Unity3D Coroutine compiler error

Question

I'm a complete beginner in unity, and i'm tring to play an animation with a coroutine, but get the following erros:

1.error CS1502: The best overloaded method match for UnityEngine.MonoBehaviour.StartCoroutine(System.Collections.IEnumerator)' has some invalid arguments 2.error CS1503: Argument #1' cannot convert System.Collections.IEnumerable' expression to type System.Collections.IEnumerator'

---

The code:

     using UnityEngine;
using System.Collections;

public class Trap : MonoBehaviour {

    //public float delayTime;


    // Use this for initialization
    void Start () {
        StartCoroutine (Go ());
    }

    // Update is called once per frame
    void Update () {

    }

    IEnumerable Go(){
        while (true) {
            animation.Play();
            yield return new WaitForSeconds(3f);
        }
    }

}

Answer 1

change

IEnumerable Go(){
    while (true) {
        animation.Play();
        yield return new WaitForSeconds(3f);
    }
}

for a IEnumerator...

IEnumerator Go(){
    while (true) {
        animation.Play();
        yield return new WaitForSeconds(3f);
    }
}

Answer 2

协程的返回类型将是IEnumerator。