Merge NRefactory '180a690f373354796520d9468138d95f193f8156' to ILSpy.

NRefactory/ICSharpCode.NRefactory.CSharp.AstVerifier/.gitignore

@@ -0,0 +1,3 @@
+
+bin/
+obj/

NRefactory/ICSharpCode.NRefactory.CSharp.AstVerifier/AssemblyInfo.cs

@@ -0,0 +1,27 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+
+// Information about this assembly is defined by the following attributes. 
+// Change them to the values specific to your project.
+
+[assembly: AssemblyTitle("ICSharpCode.NRefactory.CSharp.AstVerifier")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("")]
+[assembly: AssemblyCopyright("mike")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// The assembly version has the format "{Major}.{Minor}.{Build}.{Revision}".
+// The form "{Major}.{Minor}.*" will automatically update the build and revision,
+// and "{Major}.{Minor}.{Build}.*" will update just the revision.
+
+[assembly: AssemblyVersion("1.0.*")]
+
+// The following attributes are used to specify the signing key for the assembly, 
+// if desired. See the Mono documentation for more information about signing.
+
+//[assembly: AssemblyDelaySign(false)]
+//[assembly: AssemblyKeyFile("")]
+

NRefactory/ICSharpCode.NRefactory.CSharp.AstVerifier/ICSharpCode.NRefactory.CSharp.AstVerifier.csproj

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>10.0.0</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{961DADFA-7CE6-429F-BC22-47630D6DB826}</ProjectGuid>
+    <OutputType>Exe</OutputType>
+    <RootNamespace>ICSharpCode.NRefactory.CSharp.AstVerifier</RootNamespace>
+    <AssemblyName>AstVerifier</AssemblyName>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug</OutputPath>
+    <DefineConstants>DEBUG;</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <Externalconsole>true</Externalconsole>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>none</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Release</OutputPath>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <Externalconsole>true</Externalconsole>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Main.cs" />
+    <Compile Include="AssemblyInfo.cs" />
+  </ItemGroup>
+  <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
+  <ItemGroup>
+    <ProjectReference Include="..\ICSharpCode.NRefactory.CSharp\ICSharpCode.NRefactory.CSharp.csproj">
+      <Project>{53DCA265-3C3C-42F9-B647-F72BA678122B}</Project>
+      <Name>ICSharpCode.NRefactory.CSharp</Name>
+    </ProjectReference>
+    <ProjectReference Include="..\ICSharpCode.NRefactory\ICSharpCode.NRefactory.csproj">
+      <Project>{3B2A5653-EC97-4001-BB9B-D90F1AF2C371}</Project>
+      <Name>ICSharpCode.NRefactory</Name>
+    </ProjectReference>
+  </ItemGroup>
+</Project>

NRefactory/ICSharpCode.NRefactory.CSharp.AstVerifier/Main.cs

@@ -0,0 +1,83 @@
+using System;
+using System.IO;
+
+namespace ICSharpCode.NRefactory.CSharp.AstVerifier
+{
+	class MainClass
+	{
+		static bool IsMatch (string src1, string src2, out int i, out int j)
+		{
+			i = 0;
+			j = 0;
+			while (i < src1.Length && j < src2.Length) {
+				char c1 = src1 [i];
+				char c2 = src2 [j];
+				if (char.IsWhiteSpace (c1)) {
+					i++;
+					continue;
+				}
+				if (char.IsWhiteSpace (c2)) {
+					j++;
+					continue;
+				}
+				if (c1 != c2)
+					return false;
+				i++;
+				j++;
+			}
+			while (i < src1.Length && char.IsWhiteSpace (src1[i])) {
+				i++;
+			}
+			while (j < src2.Length && char.IsWhiteSpace (src2[j])) {
+				j++;
+			}
+
+			return i == src1.Length && j == src2.Length;
+		}
+
+		public static void Main (string[] args)
+		{
+			if (args.Length == 0) {
+				Console.WriteLine ("Usage: AstVerifier [-v|-verbose] [Directory]");
+				return;
+			}
+			string directory = args[args.Length - 1];
+			bool verboseOutput =  args.Length > 1 && (args[0] == "-v" || args[0] == "-verbose");
+
+			try {
+				if (!Directory.Exists (directory)) {
+					Console.WriteLine ("Directory not found.");
+					return;
+				}
+			} catch (IOException) {
+				Console.WriteLine ("Exception while trying to access the directory.");
+				return;
+			}
+			int failed = 0, passed = 0;
+			Console.WriteLine ("search in " + directory);
+			foreach (var file in Directory.GetFileSystemEntries (directory, "*", SearchOption.AllDirectories)) {
+				if (!file.EndsWith (".cs"))
+					continue;
+				string text = File.ReadAllText (file);
+				var unit = CompilationUnit.Parse (text, file);
+				if (unit == null)
+					continue;
+				string generated = unit.GetText ();
+				int i, j;
+				if (!IsMatch (text, generated, out i, out j)) {
+					if (i > 0 && j > 0 && verboseOutput) {
+						Console.WriteLine ("fail :" + file + "----original:");
+						Console.WriteLine (text.Substring (0, Math.Min (text.Length, i + 1)));
+						Console.WriteLine ("----generated:");
+						Console.WriteLine (generated.Substring (0, Math.Min (generated.Length, j + 1)));
+					}
+					failed++;
+				} else {
+					passed++;
+				}
+			}
+
+			Console.WriteLine ("{0} passed, {1} failed", passed, failed);
+		}
+	}
+}

