Delete the NodeType enum and other dead node members

NodeType was NRefactory's coarse node category, but only three reads remained
here: two checks now expressed as "is not Trivia" and one debug assert for the
pattern category. Remove the enum, the abstract property, every per-node
override, and the generator's emission, preserving the pattern-placeholder case
through an IPatternPlaceholder marker interface the output-visitor assert
checks. Also remove the unused PrimitiveExpression.AdvanceLocation helper.
Assisted-by: Claude:claude-opus-4-8:Claude Code

ICSharpCode.Decompiler.Generators/DecompilerSyntaxTreeGenerator.cs

@@ -174,8 +174,6 @@ internal class DecompilerSyntaxTreeGenerator : IIncrementalGenerator
 			builder.AppendLine($@"
 	sealed class Null{source.NodeName} : {source.NodeName}
 	{{
-		public override NodeType NodeType => NodeType.Unknown;
-
 		public override bool IsNull => true;
 
 		public override void AcceptVisitor(IAstVisitor visitor)
@@ -228,7 +226,7 @@ internal class DecompilerSyntaxTreeGenerator : IIncrementalGenerator
 		return pattern != null ? new PatternPlaceholder(pattern) : null{forgive};
 	}}
 
-	sealed class PatternPlaceholder : {source.NodeName}, INode
+	sealed class PatternPlaceholder : {source.NodeName}, INode, PatternMatching.IPatternPlaceholder
 	{{
 		readonly PatternMatching.Pattern child;
 
@@ -237,10 +235,6 @@ internal class DecompilerSyntaxTreeGenerator : IIncrementalGenerator
 			this.child = child;
 		}}
 
-		public override NodeType NodeType {{
-			get {{ return NodeType.Pattern; }}
-		}}
-
 		public override void AcceptVisitor(IAstVisitor visitor)
 		{{
 			visitor.VisitPatternPlaceholder(this, child);

ICSharpCode.Decompiler/CSharp/OutputVisitor/CSharpOutputVisitor.cs

@@ -73,7 +73,7 @@ namespace ICSharpCode.Decompiler.CSharp.OutputVisitor
 		{
 			// Ensure that nodes are visited in the proper nested order.
 			// Jumps to different subtrees are allowed only for the child of a placeholder node.
-			Debug.Assert(containerStack.Count == 0 || node.Parent == containerStack.Peek() || containerStack.Peek().NodeType == NodeType.Pattern);
+			Debug.Assert(containerStack.Count == 0 || node.Parent == containerStack.Peek() || containerStack.Peek() is IPatternPlaceholder);
 			containerStack.Push(node);
 			writer.StartNode(node);
 			foreach (var trivia in node.LeadingTrivia)

ICSharpCode.Decompiler/CSharp/OutputVisitor/InsertMissingTokensDecorator.cs

@@ -59,7 +59,7 @@ namespace ICSharpCode.Decompiler.CSharp.OutputVisitor
 		{
 			// ignore whitespace: these don't need to be processed.
 			// StartNode/EndNode is only called for them to support folding of comments.
-			if (node.NodeType != NodeType.Whitespace)
+			if (node is not Trivia)
 			{
 				currentList.Add(node);
 				nodes.Push(currentList);
@@ -81,7 +81,7 @@ namespace ICSharpCode.Decompiler.CSharp.OutputVisitor
 		{
 			// ignore whitespace: these don't need to be processed.
 			// StartNode/EndNode is only called for them to support folding of comments.
-			if (node.NodeType != NodeType.Whitespace)
+			if (node is not Trivia)
 			{
 				// A node that printed no tokens of its own collapses to a zero-width span here.
 				if (nodesAwaitingStart.Remove(node))

ICSharpCode.Decompiler/CSharp/Syntax/AstNode.cs

@@ -57,10 +57,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		const uint roleIndexMask = (1u << Role.RoleIndexBits) - 1;
 		protected const int AstNodeFlagsUsedBits = Role.RoleIndexBits;
 
