add iterator

Author: 7bitcoder

Library/Iterator.cs

@@ -0,0 +1,34 @@
+public interface IIterator<T>
+{
+    public T Current { get; }
+    public bool IsValid();
+    public IIterator<T> Next();
+
+    public static IIterator<T> operator ++(IIterator<T> it) => it.Next();
+    // public static T operator *(IIterator<T> it) => it.Current;
+    // public static explicit operator bool(IIterator<T> it) => it.IsValid();
+    public static bool operator true(IIterator<T> it) => it.IsValid();
+    public static bool operator false(IIterator<T> it) => !it.IsValid();
+};
+
+public class ListIterator<T> : IIterator<T>
+{
+    private int _index = 0;
+    private List<T> _list;
+    public ListIterator(List<T> list) => _list = list;
+    public T Current => _list[_index];
+    public bool IsValid() => _index >= 0 && _index < _list.Count;
+    public IIterator<T> Next()
+    {
+        _index++;
+        return this;
+    }
+}
+
+public static class ContainerExtensions
+{
+    public static IIterator<T> GetIterator<T>(this List<T> list)
+    {
+        return new ListIterator<T>(list);
+    }
+}

Tests/DependencyInjectorTest/DependencyInjectorTest.cs

@@ -327,5 +327,4 @@ public void ShouldGetArrayTypes()
         uniqueServices.Should().NotBeNull();
         service.Parameters.Should().BeEquivalentTo(uniqueServices);
     }
-
 }

Tests/IteratorTest/IteratorTest.cs

@@ -0,0 +1,19 @@
+using Library;
+
+namespace Tests.DependencyInjectorTest;
+
+public class IteratorTest
+{
+    [Fact]
+    public void ShouldIterateOverList()
+    {
+        var result = new List<int>();
+        var list = new List<int> { 1, 2, 3, 4 };
+        for (var it = list.GetIterator(); it; it++)
+        {
+            result.Add(it.Current);
+        }
+
+        result.Should().BeEquivalentTo(new[] { 1, 2, 3, 4 });
+    }
+}