NRefactory/ICSharpCode.NRefactory.CSharp/Analysis/ControlFlow.cs

@@ -1,4 +1,4 @@
-// Copyright (c) AlphaSierraPapa for the SharpDevelop Team
+// Copyright (c) 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
@@ -113,7 +113,7 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 		/// Gets the try-finally statements that this control flow edge is leaving.
 		/// </summary>
 		public IEnumerable<TryCatchStatement> TryFinallyStatements {
-			get { return jumpOutOfTryFinally ?? EmptyList<TryCatchStatement>.Instance; }
+			get { return jumpOutOfTryFinally ?? Enumerable.Empty<TryCatchStatement>(); }
 		}
 	}
 	
@@ -420,7 +420,8 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 					falseEnd = ifElseStatement.FalseStatement.AcceptVisitor(this, falseBegin);
 				}
 				ControlFlowNode end = builder.CreateEndNode(ifElseStatement);
-				Connect(trueEnd, end);
+				if (trueEnd != null)
+					Connect(trueEnd, end);
 				if (falseEnd != null) {
 					Connect(falseEnd, end);
 				} else if (cond != true) {

NRefactory/ICSharpCode.NRefactory.CSharp/Analysis/DefiniteAssignmentAnalysis.cs

@@ -304,54 +304,53 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 				return DefiniteAssignmentStatus.PotentiallyAssigned;
 		}
 		
-		void ChangeNodeStatus(DefiniteAssignmentNode node, DefiniteAssignmentStatus inputStatus)
+		void ChangeNodeStatus (DefiniteAssignmentNode node, DefiniteAssignmentStatus inputStatus)
 		{
 			if (node.NodeStatus == inputStatus)
 				return;
 			node.NodeStatus = inputStatus;
 			DefiniteAssignmentStatus outputStatus;
 			switch (node.Type) {
-				case ControlFlowNodeType.StartNode:
-				case ControlFlowNodeType.BetweenStatements:
-					if (node.NextStatement is IfElseStatement) {
-						// Handle if-else as a condition node
+			case ControlFlowNodeType.StartNode:
+			case ControlFlowNodeType.BetweenStatements:
+				if (node.NextStatement is IfElseStatement) {
+					// Handle if-else as a condition node
 						goto case ControlFlowNodeType.LoopCondition;
-					}
-					if (inputStatus == DefiniteAssignmentStatus.DefinitelyAssigned) {
-						// There isn't any way to un-assign variables, so we don't have to check the expression
-						// if the status already is definitely assigned.
-						outputStatus = DefiniteAssignmentStatus.DefinitelyAssigned;
-					} else {
-						outputStatus = CleanSpecialValues(node.NextStatement.AcceptVisitor(visitor, inputStatus));
-					}
-					break;
-				case ControlFlowNodeType.EndNode:
-					outputStatus = inputStatus;
-					if (node.PreviousStatement.Role == TryCatchStatement.FinallyBlockRole
-					    && (outputStatus == DefiniteAssignmentStatus.DefinitelyAssigned || outputStatus == DefiniteAssignmentStatus.PotentiallyAssigned))
-					{
-						TryCatchStatement tryFinally = (TryCatchStatement)node.PreviousStatement.Parent;
-						// Changing the status on a finally block potentially changes the status of all edges leaving that finally block:
-						foreach (ControlFlowEdge edge in allNodes.SelectMany(n => n.Outgoing)) {
-							if (edge.IsLeavingTryFinally && edge.TryFinallyStatements.Contains(tryFinally)) {
-								DefiniteAssignmentStatus s = edgeStatus[edge];
-								if (s == DefiniteAssignmentStatus.PotentiallyAssigned) {
-									ChangeEdgeStatus(edge, outputStatus);
-								}
+				}
+				if (inputStatus == DefiniteAssignmentStatus.DefinitelyAssigned) {
+					// There isn't any way to un-assign variables, so we don't have to check the expression
+					// if the status already is definitely assigned.
+					outputStatus = DefiniteAssignmentStatus.DefinitelyAssigned;
+				} else {
+					outputStatus = CleanSpecialValues (node.NextStatement.AcceptVisitor (visitor, inputStatus));
+				}
+				break;
+			case ControlFlowNodeType.EndNode:
+				outputStatus = inputStatus;
+				if (node.PreviousStatement.Role == TryCatchStatement.FinallyBlockRole
+					&& (outputStatus == DefiniteAssignmentStatus.DefinitelyAssigned || outputStatus == DefiniteAssignmentStatus.PotentiallyAssigned)) {
+					TryCatchStatement tryFinally = (TryCatchStatement)node.PreviousStatement.Parent;
+					// Changing the status on a finally block potentially changes the status of all edges leaving that finally block:
+					foreach (ControlFlowEdge edge in allNodes.SelectMany(n => n.Outgoing)) {
+						if (edge.IsLeavingTryFinally && edge.TryFinallyStatements.Contains (tryFinally)) {
+							DefiniteAssignmentStatus s = edgeStatus [edge];
+							if (s == DefiniteAssignmentStatus.PotentiallyAssigned) {
+								ChangeEdgeStatus (edge, outputStatus);
 							}
 						}
 					}
+				}
+				break;
+			case ControlFlowNodeType.LoopCondition:
+				ForeachStatement foreachStmt = node.NextStatement as ForeachStatement;
+				if (foreachStmt != null) {
+					outputStatus = CleanSpecialValues (foreachStmt.InExpression.AcceptVisitor (visitor, inputStatus));
+					if (foreachStmt.VariableName == this.variableName)
+						outputStatus = DefiniteAssignmentStatus.DefinitelyAssigned;
 					break;
-				case ControlFlowNodeType.LoopCondition:
-					ForeachStatement foreachStmt = node.NextStatement as ForeachStatement;
-					if (foreachStmt != null) {
-						outputStatus = CleanSpecialValues(foreachStmt.InExpression.AcceptVisitor(visitor, inputStatus));
-						if (foreachStmt.VariableName == this.variableName)
-							outputStatus = DefiniteAssignmentStatus.DefinitelyAssigned;
-						break;
-					} else {
-						Debug.Assert(node.NextStatement is IfElseStatement || node.NextStatement is WhileStatement || node.NextStatement is ForStatement || node.NextStatement is DoWhileStatement);
-						Expression condition = node.NextStatement.GetChildByRole(AstNode.Roles.Condition);
+				} else {
+					Debug.Assert (node.NextStatement is IfElseStatement || node.NextStatement is WhileStatement || node.NextStatement is ForStatement || node.NextStatement is DoWhileStatement);
+					Expression condition = node.NextStatement.GetChildByRole (Roles.Condition);
 						if (condition.IsNull)
 							outputStatus = inputStatus;
 						else