-		public abstract NodeType NodeType {
-			get;
-		}
-
 		public virtual bool IsNull {
 			get {
 				return false;

ICSharpCode.Decompiler/CSharp/Syntax/AstType.cs

@@ -29,9 +29,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: true, hasPatternPlaceholder: true)]
 	public abstract partial class AstType : AstNode
 	{
-		public override NodeType NodeType {
-			get { return NodeType.TypeReference; }
-		}
 
 		public new AstType Clone()
 		{

ICSharpCode.Decompiler/CSharp/Syntax/ComposedType.cs

@@ -137,11 +137,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: false)]
 	public partial class ArraySpecifier : AstNode
 	{
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
 
 		public ArraySpecifier()
 		{

ICSharpCode.Decompiler/CSharp/Syntax/DocumentationReference.cs

@@ -75,10 +75,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			}
 		}
 
-		public override NodeType NodeType {
-			get { return NodeType.Unknown; }
-		}
-
 		/// <summary>
 		/// Gets/Sets the declaring type.
 		/// </summary>

ICSharpCode.Decompiler/CSharp/Syntax/Expressions/Expression.cs

@@ -30,11 +30,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: true, hasPatternPlaceholder: true)]
 	public abstract partial class Expression : AstNode
 	{
-		public override NodeType NodeType {
-			get {
-				return NodeType.Expression;
-			}
-		}
 
 		public new Expression Clone()
 		{

ICSharpCode.Decompiler/CSharp/Syntax/Expressions/InterpolatedStringExpression.cs

@@ -38,7 +38,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	{
 		public new static readonly Role<InterpolatedStringContent> Role = new Role<InterpolatedStringContent>("InterpolatedStringContent", Syntax.InterpolatedStringContent.Null);
 
-		public override NodeType NodeType => NodeType.Unknown;
 	}
 
 	/// <summary>

ICSharpCode.Decompiler/CSharp/Syntax/Expressions/PrimitiveExpression.cs

@@ -100,39 +100,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			this.format = format;
 		}
 
-		unsafe static TextLocation AdvanceLocation(TextLocation startLocation, string str)
-		{
-			int line = startLocation.Line;
-			int col = startLocation.Column;
-			fixed (char* start = str)
-			{
-				char* p = start;
-				char* endPtr = start + str.Length;
-				while (p < endPtr)
-				{
-					var nl = NewLine.GetDelimiterLength(*p, () => {
-						char* nextp = p + 1;
-						if (nextp < endPtr)
-							return *nextp;
-						return '\0';
-					});
-					if (nl > 0)
-					{
-						line++;
-						col = 1;
-						if (nl == 2)
-							p++;
-					}
-					else
-					{
-						col++;
-					}
-					p++;
-				}
-			}
-			return new TextLocation(line, col);
-		}
-
 		protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
 		{
 			PrimitiveExpression o = other as PrimitiveExpression;

ICSharpCode.Decompiler/CSharp/Syntax/Expressions/QueryExpression.cs

@@ -32,9 +32,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 
 	public abstract class QueryClause : AstNode
 	{
-		public override NodeType NodeType {
-			get { return NodeType.QueryClause; }
-		}
 	}
 
 	/// <summary>
@@ -229,10 +226,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		public readonly static TokenRole AscendingKeywordRole = new TokenRole("ascending");
 		public readonly static TokenRole DescendingKeywordRole = new TokenRole("descending");
 
-		public override NodeType NodeType {
-			get { return NodeType.Unknown; }
-		}
-
 		[Slot("Roles.Expression")]
 		public partial Expression Expression { get; set; }
 

ICSharpCode.Decompiler/CSharp/Syntax/Expressions/SwitchExpression.cs

@@ -50,6 +50,5 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		[Slot("BodyRole")]
 		public partial Expression Body { get; set; }
 
-		public override NodeType NodeType => NodeType.Unknown;
 	}
 }

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/Attribute.cs

@@ -34,11 +34,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: false)]
 	public partial class Attribute : AstNode
 	{
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
 
