution time limits or give any guarantees. It does indicate that it's possible, and has a decent example of the most restrictive setup, which is a good start. But I would for example compare it with Luau's SECURITY.md.

From https://github.com/luau-lang/luau/blob/master/SECURITY.md:

> Luau provides a safe sandbox that scripts can not escape from, short of vulnerabilities in custom C functions exposed by the host. This includes the virtual machine and builtin libraries. Notably this currently does not include the work-in-progress native code generation facilities.

> Any source code can not result in memory safety errors or crashes during its compilation or execution. Violations of memory safety are considered vulnerabilities.

> Note that Luau does not provide termination guarantees - some code may exhaust CPU or RAM resources on the system during compilation or execution.

So, even luau will have trouble with untrusted code, but it specifies exactly what happens and so on. I think that's fair enough.

Alternatively, Luau is a well-supported Lua variant with type checking and performance improvements, aimed more towards being a sandboxed embedded scripting environment.

https://luau-lang.org/

If you need Lua but also type-safety, how about Luau [1] then?

[1] https://luau-lang.org/

I had the pleasure of working with Lua 5.1 back in the late noughties. For me it's replaced Tcl whenever I want something I can configure above a C library. At the time I used it I found it quite nice but I'll also not forget the hours I wasted tracking down nil table corruptions which could have easily been caught by a type checker.

I had some hope that Luau https://luau-lang.org or Teal https://github.com/teal-language/tl would make things better but with the following example

    function foo(x: number): string

Looking at other replies here, I can see I wasn't the only one who didn't realize there is Lua and Luau. Luau is an extension of Lua: https://luau-lang.org/

> Luau is syntactically backwards-compatible with Lua 5.1 (code that is valid Lua 5.1 is also valid Luau); however, we have extended the language with a set of syntactical features that make the language more familiar and ergonomic.

Lua is usually the embedded language of choice. If you are focused on security, you could check out the Roblox fork, Luau (https://github.com/Roblox/luau) where the creators took extra care to lock down the language on what scripts could do.

Luau - Lua variant by Roblox

On a side note, I've heard that they recently switched from Lua to Roblox's own fork of Lua, Luau.

https://www.youtube.com/results?search_query=luau+roblox&sp=...

Luau

https://github.com/Roblox/luau

Roblox wrote a superset of Roblox Lua which is way faster

https://luau-lang.org/ - some documentation, and examples https://create.roblox.com/docs - documentation, tutorials, and examples https://www.youtube.com/user/AlvinBLOX - tutorials https://www.youtube.com/@TheDevKing/videos - tutorials https://www.lua.org/manual/5.1/ - not specific to Roblox, but Lua reference manual https://www.codecademy.com/learn/learn-lua - Lua on Codecademy

it's based off MIR, does it have something to do with https://mlir.llvm.org/ ?

for typed lua, there is another effort https://github.com/teal-language/tl in addition to the mentioned typescript approach: https://github.com/andremm/typedlua

I had the pleasure of working with Lua 5.1 back in the late noughties. For me it's replaced Tcl whenever I want something I can configure above a C library. At the time I used it I found it quite nice but I'll also not forget the hours I wasted tracking down nil table corruptions which could have easily been caught by a type checker.

I had some hope that Luau https://luau-lang.org or Teal https://github.com/teal-language/tl would make things better but with the following example

    function foo(x: number): string

I wonder why the author doesn't use Teal [0] - a typed dialect of lua.

[O] https://github.com/teal-language/tl

Check out Teal

There is already https://github.com/teal-language/tl, which is typed Lua. I think fennel exists to serve a different niche-- personally I use it not for any type features; I just like the syntax better, and others may find certain features like the macro system useful.

There's also some languages made to compile straight to Lua: - MoonScript is the most popular Lua wrapper - it's built to be more Python-like, featuring indentation-based scopes, function calls without parentheses, lambda syntax, list comprehension, and much more. - Yuescript is a modern update to MoonScript that adds more features (I haven't used it myself, so I'm not entirely sure exactly how it differs from MS). - Teal is a version of Lua that adds static typing for better code standards.

Terra and Nelua are both very different in goals than Teal. Teal is literally gradual types integrated into Lua keeping as many of Lua's idioms as possible (to a fault[1]). Terra and Nelua are both very metaprogrammable systems programming languages. Nelua's goals are primarily to soften C's rough edges, comparable to something like Nim.

There's another one you missed in Pallene[2]. But again, it's goal was to optimize the stack sharing involved in using the C API. It also adds types though and maintains Lua idioms as much as possible.

[1]: https://github.com/teal-language/tl/discussions/339

[2]: https://github.com/pallene-lang/pallene