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/AstNode.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // AstNode.cs
 //
 // Author:
@@ -33,8 +33,11 @@ using System.Threading;
 
 namespace ICSharpCode.NRefactory.CSharp
 {
-	public abstract class AstNode : AbstractAnnotatable, PatternMatching.INode
+	public abstract class AstNode : AbstractAnnotatable, ICSharpCode.NRefactory.TypeSystem.IFreezable, PatternMatching.INode
 	{
+		// the Root role must be available when creating the null nodes, so we can't put it in the Roles class
+		internal static readonly Role<AstNode> RootRole = new Role<AstNode> ("Root");
+		
 		#region Null
 		public static readonly AstNode Null = new NullAstNode ();
 		
@@ -52,7 +55,16 @@ namespace ICSharpCode.NRefactory.CSharp
 				}
 			}
 			
-			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+			}
+			
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return default (T);
+			}
+			
+			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 			{
 				return default (S);
 			}
@@ -83,7 +95,17 @@ namespace ICSharpCode.NRefactory.CSharp
 				get { return NodeType.Pattern; }
 			}
 			
-			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+				visitor.VisitPatternPlaceholder (this, child);
+			}
+			
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return visitor.VisitPatternPlaceholder (this, child);
+			}
+
+			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 			{
 				return visitor.VisitPatternPlaceholder (this, child, data);
 			}
@@ -105,7 +127,42 @@ namespace ICSharpCode.NRefactory.CSharp
 		AstNode nextSibling;
 		AstNode firstChild;
 		AstNode lastChild;
-		Role role = RootRole;
+		
+		// Flags, from least significant to most significant bits:
+		// - Role.RoleIndexBits: role index
+		// - 1 bit: IsFrozen
+		protected uint flags = RootRole.Index;
+		// Derived classes may also use a few bits,
+		// for example Identifier uses 1 bit for IsVerbatim
+		
+		const uint roleIndexMask = (1u << Role.RoleIndexBits) - 1;
+		const uint frozenBit = 1u << Role.RoleIndexBits;
+		protected const int AstNodeFlagsUsedBits = Role.RoleIndexBits + 1;
+		
+		protected AstNode()
+		{
+			if (IsNull)
+				Freeze();
+		}
+		
+		public bool IsFrozen {
+			get { return (flags & frozenBit) != 0; }
+		}
+		
+		public void Freeze()
+		{
+			if (!IsFrozen) {
+				for (AstNode child = firstChild; child != null; child = child.nextSibling)
+					child.Freeze();
+				flags |= frozenBit;
+			}
+		}
+		
+		protected void ThrowIfFrozen()
+		{
+			if (IsFrozen)
+				throw new InvalidOperationException("Cannot mutate frozen " + GetType().Name);
+		}
 		
 		public abstract NodeType NodeType {
 			get;
@@ -135,22 +192,6 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		/// <summary>
-		/// Returns true, if the given coordinates are in the node.
-		/// </summary>
-		public bool IsInside (TextLocation location)
-		{
-			return StartLocation <= location && location <= EndLocation;
-		}
-		
-		/// <summary>
-		/// Returns true, if the given coordinates (line, column) are in the node.
-		/// </summary>
-		public bool IsInside(int line, int column)
-		{
-			return IsInside(new TextLocation (line, column));
-		}
-		
 		/// <summary>
 		/// Gets the region from StartLocation to EndLocation for this node.
 		/// The file name of the region is set based on the parent CompilationUnit's file name.
@@ -168,7 +209,22 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public Role Role {
-			get { return role; }
+			get {
+				return Role.GetByIndex(flags & roleIndexMask);
+			}
+			set {
+				if (value == null)
+					throw new ArgumentNullException("value");
+				if (!value.IsValid(this))
+					throw new ArgumentException("This node is not valid in the new role.");
+				ThrowIfFrozen();
+				SetRole(value);
+			}
+		}
+		
+		void SetRole(Role role)
+		{
+			flags = (flags & ~roleIndexMask) | role.Index;
 		}
 		
 		public AstNode NextSibling {
@@ -187,6 +243,12 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return lastChild; }
 		}
 		