 		[Slot("Roles.Type")]
 		public partial AstType Type { get; set; }

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/AttributeSection.cs

@@ -32,11 +32,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: false, hasPatternPlaceholder: true)]
 	public partial class AttributeSection : AstNode
 	{
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
 
 		public string AttributeTarget {
 			get {

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/Comment.cs

@@ -56,11 +56,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: false)]
 	public partial class Comment : Trivia
 	{
-		public override NodeType NodeType {
-			get {
-				return NodeType.Whitespace;
-			}
-		}
 
 		CommentType commentType;
 

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/Constraint.cs

@@ -33,9 +33,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: true)]
 	public partial class Constraint : AstNode
 	{
-		public override NodeType NodeType {
-			get { return NodeType.Unknown; }
-		}
 
 		[Slot("Roles.ConstraintTypeParameter")]
 		public partial SimpleType TypeParameter { get; set; }

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/DelegateDeclaration.cs

@@ -34,9 +34,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: false)]
 	public partial class DelegateDeclaration : EntityDeclaration
 	{
-		public override NodeType NodeType {
-			get { return NodeType.TypeDeclaration; }
-		}
 
 		public override SymbolKind SymbolKind {
 			get { return SymbolKind.TypeDefinition; }

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/ExternAliasDeclaration.cs

@@ -32,11 +32,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: false)]
 	public partial class ExternAliasDeclaration : AstNode
 	{
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
 
 		public string Name {
 			get {

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/NamespaceDeclaration.cs

@@ -42,12 +42,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		public static readonly Role<AstNode> MemberRole = SyntaxTree.MemberRole;
 		public static readonly Role<AstType> NamespaceNameRole = new Role<AstType>("NamespaceName", AstType.Null);
 
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
-
 		public bool IsFileScoped { get; set; }
 
 		[Slot("NamespaceNameRole")]

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/PreProcessorDirective.cs

@@ -106,11 +106,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: false)]
 	public partial class PreProcessorDirective : Trivia
 	{
-		public override NodeType NodeType {
-			get {
-				return NodeType.Whitespace;
-			}
-		}
 
 		public PreProcessorDirectiveType Type {
 			get;

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/TypeDeclaration.cs

@@ -50,9 +50,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: false)]
 	public partial class TypeDeclaration : EntityDeclaration
 	{
-		public override NodeType NodeType {
-			get { return NodeType.TypeDeclaration; }
-		}
 
 		public override SymbolKind SymbolKind {
 			get { return SymbolKind.TypeDefinition; }

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/TypeParameterDeclaration.cs

@@ -33,10 +33,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		public static readonly TokenRole OutVarianceKeywordRole = new TokenRole("out");
 		public static readonly TokenRole InVarianceKeywordRole = new TokenRole("in");
 
-		public override NodeType NodeType {
-			get { return NodeType.Unknown; }
-		}
-
 		[Slot("AttributeRole")]
 		public partial AstNodeCollection<AttributeSection> Attributes { get; }
 

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/UsingAliasDeclaration.cs

@@ -36,12 +36,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		public static readonly Role<Identifier> AliasRole = new Role<Identifier>("Alias", Identifier.Null);
 		public static readonly Role<AstType> ImportRole = UsingDeclaration.ImportRole;
 
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
-
 		public string Alias {
 			get {
 				return AliasToken.Name;

ICSharpCode.Decompiler/CSharp/Syntax/GeneralScope/UsingDeclaration.cs

@@ -43,12 +43,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		public static readonly TokenRole UsingKeywordRole = new TokenRole("using");
 		public static readonly Role<AstType> ImportRole = new Role<AstType>("Import", AstType.Null);
 
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
-
 		[Slot("ImportRole")]
 		public partial AstType Import { get; set; }
 

