CoroutineLibrary.cs

using Lua.Runtime;

namespace Lua.Standard;

public sealed class CoroutineLibrary
{
    public static readonly CoroutineLibrary Instance = new();

    public CoroutineLibrary()
    {
        var libraryName = "coroutine";
        Functions =
        [
            new(libraryName, "create", Create),
            new(libraryName, "resume", Resume),
            new(libraryName, "running", Running),
            new(libraryName, "status", Status),
            new(libraryName, "wrap", Wrap),
            new(libraryName, "yield", Yield),
        ];
    }

    public readonly LibraryFunction[] Functions;

    public ValueTask<int> Create(
        LuaFunctionExecutionContext context,
        CancellationToken cancellationToken
    )
    {
        var arg0 = context.GetArgument<LuaFunction>(0);
        return new(context.Return(context.State.CreateCoroutine(arg0, true)));
    }

    public ValueTask<int> Resume(
        LuaFunctionExecutionContext context,
        CancellationToken cancellationToken
    )
    {
        var state = context.GetArgument<LuaState>(0);
        return state.ResumeAsync(
            context with
            {
                ArgumentCount = context.ArgumentCount - 1,
            },
            cancellationToken
        );
    }

    public ValueTask<int> Running(
        LuaFunctionExecutionContext context,
        CancellationToken cancellationToken
    )
    {
        return new(context.Return(context.State, context.State == context.GlobalState.MainThread));
    }

    public ValueTask<int> Status(
        LuaFunctionExecutionContext context,
        CancellationToken cancellationToken
    )
    {
        var state = context.GetArgument<LuaState>(0);
        return new(
            context.Return(
                state.GetStatus() switch
                {
                    LuaThreadStatus.Normal => "normal",
                    LuaThreadStatus.Suspended => "suspended",
                    LuaThreadStatus.Running => "running",
                    LuaThreadStatus.Dead => "dead",
                    _ => "",
                }
            )
        );
    }

    public ValueTask<int> Wrap(
        LuaFunctionExecutionContext context,
        CancellationToken cancellationToken
    )
    {
        var arg0 = context.GetArgument<LuaFunction>(0);
        var state = context.State.CreateCoroutine(arg0, false);
        return new(context.Return(new CSharpClosure("wrap", [state], WrapResume)));
    }

    static ValueTask<int> WrapResume(
        LuaFunctionExecutionContext context,
        CancellationToken cancellationToken
    )
    {
        var state = context.GetCsClosure()!.UpValues[0].Read<LuaState>();
        return state.ResumeWrappedAsync(context, cancellationToken);
    }

    public ValueTask<int> Yield(
        LuaFunctionExecutionContext context,
        CancellationToken cancellationToken
    )
    {
        return context.State.YieldAsync(context, cancellationToken);
    }
}