diff --git a/BeefLibs/corlib/src/Collections/Dictionary.bf b/BeefLibs/corlib/src/Collections/Dictionary.bf
index 32fca56a..7313d931 100644
--- a/BeefLibs/corlib/src/Collections/Dictionary.bf
+++ b/BeefLibs/corlib/src/Collections/Dictionary.bf
@@ -258,21 +258,9 @@ namespace System.Collections
 
 		public bool ContainsValue(TValue value)
 		{
-			if (value == null)
+			for (int_cosize i = 0; i < mCount; i++)
 			{
-				for (int_cosize i = 0; i < mCount; i++)
-				{
-					if (mEntries[i].mHashCode >= 0 && mEntries[i].mValue == null) return true;
-				}
-			}
-			else
-			{
-				//TODO: IMPORTANT!
-				/*EqualityComparer<TValue> c = EqualityComparer<TValue>.Default;
-				for (int i = 0; i < count; i++)
-				{
-					if (entries[i].hashCode >= 0 && c.Equals(entries[i].value, value)) return true;
-				}*/
+				if (mEntries[i].mHashCode >= 0 && mEntries[i].mValue == null) return true;
 			}
 			return false;
 		}
diff --git a/BeefLibs/corlib/src/Collections/List.bf b/BeefLibs/corlib/src/Collections/List.bf
index 605cb723..90423812 100644
--- a/BeefLibs/corlib/src/Collections/List.bf
+++ b/BeefLibs/corlib/src/Collections/List.bf
@@ -930,6 +930,59 @@ namespace System.Collections
 		}
 	}
 
+	extension List<T> where T : String
+	{
+		public bool Contains(T item, StringComparison comparison)
+		{
+			if (item == null)
+			{
+			    for (int i = 0; i < mSize; i++)
+			        if (mItems[i] == null)
+			    		return true;
+			    return false;
+			}
+			else
+			{
+				for (int i = 0; i < mSize; i++)
+					if (mItems[i].Equals(item, comparison))
+						return true;
+			    return false;
+			}
+		}
+
+		public int IndexOf(T item, StringComparison comparison)
+		{
+			for (int i = 0; i < mSize; i++)
+				if (mItems[i].Equals(item, comparison))
+					return i;
+			return -1;
+		}
+
+		public int IndexOf(T item, int index, StringComparison comparison)
+		{
+			for (int i = index; i < mSize; i++)
+				if (mItems[i].Equals(item, comparison))
+					return i;
+			return -1;
+		}
+
+		public int IndexOf(T item, int index, int count, StringComparison comparison)
+		{
+			for (int i = index; i < index + count; i++)
+				if (mItems[i].Equals(item, comparison))
+					return i;
+			return -1;
+		}
+
+		public int LastIndexOf(T item, StringComparison comparison)
+		{
+			for (int i = mSize - 1; i >= 0; i--)
+				if (mItems[i].Equals(item, comparison))
+					return i;
+			return -1;
+		}
+	}
+
 	class ListWithAlloc<T> : List<T>
 	{
 		IRawAllocator mAlloc;
diff --git a/BeefLibs/corlib/src/Diagnostics/Check.bf b/BeefLibs/corlib/src/Diagnostics/Check.bf
index 0b26b71c..b041f6fb 100644
--- a/BeefLibs/corlib/src/Diagnostics/Check.bf
+++ b/BeefLibs/corlib/src/Diagnostics/Check.bf
@@ -1,6 +1,6 @@
 namespace System.Diagnostics
 {
-	class Check
+	static class Check
 	{
 