+		public bool HasChildren {
+			get {
+				return firstChild != null;
+			}
+		}
+		
 		public IEnumerable<AstNode> Children {
 			get {
 				AstNode next;
@@ -211,6 +273,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
+		/// <summary>
+		/// Gets the ancestors of this node (including this node itself)
+		/// </summary>
+		public IEnumerable<AstNode> AncestorsAndSelf {
+			get {
+				for (AstNode cur = this; cur != null; cur = cur.parent) {
+					yield return cur;
+				}
+			}
+		}
+		
 		/// <summary>
 		/// Gets all descendants of this node (excluding this node itself).
 		/// </summary>
@@ -233,17 +306,23 @@ namespace ICSharpCode.NRefactory.CSharp
 		/// Gets the first child with the specified role.
 		/// Returns the role's null object if the child is not found.
 		/// </summary>
-		public T GetChildByRole<T> (Role<T> role) where T : AstNode
+		public T GetChildByRole<T>(Role<T> role) where T : AstNode
 		{
 			if (role == null)
 				throw new ArgumentNullException ("role");
+			uint roleIndex = role.Index;
 			for (var cur = firstChild; cur != null; cur = cur.nextSibling) {
-				if (cur.role == role)
+				if ((cur.flags & roleIndexMask) == roleIndex)
 					return (T)cur;
 			}
 			return role.NullObject;
 		}
 		
+		public T GetParent<T>() where T : AstNode
+		{
+			return Ancestors.OfType<T>().FirstOrDefault();
+		}
+				
 		public AstNodeCollection<T> GetChildrenByRole<T> (Role<T> role) where T : AstNode
 		{
 			return new AstNodeCollection<T> (this, role);
@@ -264,10 +343,11 @@ namespace ICSharpCode.NRefactory.CSharp
 				throw new ArgumentNullException ("role");
 			if (child == null || child.IsNull)
 				return;
-			if (this.IsNull)
-				throw new InvalidOperationException ("Cannot add children to null nodes");
+			ThrowIfFrozen();
 			if (child.parent != null)
 				throw new ArgumentException ("Node is already used in another tree.", "child");
+			if (child.IsFrozen)
+				throw new ArgumentException ("Cannot add a frozen node.", "child");
 			AddChildUnsafe (child, role);
 		}
 		
@@ -277,7 +357,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		void AddChildUnsafe (AstNode child, Role role)
 		{
 			child.parent = this;
-			child.role = role;
+			child.SetRole(role);
 			if (firstChild == null) {
 				lastChild = firstChild = child;
 			} else {
@@ -286,6 +366,13 @@ namespace ICSharpCode.NRefactory.CSharp
 				lastChild = child;
 			}
 		}
+
+		public void InsertChildsBefore<T>(AstNode nextSibling, Role<T> role, params T[] child) where T : AstNode
+		{
+			foreach (var cur in child) {
+				InsertChildBefore(nextSibling, cur, role);
+			}
+		}
 		
 		public void InsertChildBefore<T> (AstNode nextSibling, T child, Role<T> role) where T : AstNode
 		{
@@ -298,8 +385,11 @@ namespace ICSharpCode.NRefactory.CSharp
 			
 			if (child == null || child.IsNull)
 				return;
+			ThrowIfFrozen();
 			if (child.parent != null)
 				throw new ArgumentException ("Node is already used in another tree.", "child");
+			if (child.IsFrozen)
+				throw new ArgumentException ("Cannot add a frozen node.", "child");
 			if (nextSibling.parent != this)
 				throw new ArgumentException ("NextSibling is not a child of this node.", "nextSibling");
 			// No need to test for "Cannot add children to null nodes",
@@ -310,7 +400,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		void InsertChildBeforeUnsafe (AstNode nextSibling, AstNode child, Role role)
 		{
 			child.parent = this;
-			child.role = role;
+			child.SetRole(role);
 			child.nextSibling = nextSibling;
 			child.prevSibling = nextSibling.prevSibling;
 			
@@ -335,6 +425,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		public void Remove ()
 		{
 			if (parent != null) {
+				ThrowIfFrozen();
 				if (prevSibling != null) {
 					Debug.Assert (prevSibling.nextSibling == this);
 					prevSibling.nextSibling = nextSibling;
@@ -350,7 +441,6 @@ namespace ICSharpCode.NRefactory.CSharp
 					parent.lastChild = prevSibling;
 				}
 				parent = null;
-				role = Roles.Root;
 				prevSibling = null;
 				nextSibling = null;
 			}
@@ -370,10 +460,11 @@ namespace ICSharpCode.NRefactory.CSharp
 			if (parent == null) {
 				throw new InvalidOperationException (this.IsNull ? "Cannot replace the null nodes" : "Cannot replace the root node");
 			}
+			ThrowIfFrozen();
 			// Because this method doesn't statically check the new node's type with the role,
 			// we perform a runtime test:
-			if (!role.IsValid (newNode)) {
-				throw new ArgumentException (string.Format ("The new node '{0}' is not valid in the role {1}", newNode.GetType ().Name, role.ToString ()), "newNode");
+			if (!this.Role.IsValid (newNode)) {
+				throw new ArgumentException (string.Format ("The new node '{0}' is not valid in the role {1}", newNode.GetType ().Name, this.Role.ToString ()), "newNode");
 			}
 			if (newNode.parent != null) {
 				// newNode is used within this tree?
@@ -385,9 +476,11 @@ namespace ICSharpCode.NRefactory.CSharp
 					throw new ArgumentException ("Node is already used in another tree.", "newNode");
 				}
 			}
+			if (newNode.IsFrozen)
+				throw new ArgumentException ("Cannot add a frozen node.", "newNode");
 			
 			newNode.parent = parent;
-			newNode.role = role;
+			newNode.SetRole(this.Role);
 			newNode.prevSibling = prevSibling;
 			newNode.nextSibling = nextSibling;
 			if (parent != null) {
@@ -408,7 +501,6 @@ namespace ICSharpCode.NRefactory.CSharp
 				parent = null;
 				prevSibling = null;
 				nextSibling = null;
-				role = Roles.Root;
 			}
 		}
 		
