Make ExpressionNode (and derived) internal.

src/Avalonia.Base/Data/Core/AvaloniaPropertyAccessorNode.cs

@@ -3,7 +3,7 @@ using Avalonia.Reactive;
 
 namespace Avalonia.Data.Core
 {
-    public class AvaloniaPropertyAccessorNode : SettableNode
+    internal class AvaloniaPropertyAccessorNode : SettableNode
     {
         private IDisposable? _subscription;
         private readonly bool _enableValidation;

src/Avalonia.Base/Data/Core/EmptyExpressionNode.cs

@@ -1,6 +1,6 @@
 namespace Avalonia.Data.Core
 {
-    public class EmptyExpressionNode : ExpressionNode
+    internal class EmptyExpressionNode : ExpressionNode
     {
         public override string Description => ".";
     }

src/Avalonia.Base/Data/Core/ExpressionNode.cs

@@ -2,7 +2,7 @@ using System;
 
 namespace Avalonia.Data.Core
 {
-    public abstract class ExpressionNode
+    internal abstract class ExpressionNode
     {
         protected static readonly WeakReference<object?> UnsetReference = 
             new WeakReference<object?>(AvaloniaProperty.UnsetValue);

src/Avalonia.Base/Data/Core/IndexerNodeBase.cs

@@ -7,7 +7,7 @@ using Avalonia.Utilities;
 
 namespace Avalonia.Data.Core
 {
-    public abstract class IndexerNodeBase : SettableNode,
+    internal abstract class IndexerNodeBase : SettableNode,
         IWeakEventSubscriber<NotifyCollectionChangedEventArgs>,
         IWeakEventSubscriber<PropertyChangedEventArgs>
     {

src/Avalonia.Base/Data/Core/LogicalNotNode.cs

@@ -3,7 +3,7 @@ using System.Globalization;
 
 namespace Avalonia.Data.Core
 {
-    public class LogicalNotNode : ExpressionNode, ITransformNode
+    internal class LogicalNotNode : ExpressionNode, ITransformNode
     {
         public override string Description => "!";
 

src/Avalonia.Base/Data/Core/PropertyAccessorNode.cs

@@ -5,7 +5,7 @@ using Avalonia.Data.Core.Plugins;
 namespace Avalonia.Data.Core
 {
     [RequiresUnreferencedCode(TrimmingMessages.ExpressionNodeRequiresUnreferencedCodeMessage)]
-    public class PropertyAccessorNode : SettableNode
+    internal class PropertyAccessorNode : SettableNode
     {
         private readonly bool _enableValidation;
         private IPropertyAccessorPlugin? _customPlugin;

src/Avalonia.Base/Data/Core/SettableNode.cs

@@ -2,7 +2,7 @@
 
 namespace Avalonia.Data.Core
 {
-    public abstract class SettableNode : ExpressionNode
+    internal abstract class SettableNode : ExpressionNode
     {
         public bool SetTargetValue(object? value, BindingPriority priority)
         {

src/Avalonia.Base/Data/Core/StreamNode.cs

@@ -6,7 +6,7 @@ using Avalonia.Reactive;
 namespace Avalonia.Data.Core
 {
     [RequiresUnreferencedCode(TrimmingMessages.ExpressionNodeRequiresUnreferencedCodeMessage)]
-    public class StreamNode : ExpressionNode
+    internal class StreamNode : ExpressionNode
     {
         private IStreamPlugin? _customPlugin = null;
         private IDisposable? _subscription;

src/Avalonia.Base/Data/Core/TypeCastNode.cs

@@ -4,7 +4,7 @@ using System.Text;
 
 namespace Avalonia.Data.Core
 {
-    public class TypeCastNode : ExpressionNode
+    internal class TypeCastNode : ExpressionNode
     {
         public override string Description => $"as {TargetType.FullName}";
 

src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/CompiledBindings/CompiledBindingPath.cs

@@ -24,7 +24,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
         }
 
         [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = TrimmingMessages.CompiledBindingSafeSupressWarningMessage)]
-        public ExpressionNode BuildExpression(bool enableValidation)
+        internal ExpressionNode BuildExpression(bool enableValidation)
         {
             ExpressionNode pathRoot = null;
             ExpressionNode path = null;

src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/CompiledBindings/StrongTypeCastNode.cs

@@ -3,7 +3,7 @@ using Avalonia.Data.Core;
 
 namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
 {
-    public class StrongTypeCastNode : TypeCastNode
+    internal class StrongTypeCastNode : TypeCastNode
     {
         private Func<object, object> _cast;
 

src/Markup/Avalonia.Markup/Markup/Parsers/Nodes/ElementNameNode.cs

@@ -6,7 +6,7 @@ using Avalonia.Reactive;
 
 namespace Avalonia.Markup.Parsers.Nodes
 {
-    public class ElementNameNode : ExpressionNode
+    internal class ElementNameNode : ExpressionNode
     {
         private readonly WeakReference<INameScope> _nameScope;
         private readonly string _name;

src/Markup/Avalonia.Markup/Markup/Parsers/Nodes/FindAncestorNode.cs

@@ -5,7 +5,7 @@ using Avalonia.Reactive;
 
 namespace Avalonia.Markup.Parsers.Nodes
 {
-    public class FindAncestorNode : ExpressionNode
+    internal class FindAncestorNode : ExpressionNode
     {
         private readonly int _level;
         private readonly Type? _ancestorType;

src/Markup/Avalonia.Markup/Markup/Parsers/Nodes/SelfNode.cs

@@ -2,7 +2,7 @@
 
 namespace Avalonia.Markup.Parsers.Nodes
 {
-    public class SelfNode : ExpressionNode
+    internal class SelfNode : ExpressionNode
     {
         public override string Description => "$self";
     }