 		[Unchecked, SkipCall]
diff --git a/BeefLibs/corlib/src/Diagnostics/Contracts/Contracts.bf b/BeefLibs/corlib/src/Diagnostics/Contracts/Contracts.bf
index e14d5a0c..e5f7d80c 100644
--- a/BeefLibs/corlib/src/Diagnostics/Contracts/Contracts.bf
+++ b/BeefLibs/corlib/src/Diagnostics/Contracts/Contracts.bf
@@ -1,6 +1,6 @@
 namespace System.Diagnostics.Contracts
 {
-    class Contract
+    static class Contract
     {
         public enum ContractFailureKind
         {
diff --git a/BeefLibs/corlib/src/Diagnostics/Debug.bf b/BeefLibs/corlib/src/Diagnostics/Debug.bf
index d4df7bd4..fe45865b 100644
--- a/BeefLibs/corlib/src/Diagnostics/Debug.bf
+++ b/BeefLibs/corlib/src/Diagnostics/Debug.bf
@@ -1,6 +1,6 @@
 namespace System.Diagnostics
 {
-	class Debug
+	static class Debug
 	{
 #if !DEBUG
 		[SkipCall]
diff --git a/BeefLibs/corlib/src/IO/File.bf b/BeefLibs/corlib/src/IO/File.bf
index a3ae6cf2..06d6abd7 100644
--- a/BeefLibs/corlib/src/IO/File.bf
+++ b/BeefLibs/corlib/src/IO/File.bf
@@ -23,7 +23,7 @@ namespace System.IO
 		case FileReadError(FileReadError);
 	}
 
-	class File
+	static class File
 	{
 		public static Result<void, FileError> ReadAll(StringView path, List<uint8> outData)
 		{
diff --git a/BeefLibs/corlib/src/IO/Stream.bf b/BeefLibs/corlib/src/IO/Stream.bf
index 6798c4aa..00e8bab5 100644
--- a/BeefLibs/corlib/src/IO/Stream.bf
+++ b/BeefLibs/corlib/src/IO/Stream.bf
@@ -97,10 +97,10 @@ namespace System.IO
 			}
 		}
 
-		//Read sized string from stream
-		public Result<void> ReadStrSized32(int64 size, String output)
+		/// Read sized string from stream
+		public Result<void> ReadStrSized32(int size, String output)
 		{
-			if (size <= 0)
+			if (size < 0)
 				return .Err;
 
 			for (int64 i = 0; i < size; i++)
@@ -115,7 +115,13 @@ namespace System.IO
 			return .Ok;
 		}
 
-		//Reads null terminated ASCII string from the stream. Null terminator is read from stream but isn't appended to output string
+		public Result<void> ReadStrSized32(String output)
+		{
+			int size = Try!(Read<int32>());
+			return ReadStrSized32(size, output);
+		}
+
+		/// Reads null terminated ASCII string from the stream. Null terminator is read from stream but isn't appended to output string
 		public Result<void> ReadStrC(String output)
 		{
 			Result<char8> char0;
diff --git a/BeefLibs/corlib/src/Runtime.bf b/BeefLibs/corlib/src/Runtime.bf
index 96ae54fc..564b032c 100644
--- a/BeefLibs/corlib/src/Runtime.bf
+++ b/BeefLibs/corlib/src/Runtime.bf
@@ -6,7 +6,7 @@ using System.Threading;
 namespace System
 {
 	[StaticInitPriority(100)]
-	class Runtime
+	static class Runtime
 	{
 		const int32 cVersion = 8;
 
diff --git a/BeefLibs/corlib/src/System.bf b/BeefLibs/corlib/src/System.bf
index def9c456..9289da0a 100644
--- a/BeefLibs/corlib/src/System.bf
+++ b/BeefLibs/corlib/src/System.bf
@@ -227,6 +227,26 @@ static
 		}
 	}
 
