BadAwaitExpression.cs

Go to the documentation of this file.

using BadScript2.Common;
using BadScript2.Parser.Expressions;
using BadScript2.Runtime;
using BadScript2.Runtime.Error;
using BadScript2.Runtime.Objects;
 
namespace BadScript2.Interop.Common.Task;
 
public class BadAwaitExpression : BadExpression
{
    private readonly BadExpression m_TaskExpr;
 
    public BadAwaitExpression(BadExpression expr, BadSourcePosition position) : base(false, position)
    {
        m_TaskExpr = expr;
    }
 
    public override IEnumerable<BadExpression> GetDescendants()
    {
        return m_TaskExpr.GetDescendantsAndSelf();
    }
 
    protected override IEnumerable<BadObject> InnerExecute(BadExecutionContext context)
    {
        BadObject obj = BadObject.Null;
 
        foreach (BadObject o in m_TaskExpr.Execute(context))
        {
            obj = o;
 
            yield return o;
        }
 
        obj = obj.Dereference();
 
        if (obj is not BadTask task)
        {
            throw new BadRuntimeException("await can only be used on a task", Position);
        }
 
        if (task.IsFinished)
        {
            yield return task.Runnable.GetReturn();
 
            yield break;
        }
 
        BadTaskRunner runner = context.Scope.GetSingleton<BadTaskRunner>() ??
                               throw BadRuntimeException.Create(context.Scope, "Task Runner not found", Position);
 
        //Run Task
        //Add current to continuation
        task.AddContinuation(runner.Current ?? throw new BadRuntimeException("Current task is null", Position));
        runner.Current?.Pause();
 
        if (task.IsInactive)
        {
            runner.AddTask(task, true);
        }
 
        yield return BadObject.Null; //Should pause Here
 
        if (task.Runnable.Error != null)
        {
            throw new BadRuntimeErrorException(task.Runnable.Error);
        }
        else
        {
            yield return task.Runnable.GetReturn();
        }
    }
}