ICSharpCode.Decompiler/CSharp/Syntax/Identifier.cs

@@ -40,11 +40,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: true)]
 	public partial class Identifier : AstNode
 	{
-		public override NodeType NodeType {
-			get {
-				return NodeType.Token;
-			}
-		}
 
 		string name;
 		public string Name {

ICSharpCode.Decompiler/CSharp/Syntax/NodeType.cs

@@ -1,54 +0,0 @@
-// 
-// NodeType.cs
-//  
-// Author:
-//       Mike Krüger <mkrueger@novell.com>
-// 
-// Copyright (c) 2009 Novell, Inc (http://www.novell.com)
-// 
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-// 
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-// 
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-namespace ICSharpCode.Decompiler.CSharp.Syntax
-{
-	public enum NodeType
-	{
-		Unknown,
-		/// <summary>
-		/// AstType
-		/// </summary>
-		TypeReference,
-		/// <summary>
-		/// Type or delegate declaration
-		/// </summary>
-		TypeDeclaration,
-		Member,
-		Statement,
-		Expression,
-		Token,
-		QueryClause,
-		/// <summary>
-		/// Comment or whitespace or pre-processor directive 
-		/// </summary>
-		Whitespace,
-		/// <summary>
-		/// Placeholder for a pattern
-		/// </summary>
-		Pattern
-	}
-}

ICSharpCode.Decompiler/CSharp/Syntax/PatternMatching/IPatternPlaceholder.cs

@@ -0,0 +1,28 @@
+// Copyright (c) 2011-2013 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+namespace ICSharpCode.Decompiler.CSharp.Syntax.PatternMatching
+{
+	/// <summary>
+	/// Marker for the generated node that wraps a <see cref="Pattern"/> so it can occupy an AST slot
+	/// (one per node type, each a sealed subclass of its own node, so they share no common node base).
+	/// </summary>
+	public interface IPatternPlaceholder
+	{
+	}
+}

ICSharpCode.Decompiler/CSharp/Syntax/Statements/Statement.cs

@@ -42,8 +42,5 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 			return (Statement)base.ReplaceWith(node => replaceFunction((Statement)node));
 		}
 
-		public override NodeType NodeType {
-			get { return NodeType.Statement; }
-		}
 	}
 }

ICSharpCode.Decompiler/CSharp/Syntax/Statements/SwitchStatement.cs

@@ -50,12 +50,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	{
 		public static readonly Role<CaseLabel> CaseLabelRole = new Role<CaseLabel>("CaseLabel", null);
 
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
-
 		[Slot("CaseLabelRole")]
 		public partial AstNodeCollection<CaseLabel> CaseLabels { get; }
 
@@ -72,12 +66,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		public static readonly TokenRole CaseKeywordRole = new TokenRole("case");
 		public static readonly TokenRole DefaultKeywordRole = new TokenRole("default");
 
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
-
 		/// <summary>
 		/// Gets or sets the expression. The expression can be null - if the expression is null, it's the default switch section.
 		/// </summary>

ICSharpCode.Decompiler/CSharp/Syntax/Statements/TryCatchStatement.cs

@@ -60,12 +60,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		public static readonly TokenRole CondLPar = new TokenRole("(");
 		public static readonly TokenRole CondRPar = new TokenRole(")");
 
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
-
 		[Slot("Roles.Type")]
 		public partial AstType Type { get; set; }
 

ICSharpCode.Decompiler/CSharp/Syntax/SyntaxTree.cs

@@ -38,12 +38,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	{
 		public static readonly Role<AstNode> MemberRole = new Role<AstNode>("Member", AstNode.Null);
 
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
-
 		[Slot("MemberRole")]
 		public partial AstNodeCollection<AstNode> Members { get; }
 

ICSharpCode.Decompiler/CSharp/Syntax/TupleAstType.cs

@@ -49,6 +49,5 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		[Slot("Roles.Identifier")]
 		public partial Identifier NameToken { get; set; }
 
