DomNode: enforce tree invariants, fix bug in InsertChildBefore, and add Remove/Replace methods.

ICSharpCode.NRefactory/CSharp/Dom/DomNode.cs

@@ -1,6 +1,6 @@
-// 
+// 
 // AstNode.cs
-//  
+//
 // Author:
 //       Mike Krüger <mkrueger@novell.com>
 // 
@@ -26,13 +26,15 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 
 namespace ICSharpCode.NRefactory.CSharp
 {
 	public abstract class DomNode
 	{
+		#region Null
 		public static readonly DomNode Null = new NullAstNode ();
-		class NullAstNode : DomNode
+		sealed class NullAstNode : DomNode
 		{
 			public override NodeType NodeType {
 				get {
@@ -51,6 +53,14 @@ namespace ICSharpCode.NRefactory.CSharp
 				return default (S);
 			}
 		}
+		#endregion
+		
+		DomNode parent;
+		DomNode prevSibling;
+		DomNode nextSibling;
+		DomNode firstChild;
+		DomNode lastChild;
+		int role;
 		
 		public abstract NodeType NodeType {
 			get;
@@ -63,8 +73,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public virtual DomLocation StartLocation {
-			get { 
+			get {
-				var child = FirstChild;
+				var child = firstChild;
 				if (child == null)
 					return DomLocation.Empty;
 				return child.StartLocation;
@@ -72,8 +82,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public virtual DomLocation EndLocation {
-			get { 
+			get {
-				var child = LastChild;
+				var child = lastChild;
 				if (child == null)
 					return DomLocation.Empty;
 				return child.EndLocation;
@@ -81,107 +91,166 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public DomNode Parent {
-			get;
+			get { return parent; }
-			set;
 		}
 		
 		public int Role {
-			get;
+			get { return role; }
-			set;
 		}
 		
 		public DomNode NextSibling {
-			get;
+			get { return nextSibling; }
-			set;
 		}
 		
 		public DomNode PrevSibling {
-			get;
+			get { return prevSibling; }
-			set;
 		}
 		
 		public DomNode FirstChild {
-			get;
+			get { return firstChild; }
-			set;
 		}
 		
 		public DomNode LastChild {
-			get;
+			get { return lastChild; }
-			set;
 		}
 		
 		public IEnumerable<DomNode> Children {
 			get {
-				var cur = FirstChild;
+				var cur = firstChild;
 				while (cur != null) {
 					yield return cur;
-					cur = cur.NextSibling;
+					cur = cur.nextSibling;
 				}
 			}
 		}
 		
 		public DomNode GetChildByRole (int role)
 		{
-			var cur = FirstChild;
+			var cur = firstChild;
 			while (cur != null) {
-				if (cur.Role == role)
+				if (cur.role == role)
 					return cur;
-				cur = cur.NextSibling;
+				cur = cur.nextSibling;
 			}
 			return null;
 		}
 		
 		public IEnumerable<DomNode> GetChildrenByRole (int role)
 		{
-			var cur = FirstChild;
+			var cur = firstChild;
 			while (cur != null) {
-				if (cur.Role == role)
+				if (cur.role == role)
 					yield return cur;
-				cur = cur.NextSibling;
+				cur = cur.nextSibling;
 			}
 		}
 		
-		public void AddChild (DomNode child)
+		public void AddChild (DomNode child, int role)
 		{
 			if (child == null)
 				return;
-			child.Parent = this;
+			if (child.parent != null)
-			if (FirstChild == null) {
+				throw new ArgumentException ("Node is already used in another tree.", "child");
-				LastChild = FirstChild = child;
+			child.parent = this;
+			child.role = role;
+			if (firstChild == null) {
+				lastChild = firstChild = child;
 			} else {
-				LastChild.NextSibling = child;
+				lastChild.nextSibling = child;
-				child.PrevSibling = LastChild;
+				child.prevSibling = lastChild;
-				LastChild = child;
+				lastChild = child;
 			}
 		}
 		
-		public void AddChild (DomNode child, int role)
+		public void InsertChildBefore (DomNode nextSibling, DomNode child, int role)
 		{
+			if (nextSibling == null) {
+				AddChild (child, role);
+				return;
+			}
+			
 			if (child == null)
 				return;
-			child.Role = role;
+			if (child.parent != null)
-			AddChild (child);
+				throw new ArgumentException ("Node is already used in another tree.", "child");
+			if (nextSibling.parent != this)
+				throw new ArgumentException ("NextSibling is not a child of this node.", "nextSibling");
+			
+			child.parent = this;
+			child.role = role;
+			child.nextSibling = nextSibling;
+			child.prevSibling = nextSibling.prevSibling;
+			
+			if (nextSibling.prevSibling != null) {
+				Debug.Assert(nextSibling.prevSibling.nextSibling == nextSibling);
+				nextSibling.prevSibling.nextSibling = child;
+			} else {
+				Debug.Assert(firstChild == nextSibling);
+				firstChild = child;
+			}
+			nextSibling.prevSibling = child;
 		}
 		