@@ -421,7 +513,7 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 			AstNode oldParent = parent;
 			AstNode oldSuccessor = nextSibling;
-			Role oldRole = role;
+			Role oldRole = this.Role;
 			Remove ();
 			AstNode replacement = replaceFunction (this);
 			if (oldSuccessor != null && oldSuccessor.parent != oldParent)
@@ -450,26 +542,28 @@ namespace ICSharpCode.NRefactory.CSharp
 			AstNode copy = (AstNode)MemberwiseClone ();
 			// First, reset the shallow pointer copies
 			copy.parent = null;
-			copy.role = Roles.Root;
 			copy.firstChild = null;
 			copy.lastChild = null;
 			copy.prevSibling = null;
 			copy.nextSibling = null;
+			copy.flags &= ~frozenBit; // unfreeze the copy
 			
 			// Then perform a deep copy:
 			for (AstNode cur = firstChild; cur != null; cur = cur.nextSibling) {
-				copy.AddChildUnsafe (cur.Clone (), cur.role);
+				copy.AddChildUnsafe (cur.Clone (), cur.Role);
 			}
 			
 			// Finally, clone the annotation, if necessary
-			ICloneable copiedAnnotations = copy.annotations as ICloneable; // read from copy (for thread-safety)
-			if (copiedAnnotations != null)
-				copy.annotations = copiedAnnotations.Clone();
+			copy.CloneAnnotations();
 			
 			return copy;
 		}
 		
-		public abstract S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T));
+		public abstract void AcceptVisitor (IAstVisitor visitor);
+		
+		public abstract T AcceptVisitor<T> (IAstVisitor<T> visitor);
+		
+		public abstract S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data);
 		
 		#region Pattern Matching
 		protected static bool MatchString (string pattern, string text)
@@ -519,7 +613,6 @@ namespace ICSharpCode.NRefactory.CSharp
 				return Parent.GetPrevNode ();
 			return null;
 		}
-		
 		// filters all non c# nodes (comments, white spaces or pre processor directives)
 		public AstNode GetCSharpNodeBefore (AstNode node)
 		{
@@ -532,11 +625,22 @@ namespace ICSharpCode.NRefactory.CSharp
 			return null;
 		}
 		
+		#region GetNodeAt
+		/// <summary>
+		/// Gets the node specified by T at the location line, column. This is useful for getting a specific node from the tree. For example searching
+		/// the current method declaration.
+		/// (End exclusive)
+		/// </summary>
 		public AstNode GetNodeAt (int line, int column, Predicate<AstNode> pred = null)
 		{
 			return GetNodeAt (new TextLocation (line, column), pred);
 		}
 		
+		/// <summary>
+		/// Gets the node specified by pred at location. This is useful for getting a specific node from the tree. For example searching
+		/// the current method declaration.
+		/// (End exclusive)
+		/// </summary>
 		public AstNode GetNodeAt (TextLocation location, Predicate<AstNode> pred = null)
 		{
 			AstNode result = null;
@@ -559,6 +663,11 @@ namespace ICSharpCode.NRefactory.CSharp
 			return result;
 		}
 		
+		/// <summary>
+		/// Gets the node specified by T at the location line, column. This is useful for getting a specific node from the tree. For example searching
+		/// the current method declaration.
+		/// (End exclusive)
+		/// </summary>
 		public T GetNodeAt<T> (int line, int column) where T : AstNode
 		{
 			return GetNodeAt<T> (new TextLocation (line, column));
@@ -567,6 +676,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		/// <summary>
 		/// Gets the node specified by T at location. This is useful for getting a specific node from the tree. For example searching
 		/// the current method declaration.
+		/// (End exclusive)
 		/// </summary>
 		public T GetNodeAt<T> (TextLocation location) where T : AstNode
 		{
@@ -589,6 +699,97 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 			return result;
 		}
+
+		#endregion
+
+		#region GetAdjacentNodeAt
+		/// <summary>
+		/// Gets the node specified by pred at the location line, column. This is useful for getting a specific node from the tree. For example searching
+		/// the current method declaration.
+		/// (End inclusive)
+		/// </summary>
+		public AstNode GetAdjacentNodeAt(int line, int column, Predicate<AstNode> pred = null)
+		{
+			return GetAdjacentNodeAt (new TextLocation (line, column), pred);
+		}
+		
+		/// <summary>
+		/// Gets the node specified by pred at location. This is useful for getting a specific node from the tree. For example searching
+		/// the current method declaration.
+		/// (End inclusive)
+		/// </summary>
+		public AstNode GetAdjacentNodeAt (TextLocation location, Predicate<AstNode> pred = null)
+		{
+			AstNode result = null;
+			AstNode node = this;
+			while (node.FirstChild != null) {
+				var child = node.FirstChild;
+				while (child != null) {
+					if (child.StartLocation <= location && location <= child.EndLocation) {
+						if (pred == null || pred (child))
+							result = child;
+						node = child;
+						break;
+					}
+					child = child.NextSibling;
+				}
+				// found no better child node - therefore the parent is the right one.
+				if (child == null)
+					break;
+			}
+			return result;
+		}
+		
+		/// <summary>
+		/// Gets the node specified by T at the location line, column. This is useful for getting a specific node from the tree. For example searching
+		/// the current method declaration.
+		/// (End inclusive)
+		/// </summary>
+		public T GetAdjacentNodeAt<T>(int line, int column) where T : AstNode
+		{
+			return GetAdjacentNodeAt<T> (new TextLocation (line, column));
+		}
+		
+		/// <summary>
+		/// Gets the node specified by T at location. This is useful for getting a specific node from the tree. For example searching
+		/// the current method declaration.
+		/// (End inclusive)
+		/// </summary>
+		public T GetAdjacentNodeAt<T> (TextLocation location) where T : AstNode
+		{
+			T result = null;
+			AstNode node = this;
+			while (node.FirstChild != null) {
+				var child = node.FirstChild;
+				while (child != null) {
+					if (child.StartLocation <= location && location < child.EndLocation) {
+						if (child is T)
+							result = (T)child;
+						node = child;
+						break;
+					}
+					child = child.NextSibling;
+				}
+				// found no better child node - therefore the parent is the right one.
+				if (child == null)
+					break;
+			}
+			return result;
+		}
+		#endregion
+
+
+		/// <summary>
+		/// Gets the node that fully contains the range from startLocation to endLocation.
+		/// </summary>
+		public AstNode GetNodeContaining(TextLocation startLocation, TextLocation endLocation)
+		{
+			for (AstNode child = firstChild; child != null; child = child.nextSibling) {
+				if (child.StartLocation <= startLocation && endLocation <= child.EndLocation)
+					return child.GetNodeContaining(startLocation, endLocation);
+			}
+			return this;
+		}
 		
