Rework for loops to use iterators, requiring pairs or ipairs function to handle multi-assignment

Upsilon/BaseTypes/UserData/ListUserData.cs

@@ -1,5 +1,7 @@
+using System;
 using System.Collections;
 using System.Collections.Generic;
+using Upsilon.BaseTypes.Number;
 using Upsilon.BaseTypes.ScriptTypeInterfaces;
 using Upsilon.Evaluator;
 using Upsilon.Text;
@@ -51,9 +53,18 @@ namespace Upsilon.BaseTypes.UserData
             return List.GetType();
         }
 
-        public IEnumerator<(string Key, ScriptType value)> GetEnumerator()
+        public ScriptType GetValueFromIndex(ScriptType index)
         {
-            throw new System.NotImplementedException();
+            var num = (ScriptNumberLong)index;
+            return List[(int) num.Value].ToScriptType();
+        }
+
+        public IEnumerator<ScriptType> GetEnumerator()
+        {
+            for (int i = 0; i < List.Count; i++)
+            {
+                yield return new ScriptNumberLong(i);
+            }
         }
     }
 }