[Question] Access to the lua environment.

[uwukle]

I can't find any information about getting the current environment of the lua being run. I set my environment when lua loads, but I can't get it when a function is executed. Is this possible?

LuaState state = LuaState.Create();

// I create a specific environment so that different blocks of lua code can run independently.
LuaTable environment = new(0, 1);
enviroment["myfunc"] = new LuaFunction("myfunc", MyFunction);

// And now I will set the environment.
LuaClosure closure = state.Load("myfunc()", "anonymous", enviroment);

_ = await state.ExecuteAsync(closure);

private static ValueTask<int> MyFunction(LuaFunctionExecutionContext context, CancellationToken cancellationToken = default)
{
    LuaTable environment = /* I need to get the current environment. */
    // Some code here...
    return new(context.Return());
}

I don't understand the concept of environments at all. Standard functions are loaded through the global environment and are linked to LuaState, but during execution, I can specify my own environment, which won't contain any references to the global one.
To run code in isolation, do I need to create unique LuaStates?

[CodeSmile-0000011110110111]

To run code in isolation, do I need to create unique LuaStates?

If you need/want full isolation, then yes and it would be the easiest way too.

The "environment" is simply the set of global variables, accessible as _G in Lua code or just by using it like any other global variable: test = 123; print(test, _G["test"]) will print 123, 123. See: https://www.lua.org/pil/14.html

In C# glue/callback methods it should be accessible as context.State.Environment.

[uwukle]

In C# glue/callback methods it should be accessible as context.State.Environment.

Yes, but this is the global environment for LuaState, not what I specified when creating LuaClosure.
I meant how to get the specified environment, not the global one.
I'm not using a global environment; without explicitly declaring the _G reference, I can't access the global environment from a script.
I use static C# functions that I then add to Lua. I'd like them to be able to influence environments without explicitly binding them to a specific environment.

Simple example:

using Lua;
using Lua.Runtime;

LuaState state = LuaState.Create();

LuaTable localEnvironment = new(0, 1); 
localEnvironment["myfunc"] = new LuaFunction("myfunc", MyFunction);

LuaClosure closure = state.Load("myfunc()", "anonymous", localEnvironment);

_ = await state.ExecuteAsync(closure);

ValueTask<int> MyFunction(LuaFunctionExecutionContext context, CancellationToken cancellationToken = default)
{
    // Output: false
    Console.WriteLine(context.State.Environment == localEnvironment);
    return new(context.Return());
}

[uwukle]

I can't say I understand how it all works.
But my understanding is that obtaining the environment is impossible, since the function can be run without an environment.

using Lua;

LuaState state = LuaState.Create();

await state.RunAsync(new LuaFunction("myfunc", MyFunction));

static ValueTask<int> MyFunction(LuaFunctionExecutionContext context, CancellationToken cancellationToken = default)
{
    return new(context.Return());
}

When I add a function to a table, I can use its functions like this

myTable:MyFunction()

But when I set this table as the environment, I can't use these functions this way because I can't pass the table as the first argument.
The table is the current environment, but it can't be accessed from C# methods. However, I can access environment variables from within a Lua function that is declared in lua code.

Simply put, I won't be able to replicate this function in C# unless LuaClosure uses a non-global environment.

myint32 = -3

function MyFunction()
    print(myint32 )
end