 		public IEnumerable<AstNode> GetNodesBetween (int startLine, int startColumn, int endLine, int endColumn)
 		{
@@ -619,16 +820,65 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
+		/// <summary>
+		/// Gets the node as formatted C# output.
+		/// </summary>
+		/// <param name='formattingOptions'>
+		/// Formatting options.
+		/// </param>
+		public virtual string GetText (CSharpFormattingOptions formattingOptions = null)
+		{
+			if (IsNull)
+				return "";
+			var w = new StringWriter ();
+			AcceptVisitor (new CSharpOutputVisitor (w, formattingOptions ?? FormattingOptionsFactory.CreateMono ()));
+			return w.ToString ();
+		}
+		
+		/// <summary>
+		/// Returns true, if the given coordinates (line, column) are in the node.
+		/// </summary>
+		/// <returns>
+		/// True, if the given coordinates are between StartLocation and EndLocation (exclusive); otherwise, false.
+		/// </returns>
 		public bool Contains (int line, int column)
 		{
 			return Contains (new TextLocation (line, column));
 		}
-
+		
+		/// <summary>
+		/// Returns true, if the given coordinates are in the node.
+		/// </summary>
+		/// <returns>
+		/// True, if location is between StartLocation and EndLocation (exclusive); otherwise, false.
+		/// </returns>
 		public bool Contains (TextLocation location)
 		{
 			return this.StartLocation <= location && location < this.EndLocation;
 		}
 		
