diff --git a/BeefLibs/corlib/src/Range.bf b/BeefLibs/corlib/src/Range.bf
index ce3301e2..4fe7bdda 100644
--- a/BeefLibs/corlib/src/Range.bf
+++ b/BeefLibs/corlib/src/Range.bf
@@ -79,10 +79,29 @@ namespace System
 				return mEnd == mStart;
 			}
 		}
+
+		public ReverseEnumerator Reversed
+		{
+			[Inline]
+			get
+			{
+				return ReverseEnumerator(mEnd - 1, mStart);
+			}
+		}
 		
 		public bool Contains(int idx)
 		{
-			return (idx >= mStart) && (idx < mStart);
+			return (idx >= mStart) && (idx < mEnd);
+		}
+
+		public bool Contains(Range val)
+		{
+			return (val.[Friend]mStart >= mStart) && (val.[Friend]mEnd <= mEnd);
+		}
+
+		public bool Contains(ClosedRange val)
+		{
+			return (val.[Friend]mStart >= mStart) && (val.[Friend]mEnd <= mEnd - 1);
 		}
 
 		public void Clear() mut
@@ -135,7 +154,41 @@ namespace System
 					return .Err;
 				return ++mIndex;
 			}
+		}
 
+		public struct ReverseEnumerator : IEnumerator<int>
+		{
+		    private int mEnd;
+		    private int mIndex;
+
+			[Inline]
+		    public this(int start, int end)
+		    {
+		        mIndex = start + 1;
+		        mEnd = end;
+		    }
+
+		    public void Dispose()
+		    {
+		    }
+
+		    public ref int Index
+		    {
+		        get mut
+		        {
+		            return ref mIndex;
+		        }
+		    }
+
+			public int End => mEnd;
+
+			[Inline]
+			public Result<int> GetNext() mut
+			{
+				if (mIndex <= mEnd)
+					return .Err;
+				return --mIndex;
+			}
 		}
 	}
 
@@ -210,10 +263,29 @@ namespace System
 				return mEnd == mStart;
 			}
 		}
+
+		public Range.ReverseEnumerator Reversed
+		{
+			[Inline]
+			get
+			{
+				return Range.ReverseEnumerator(mEnd, mStart);
+			}
+		}
 		
 		public bool Contains(int idx)
 		{
-			return (idx >= mStart) && (idx < mStart);
+			return (idx >= mStart) && (idx <= mEnd);
+		}
+
+		public bool Contains(Range val)
+		{
+			return (val.[Friend]mStart >= mStart) && (val.[Friend]mEnd - 1 <= mEnd);
+		}
+
+		public bool Contains(ClosedRange val)
+		{
+			return (val.[Friend]mStart >= mStart) && (val.[Friend]mEnd <= mEnd);
 		}
 
 		public void Clear() mut
diff --git a/IDEHelper/Tests/src/Loops.bf b/IDEHelper/Tests/src/Loops.bf
index 864ca3cc..c9a80c83 100644
--- a/IDEHelper/Tests/src/Loops.bf
+++ b/IDEHelper/Tests/src/Loops.bf
@@ -2,6 +2,7 @@
 
 using System;
 using System.Collections;
+using System.Diagnostics;
 
 namespace Tests
 {
@@ -75,13 +76,63 @@ namespace Tests
 
 			int total = 0;
 			for (int i in 1..<10)
+			{
+				if (i == 5)
+					Test.Assert(total == 1+2+3+4);
 				total += i;
+			}
 			Test.Assert(total == 1+2+3+4+5+6+7+8+9);
 
 			total = 0;
 			for (int i in 1...10)
+			{
+				if (i == 5)
+					Test.Assert(total == 1+2+3+4);
 				total += i;
+			}
 			Test.Assert(total == 1+2+3+4+5+6+7+8+9+10);
+
+			total = 0;
+			for (int i in (1..<10).Reversed)
+			{
+				if (i == 5)
+					Test.Assert(total == 9+8+7+6);
+				total += i;
+
+			}
+			Test.Assert(total == 9+8+7+6+5+4+3+2+1);
+
+			total = 0;
+			for (int i in (1...10).Reversed)
+			{
+				if (i == 5)
+					Test.Assert(total == 10+9+8+7+6);
+				total += i;
+
+			}
+			Test.Assert(total == 10+9+8+7+6+5+4+3+2+1);
+
+			Test.Assert(!(1...3).Contains(0));
+			Test.Assert((1...3).Contains(1));
+			Test.Assert((1...3).Contains(2));
+			Test.Assert((1...3).Contains(3));
+			Test.Assert(!(1...3).Contains(4));
+
+			Test.Assert(!(1..<3).Contains(0));
+			Test.Assert((1..<3).Contains(1));
+			Test.Assert((1..<3).Contains(2));
+			Test.Assert(!(1..<3).Contains(3));
+
+			Test.Assert((1...3).Contains(1...3));
+			Test.Assert((1...3).Contains(1...2));
+			Test.Assert(!(1...3).Contains(1...4));
+			Test.Assert((1...3).Contains(2..<3));
+			Test.Assert((1...3).Contains(2..<4));
+			Test.Assert(!(1...3).Contains(2..<5));
+			Test.Assert(!(1..<3).Contains(1...3));
+			Test.Assert((1..<3).Contains(1..<3));
+			Test.Assert(!(1..<3).Contains(1..<4));
+
 		}
 
 		public static void TestEnumerator1(EnumeratorTest e)