-		public override NodeType NodeType => NodeType.Unknown;
 	}
 }

ICSharpCode.Decompiler/CSharp/Syntax/TypeMembers/Accessor.cs

@@ -46,9 +46,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: true)]
 	public partial class Accessor : EntityDeclaration
 	{
-		public override NodeType NodeType {
-			get { return NodeType.Unknown; }
-		}
 
 		public override SymbolKind SymbolKind {
 			get { return SymbolKind.Method; }

ICSharpCode.Decompiler/CSharp/Syntax/TypeMembers/ConstructorDeclaration.cs

@@ -74,12 +74,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		public static readonly TokenRole BaseKeywordRole = new TokenRole("base");
 		public static readonly TokenRole ThisKeywordRole = new TokenRole("this");
 
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
-
 		public ConstructorInitializerType ConstructorInitializerType {
 			get;
 			set;

ICSharpCode.Decompiler/CSharp/Syntax/TypeMembers/EntityDeclaration.cs

@@ -33,10 +33,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		public static readonly TokenRole ModifierRole = new TokenRole("modifier");
 		public static readonly Role<AstType> PrivateImplementationTypeRole = new Role<AstType>("PrivateImplementationType", AstType.Null);
 
-		public override NodeType NodeType {
-			get { return NodeType.Member; }
-		}
-
 		public abstract SymbolKind SymbolKind { get; }
 
 		public virtual AstNodeCollection<AttributeSection> Attributes {

ICSharpCode.Decompiler/CSharp/Syntax/TypeMembers/FixedVariableInitializer.cs

@@ -32,11 +32,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: false)]
 	public partial class FixedVariableInitializer : AstNode
 	{
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
 
 		public FixedVariableInitializer()
 		{

ICSharpCode.Decompiler/CSharp/Syntax/TypeMembers/ParameterDeclaration.cs

@@ -46,8 +46,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 		public static readonly TokenRole InModifierRole = new TokenRole("in");
 		public static readonly TokenRole ParamsModifierRole = new TokenRole("params");
 
-		public override NodeType NodeType => NodeType.Unknown;
-
 		[Slot("AttributeRole")]
 		public partial AstNodeCollection<AttributeSection> Attributes { get; }
 

ICSharpCode.Decompiler/CSharp/Syntax/TypeMembers/VariableInitializer.cs

@@ -32,11 +32,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: true, hasPatternPlaceholder: true)]
 	public partial class VariableInitializer : AstNode
 	{
-		public override NodeType NodeType {
-			get {
-				return NodeType.Unknown;
-			}
-		}
 
 		public VariableInitializer()
 		{

ICSharpCode.Decompiler/CSharp/Syntax/VariableDesignation.cs

@@ -21,7 +21,6 @@ namespace ICSharpCode.Decompiler.CSharp.Syntax
 	[DecompilerAstNode(hasNullNode: true)]
 	public abstract partial class VariableDesignation : AstNode
 	{
-		public override NodeType NodeType => NodeType.Unknown;
 	}
 
 	/// <summary>

ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj

@@ -251,13 +251,13 @@
     <Compile Include="CSharp\Syntax\PatternMatching\IdentifierExpressionBackreference.cs" />
     <Compile Include="CSharp\Syntax\MemberType.cs" />
     <Compile Include="CSharp\Syntax\Modifiers.cs" />
-    <Compile Include="CSharp\Syntax\NodeType.cs" />
     <Compile Include="CSharp\Syntax\PatternMatching\AnyNode.cs" />
     <Compile Include="CSharp\Syntax\PatternMatching\AnyNodeOrNull.cs" />
     <Compile Include="CSharp\Syntax\PatternMatching\Backreference.cs" />
     <Compile Include="CSharp\Syntax\PatternMatching\BacktrackingInfo.cs" />
     <Compile Include="CSharp\Syntax\PatternMatching\Choice.cs" />
     <Compile Include="CSharp\Syntax\PatternMatching\INode.cs" />
+    <Compile Include="CSharp\Syntax\PatternMatching\IPatternPlaceholder.cs" />
     <Compile Include="CSharp\Syntax\PatternMatching\Match.cs" />
     <Compile Include="CSharp\Syntax\PatternMatching\NamedNode.cs" />
     <Compile Include="CSharp\Syntax\PatternMatching\OptionalNode.cs" />