+		/// <summary>
+		/// Returns true, if the given coordinates (line, column) are in the node.
+		/// </summary>
+		/// <returns>
+		/// True, if the given coordinates are between StartLocation and EndLocation (inclusive); otherwise, false.
+		/// </returns>
+		public bool IsInside (int line, int column)
+		{
+			return IsInside (new TextLocation (line, column));
+		}
+		
+		/// <summary>
+		/// Returns true, if the given coordinates are in the node.
+		/// </summary>
+		/// <returns>
+		/// True, if location is between StartLocation and EndLocation (inclusive); otherwise, false.
+		/// </returns>
+		public bool IsInside (TextLocation location)
+		{
+			return this.StartLocation <= location && location <= this.EndLocation;
+		}
+		
 		public override void AddAnnotation (object annotation)
 		{
 			if (this.IsNull)
@@ -640,60 +890,12 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 			if (IsNull)
 				return "Null";
-			StringWriter w = new StringWriter();
-			AcceptVisitor(new CSharpOutputVisitor(w, new CSharpFormattingOptions()), null);
-			string text = w.ToString().TrimEnd().Replace("\t", "").Replace(w.NewLine, " ");
+			string text = GetText();
+			text = text.TrimEnd().Replace("\t", "").Replace(Environment.NewLine, " ");
 			if (text.Length > 100)
 				return text.Substring(0, 97) + "...";
 			else
 				return text;
 		}
-		
-		// the Root role must be available when creating the null nodes, so we can't put it in the Roles class
-		static readonly Role<AstNode> RootRole = new Role<AstNode> ("Root");
-		
-		public static class Roles
-		{
-			/// <summary>
-			/// Root of an abstract syntax tree.
-			/// </summary>
-			public static readonly Role<AstNode> Root = RootRole;
-			
-			// some pre defined constants for common roles
-			public static readonly Role<Identifier> Identifier = new Role<Identifier> ("Identifier", CSharp.Identifier.Null);
-			public static readonly Role<BlockStatement> Body = new Role<BlockStatement> ("Body", CSharp.BlockStatement.Null);
-			public static readonly Role<ParameterDeclaration> Parameter = new Role<ParameterDeclaration> ("Parameter");
-			public static readonly Role<Expression> Argument = new Role<Expression> ("Argument", CSharp.Expression.Null);
-			public static readonly Role<AstType> Type = new Role<AstType> ("Type", CSharp.AstType.Null);
-			public static readonly Role<Expression> Expression = new Role<Expression> ("Expression", CSharp.Expression.Null);
-			public static readonly Role<Expression> TargetExpression = new Role<Expression> ("Target", CSharp.Expression.Null);
-			public readonly static Role<Expression> Condition = new Role<Expression> ("Condition", CSharp.Expression.Null);
-			public static readonly Role<TypeParameterDeclaration> TypeParameter = new Role<TypeParameterDeclaration> ("TypeParameter");
-			public static readonly Role<AstType> TypeArgument = new Role<AstType> ("TypeArgument", CSharp.AstType.Null);
-			public readonly static Role<Constraint> Constraint = new Role<Constraint> ("Constraint");
-			public static readonly Role<VariableInitializer> Variable = new Role<VariableInitializer> ("Variable");
-			public static readonly Role<Statement> EmbeddedStatement = new Role<Statement> ("EmbeddedStatement", CSharp.Statement.Null);
-			public static readonly Role<CSharpTokenNode> Keyword = new Role<CSharpTokenNode> ("Keyword", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> InKeyword = new Role<CSharpTokenNode> ("InKeyword", CSharpTokenNode.Null);
-			
-			// some pre defined constants for most used punctuation
-			public static readonly Role<CSharpTokenNode> LPar = new Role<CSharpTokenNode> ("LPar", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> RPar = new Role<CSharpTokenNode> ("RPar", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> LBracket = new Role<CSharpTokenNode> ("LBracket", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> RBracket = new Role<CSharpTokenNode> ("RBracket", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> LBrace = new Role<CSharpTokenNode> ("LBrace", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> RBrace = new Role<CSharpTokenNode> ("RBrace", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> LChevron = new Role<CSharpTokenNode> ("LChevron", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> RChevron = new Role<CSharpTokenNode> ("RChevron", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> Comma = new Role<CSharpTokenNode> ("Comma", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> Dot = new Role<CSharpTokenNode> ("Dot", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> Semicolon = new Role<CSharpTokenNode> ("Semicolon", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> Assign = new Role<CSharpTokenNode> ("Assign", CSharpTokenNode.Null);
-			public static readonly Role<CSharpTokenNode> Colon = new Role<CSharpTokenNode> ("Colon", CSharpTokenNode.Null);
-			public static readonly Role<Comment> Comment = new Role<Comment> ("Comment");
-			public static readonly Role<PreProcessorDirective> PreProcessorDirective = new Role<PreProcessorDirective> ("PreProcessorDirective");
-			public static readonly Role<ErrorNode> Error = new Role<ErrorNode> ("Error");
-			
-		}
 	}
 }

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/AstType.cs

@@ -39,7 +39,16 @@ namespace ICSharpCode.NRefactory.CSharp
 				}
 			}
 			
-			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+			}
+			
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return default (T);
+			}
+			
+			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 			{
 				return default (S);
 			}
@@ -75,9 +84,19 @@ namespace ICSharpCode.NRefactory.CSharp
 				get { return NodeType.Pattern; }
 			}
 			
-			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+				visitor.VisitPatternPlaceholder (this, child);
+			}
+			
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return visitor.VisitPatternPlaceholder (this, child);
+			}
+			
+			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 			{
-				return visitor.VisitPatternPlaceholder(this, child, data);
+				return visitor.VisitPatternPlaceholder (this, child, data);
 			}
 			
 			public override ITypeReference ToTypeReference(SimpleNameLookupMode lookupMode)
@@ -153,6 +172,26 @@ namespace ICSharpCode.NRefactory.CSharp
 			return new TypeReferenceExpression { Type = this }.Member(memberName);
 		}
 		
+		/// <summary>
+		/// Builds an expression that can be used to access a static member on this type.
+		/// </summary>
+		public MemberType MemberType(string memberName, params AstType[] typeArguments)
+		{
+			var memberType = new MemberType(this, memberName);
+			memberType.TypeArguments.AddRange(typeArguments);
+			return memberType;
+		}
+		
+		/// <summary>
+		/// Builds an expression that can be used to access a static member on this type.
+		/// </summary>
+		public MemberType MemberType(string memberName, IEnumerable<AstType> typeArguments)
+		{
+			var memberType = new MemberType(this, memberName);
+			memberType.TypeArguments.AddRange(typeArguments);
+			return memberType;
+		}
+		
 		/// <summary>
 		/// Builds an invocation expression using this type as target.
 		/// </summary>

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/CSharpModifierToken.cs

@@ -29,19 +29,29 @@ using System.Linq;
 
 namespace ICSharpCode.NRefactory.CSharp
 {
-	
 	public class CSharpModifierToken : CSharpTokenNode
 	{
 		Modifiers modifier;
 		
 		public Modifiers Modifier {
 			get { return modifier; }
-			set {
-				this.tokenLength = GetModifierName(value).Length;
-				this.modifier = value;
+			set { 
+				ThrowIfFrozen();
+				this.modifier = value; 
 			}
 		}
 		
+		protected override int TokenLength {
+			get {
+				return GetModifierName (modifier).Length;
+			}
+		}
+		
+		public override string GetText (CSharpFormattingOptions formattingOptions = null)
+		{
+			return GetModifierName (Modifier);
+		}
+		
 		protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
 		{
 			CSharpModifierToken o = other as CSharpModifierToken;
@@ -65,7 +75,7 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return allModifiers; }
 		}
 		
