Unity Coroutine with Generic Result

Provides a replacement for Unity game engine coroutines that can return a generic result, mostly used in a similar manner to UnityEngine.Coroutine.

Usage

To use the Coroutine<T> class, follow these steps:

1. Ensure that you have a reference to a MonoBehaviour instance.
2. Call the StartCoroutine<T> extension method on your MonoBehaviour instance. (Note that this. is required to use an extension method in C#.)
3. Pass the routine you want to execute as an IEnumerator parameter.
4. Cast the Coroutine<T> to a UnityEngine.Coroutine to wait for execution.
5. Access the .Result.

using System;
using System.Collections;
using UnityEngine;

public class CoroutineExample : MonoBehaviour
{ 
    private IEnumerator Start()
    {
        // Start the coroutine
        Coroutine<int> coroutine = this.StartCoroutine<int>(YourRoutine());

        // Wait for the coroutine to complete by casting to a UnityEngine.Coroutine
        yield return (Coroutine)coroutine;

        try
        {
            // Access the result of the coroutine
            int result = coroutine.Result;
            Debug.Log("Coroutine result: " + result);
        }
        catch (ApplicationException exception)
        {
            // Handle any excpetion
            Debug.LogError("Coroutine exception: " + exception.Message);
        }
    }

    private IEnumerator YourRoutine()
    {
        // Your coroutine logic here
        yield return new WaitForSeconds(2);

        // Exceptions will be re-thrown
        if (UnityEngine.Random.value < 0.5f)
        {
            throw new ApplicationException("Something went wrong in the coroutine!");
        }

        yield return 42;
    }
}

In the example above, a coroutine YourRoutine is started using the StartCoroutine<int> extension method. The result of the coroutine is accessed using the Result property of the Coroutine<int> object.

Exceptions

Exception will be thrown if any of these circumstances are true:

• Attempting to access the result of a coroutine before it has yielded a result will throw an InvalidOperationException.
• After a coroutine is cancelled with .Cancel(), attempting to access the result will throw an OperationCanceledException.
• If the coroutine throws an exception during execution, the Coroutine<T> object will capture and re-throw the exception when the result is accessed.

API Reference

MonoBehaviourExtension

A static class that extends the MonoBehaviour class with the StartCoroutine<T> extension method.

Methods

• StartCoroutine<T>(this MonoBehaviour monoBehaviour, IEnumerator routine): Starts a coroutine and returns a Coroutine<T> object.

Coroutine<T>

A class that represents a coroutine with a result.

Properties

• Result: The result of the coroutine. Accessing this property will throw an exception if the coroutine has not yielded a result yet.
• Cancel(): Cancels the execution of the coroutine.
• implicit operator UnityEngine.Coroutine: Allows implicit conversion from Coroutine<T> to UnityEngine.Coroutine.

License

This code is provided under the MIT License. Feel free to modify and use it in your projects.