-		public void InsertChildBefore (DomNode nextSibling, DomNode child, int role)
+		/// <summary>
+		/// Removes this node from its parent.
+		/// </summary>
+		public void Remove()
 		{
-			if (child == null)
+			if (parent != null) {
-				return;
+				if (prevSibling != null) {
-			
+					Debug.Assert(prevSibling.nextSibling == this);
-			if (FirstChild == null || nextSibling == null) {
+					prevSibling.nextSibling = nextSibling;
-				AddChild (child, role);
+				} else {
+					Debug.Assert(parent.firstChild == this);
+					parent.firstChild = nextSibling;
+				}
+				if (nextSibling != null) {
+					Debug.Assert(nextSibling.prevSibling == this);
+					nextSibling.prevSibling = prevSibling;
+				} else {
+					Debug.Assert(parent.lastChild == this);
+					parent.lastChild = prevSibling;
+				}
+				parent = null;
+				prevSibling = null;
+				nextSibling = null;
+			}
+		}
+		
+		/// <summary>
+		/// Replaces this node with the new node.
+		/// </summary>
+		public void Replace(DomNode newNode)
+		{
+			if (newNode == null) {
+				Remove();
 				return;
 			}
-			child.Parent = this;
+			if (newNode.parent != null)
-			child.Role = role;
+				throw new ArgumentException ("Node is already used in another tree.", "newNode");
-			
+			newNode.parent = parent;
-			child.NextSibling = nextSibling;
+			newNode.role = role;
-			
+			newNode.prevSibling = prevSibling;
-			if (nextSibling.PrevSibling != null) {
+			newNode.nextSibling = nextSibling;
-				child.PrevSibling = nextSibling.PrevSibling;
+			if (parent != null) {
-				nextSibling.PrevSibling.NextSibling = child;
+				if (prevSibling != null) {
+					Debug.Assert(prevSibling.nextSibling == this);
+					prevSibling.nextSibling = newNode;
+				} else {
+					Debug.Assert(parent.firstChild == this);
+					parent.firstChild = newNode;
+				}
+				if (nextSibling != null) {
+					Debug.Assert(nextSibling.prevSibling == this);
+					nextSibling.prevSibling = newNode;
+				} else {
+					Debug.Assert(parent.lastChild == this);
+					parent.lastChild = newNode;
+				}
+				parent = null;
+				prevSibling = null;
+				nextSibling = null;
 			}
-			nextSibling.PrevSibling = child;
 		}
 		
 		public abstract S AcceptVisitor<T, S> (DomVisitor<T, S> visitor, T data);
@@ -205,7 +274,7 @@ namespace ICSharpCode.NRefactory.CSharp
 			public const int TargetExpression = 14;
 			public const int Member = 15;
 			
-			// some pre defined constants for most used punctuation 
+			// some pre defined constants for most used punctuation
 			
 			public const int LPar = 50; // (
 			public const int RPar = 51; // )

ICSharpCode.NRefactory/CSharp/Parser/CSharpParser.cs

@@ -260,7 +260,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				if (namespaceStack.Count > 0) {
 					namespaceStack.Peek ().AddChild (child, NamespaceDeclaration.Roles.Member);
 				} else {
-					unit.AddChild (child);
+					unit.AddChild (child, CompilationUnit.Roles.Member);
 				}	
 			}
 			
@@ -2224,7 +2224,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				
 				NewAnonymousType aType = l.Expr as NewAnonymousType;
 				AnonymousTypeParameter param = ((AnonymousTypeParameter)aType.Parameters[1]);
-				result.AddChild (new Identifier (param.Name, Convert (param.Location)));
+				result.AddChild (new Identifier (param.Name, Convert (param.Location)), Identifier.Roles.Identifier);
 				
 				if (location != null)
 					result.AddChild (new CSharpTokenNode (Convert (location[1]), 1), QueryExpressionWhereClause.Roles.Assign);
@@ -2250,7 +2250,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				if (location != null)
 					result.AddChild (new CSharpTokenNode (Convert (location[0]), "join".Length), QueryExpressionJoinClause.JoinKeywordRole);
 				
-				result.AddChild (new Identifier (join.JoinVariable.Name, Convert (join.JoinVariable.Location)));
+				result.AddChild (new Identifier (join.JoinVariable.Name, Convert (join.JoinVariable.Location)), Identifier.Roles.Identifier);
 				
 				if (location != null)
 					result.AddChild (new CSharpTokenNode (Convert (location[1]), "in".Length), QueryExpressionJoinClause.InKeywordRole);
@@ -2275,7 +2275,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				if (location != null)
 					result.AddChild (new CSharpTokenNode (Convert (location[0]), "join".Length), QueryExpressionJoinClause.JoinKeywordRole);
 				
-				result.AddChild (new Identifier (groupJoin.JoinVariable.Name, Convert (groupJoin.JoinVariable.Location)));
+				result.AddChild (new Identifier (groupJoin.JoinVariable.Name, Convert (groupJoin.JoinVariable.Location)), Identifier.Roles.Identifier);
 				
 				if (location != null)
 					result.AddChild (new CSharpTokenNode (Convert (location[1]), "in".Length), QueryExpressionJoinClause.InKeywordRole);
@@ -2293,7 +2293,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				if (location != null)
 					result.AddChild (new CSharpTokenNode (Convert (location[4]), "into".Length), QueryExpressionJoinClause.IntoKeywordRole);
 				
-				result.AddChild (new Identifier (groupJoin.JoinVariable.Name, Convert (groupJoin.JoinVariable.Location)));
+				result.AddChild (new Identifier (groupJoin.JoinVariable.Name, Convert (groupJoin.JoinVariable.Location)), Identifier.Roles.Identifier);
 				return result;
 			}
 			
@@ -2352,7 +2352,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		void InsertComment (DomNode node, Comment comment)
 		{
 			if (node.EndLocation < comment.StartLocation) {
-				node.AddChild (comment);
+				node.AddChild (comment, DomNode.Roles.Comment);
 				return;
 			}
 			
@@ -2367,7 +2367,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				}
 			}
 			
-			node.AddChild (comment);
+			node.AddChild (comment, DomNode.Roles.Comment);
 		}
 		
 		void InsertComments (CompilerCompilationUnit top, ConversionVisitor conversionVisitor)