+	public static mixin DeleteContainerAndDisposeItems(var container)
+	{
+		if (container != null)
+		{
+			for (var value in container)
+				value.Dispose();
+			delete container;
+		}
+	}
+
+	public static mixin ClearAndDisposeItems(var container)
+	{
+		if (container != null)
+		{
+			for (var value in container)
+				value.Dispose();
+			container.Clear();
+		}
+	}
+
 	public static mixin DeleteAndNullify(var val)
 	{
 		delete val;
diff --git a/BeefLibs/corlib/src/Text/UTF16.bf b/BeefLibs/corlib/src/Text/UTF16.bf
index 4a4953f2..5ab1fc6d 100644
--- a/BeefLibs/corlib/src/Text/UTF16.bf
+++ b/BeefLibs/corlib/src/Text/UTF16.bf
@@ -1,7 +1,7 @@
 using System.Diagnostics;
 namespace System.Text
 {
-	public class UTF16
+	public static class UTF16
 	{
 		public enum EncodeError
 		{
diff --git a/BeefLibs/corlib/src/Text/UTF8.bf b/BeefLibs/corlib/src/Text/UTF8.bf
index 4df4c7f9..0dce24ae 100644
--- a/BeefLibs/corlib/src/Text/UTF8.bf
+++ b/BeefLibs/corlib/src/Text/UTF8.bf
@@ -1,7 +1,7 @@
 using System.Diagnostics;
 namespace System.Text
 {
-	class UTF8
+	static class UTF8
 	{
 		public const int8[256] sTrailingBytesForUTF8 =
 		.(
diff --git a/BeefLibs/corlib/src/Type.bf b/BeefLibs/corlib/src/Type.bf
index 73d6acf1..d8b60c6c 100644
--- a/BeefLibs/corlib/src/Type.bf
+++ b/BeefLibs/corlib/src/Type.bf
@@ -683,13 +683,7 @@ namespace System
 
 namespace System.Reflection
 {
-    public struct TypeId : int32
-    {
-        public Type ToType()
-        {
-            return Type.[Friend]sTypes[(int32)this];
-        }        
-    }
+    public struct TypeId : int32 {}
 
     [Ordered, AlwaysInclude(AssumeInstantiated=true)]
     public class TypeInstance : Type
@@ -1137,7 +1131,7 @@ namespace System.Reflection
 
 		public Type GetGenericArg(int argIdx)
 		{
-			return mResolvedTypeRefs[argIdx].ToType();
+			return Type.GetType(mResolvedTypeRefs[argIdx]);
 		}
 
 		public override void GetFullName(String strBuffer)
diff --git a/IDE/src/ui/SourceEditWidgetContent.bf b/IDE/src/ui/SourceEditWidgetContent.bf
index cbef21bb..784a2484 100644
--- a/IDE/src/ui/SourceEditWidgetContent.bf
+++ b/IDE/src/ui/SourceEditWidgetContent.bf
@@ -2758,7 +2758,7 @@ namespace IDE.ui
 				return;
 			}
 
-            if (mIsReadOnly)
+            if (CheckReadOnly())
             {
                 base.KeyChar(keyChar);
                 return;
diff --git a/IDEHelper/Compiler/BfResolvedTypeUtils.cpp b/IDEHelper/Compiler/BfResolvedTypeUtils.cpp
index b8253306..c38c5c8f 100644
--- a/IDEHelper/Compiler/BfResolvedTypeUtils.cpp
+++ b/IDEHelper/Compiler/BfResolvedTypeUtils.cpp
@@ -1208,7 +1208,8 @@ void BfMethodInstance::GetIRFunctionInfo(BfModule* module, BfIRType& returnType,
 	{
 		returnType = module->mBfIRBuilder->MapType(mReturnType);
 	}	
-	
+
+	bool hasExplicitThis = false;
 	for (int paramIdx = -1; paramIdx < GetParamCount(); paramIdx++)
 	{
 		BfType* checkType = NULL;
@@ -1223,13 +1224,25 @@ void BfMethodInstance::GetIRFunctionInfo(BfModule* module, BfIRType& returnType,
 			else
 			{
 				if (HasExplicitThis())
+				{
 					checkType = GetParamType(0);
+
+					//TODO(BCF): Breaks tests
+					//hasExplicitThis = true;
+				}
 				else
 					checkType = GetOwner();				
 			}
 		}
 		else
 		{
+			if (hasExplicitThis)
+			{
+				// We already looked at this
+				hasExplicitThis = false;
+				continue;
+			}
+
 			checkType = GetParamType(paramIdx);
 		}