unity wave spawner script

 using System.Collections;
 using System.Collections.Generic;
 [System.Serializable]
 public class WaveAction
 {
     public string name;
     public float delay;
     public GameObject prefab;
     public int spawnCount;
     public string message;
 }
 [System.Serializable]
 public class Wave
 {
     public string name;
     public List<WaveAction> actions;
 }
 public class WaveGenerator : MonoBehaviour
 {
     public float difficultyFactor = 0.9f;
     public List<Wave> waves;
     private Wave m_CurrentWave;
     public Wave CurrentWave { get { return m_CurrentWave; } }
     private float m_DelayFactor = 1.0f;
 
     IEnumerator SpawnLoop()
     {
         m_DelayFactor = 1.0f;
         while (true)
         {
             foreach (Wave W in waves)
             {
                 m_CurrentWave = W;
                 foreach (WaveAction A in W.actions)
                 {
                     if (A.delay > 0)
                         yield return new WaitForSeconds(A.delay * m_DelayFactor);
                     if (A.message != "")
                     {
                         // TODO: print ingame message
                     }
                     if (A.prefab != null && A.spawnCount > 0)
                     {
                         for (int i = 0; i < A.spawnCount; i++)
                         {
 
                             // Random position within this transform
                             Vector3 rndPosWithin;
                             rndPosWithin = new Vector3(Random.Range(-1f, 1f), Random.Range(-1f, 1f), Random.Range(-1f, 1f));
                             rndPosWithin = transform.TransformPoint(rndPosWithin * .5f);
                             Instantiate(A.prefab, rndPosWithin, transform.rotation);
 
                         }
                     }
                 }
                 yield return null;  // prevents crash if all delays are 0
             }
             m_DelayFactor *= difficultyFactor;
             yield return null;  // prevents crash if all delays are 0
         }
     }
     void Start()
     {
         StartCoroutine(SpawnLoop());
     }
 }