-		public CSharpModifierToken (TextLocation location, Modifiers modifier) : base (location, 0)
+		public CSharpModifierToken (TextLocation location, Modifiers modifier) : base (location)
 		{
 			this.Modifier = modifier;
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/CSharpTokenNode.cs

@@ -27,7 +27,13 @@ using System;
 
 namespace ICSharpCode.NRefactory.CSharp
 {
-	public class CSharpTokenNode : AstNode, IRelocatable
+	/// <summary>
+	/// Represents a token in C#. Note that the type of the token is defined through the TokenRole.
+	/// </summary>
+	/// <remarks>
+	/// In all non null c# token nodes the Role of a CSharpToken must be a TokenRole.
+	/// </remarks>
+	public class CSharpTokenNode : AstNode
 	{
 		public static new readonly CSharpTokenNode Null = new NullCSharpTokenNode ();
 		class NullCSharpTokenNode : CSharpTokenNode
@@ -38,11 +44,20 @@ namespace ICSharpCode.NRefactory.CSharp
 				}
 			}
 			
-			public NullCSharpTokenNode () : base (TextLocation.Empty, 0)
+			public NullCSharpTokenNode () : base (TextLocation.Empty)
 			{
 			}
 			
-			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return default (T);
+			}
+			
+			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 			{
 				return default (S);
 			}
@@ -53,7 +68,6 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		
 		public override NodeType NodeType {
 			get {
 				return NodeType.Token;
@@ -67,27 +81,43 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		protected int tokenLength;
+		protected virtual int TokenLength {
+			get {
+				if (!(Role is TokenRole))
+					return 0;
+				return ((TokenRole)Role).Length;
+			}
+		}
+		
 		public override TextLocation EndLocation {
 			get {
-				return new TextLocation (StartLocation.Line, StartLocation.Column + tokenLength);
+				return new TextLocation (StartLocation.Line, StartLocation.Column + TokenLength);
 			}
 		}
 		
-		public CSharpTokenNode (TextLocation location, int tokenLength)
+		public CSharpTokenNode (TextLocation location)
 		{
 			this.startLocation = location;
-			this.tokenLength = tokenLength;
 		}
 		
-		#region IRelocationable implementation
-		void IRelocatable.SetStartLocation (TextLocation startLocation)
+		public override string GetText (CSharpFormattingOptions formattingOptions = null)
+		{
+			if (!(Role is TokenRole))
+				return null;
+			return ((TokenRole)Role).Token;
+		}
+
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitCSharpTokenNode (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
 		{
-			this.startLocation = startLocation;
+			return visitor.VisitCSharpTokenNode (this);
 		}
-		#endregion
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitCSharpTokenNode (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/CSharpUtil.cs

@@ -74,7 +74,6 @@ namespace ICSharpCode.NRefactory.CSharp
 					return new UnaryOperatorExpression (UnaryOperatorType.Not, new ParenthesizedExpression (condition));
 				}
 			}
-			
 			if (condition is ConditionalExpression) {
 				var cEx = condition as ConditionalExpression;
 				cEx.Condition = InvertCondition (cEx.Condition);
@@ -83,8 +82,7 @@ namespace ICSharpCode.NRefactory.CSharp
 			if (condition is PrimitiveExpression) {
 				var pex = condition as PrimitiveExpression;
 				if (pex.Value is bool) {
-					pex.Value = !((bool)pex.Value);
-					return pex; 
+					return new PrimitiveExpression (!((bool)pex.Value)); 
 				}
 			}
 			

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/CompilationUnit.cs

@@ -28,6 +28,10 @@ using System.Collections.Generic;
 using ICSharpCode.NRefactory.CSharp.Resolver;
 using ICSharpCode.NRefactory.CSharp.TypeSystem;
 using ICSharpCode.NRefactory.TypeSystem;
+using System.Threading;
+using Mono.CSharp;
+using System.IO;
+using ICSharpCode.NRefactory.Editor;
 
 namespace ICSharpCode.NRefactory.CSharp
 {
@@ -41,10 +45,22 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
+		string fileName;
+		
 		/// <summary>
 		/// Gets/Sets the file name of this compilation unit.
 		/// </summary>
-		public string FileName { get; set; }
+		public string FileName {
+			get { return fileName; }
+			set {
+				ThrowIfFrozen();
+				fileName = value;
+			}
+		}
+		
+		public AstNodeCollection<AstNode> Members {
+			get { return GetChildrenByRole(MemberRole); }
+		}
 		
 		List<Error> errors = new List<Error> ();
 		
@@ -68,17 +84,18 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 		}
 		
-		public IEnumerable<TypeDeclaration> GetTypes (bool includeInnerTypes = false)
+		public IEnumerable<TypeDeclaration> GetTypes(bool includeInnerTypes = false)
 		{
 			Stack<AstNode> nodeStack = new Stack<AstNode> ();
-			nodeStack.Push (this);
+			nodeStack.Push(this);
 			while (nodeStack.Count > 0) {
-				var curNode = nodeStack.Pop ();
-				if (curNode is TypeDeclaration)
+				var curNode = nodeStack.Pop();
+				if (curNode is TypeDeclaration) {
 					yield return (TypeDeclaration)curNode;
+				}
 				foreach (var child in curNode.Children) {
 					if (!(child is Statement || child is Expression) &&
-					    (child.Role != TypeDeclaration.MemberRole || (child is TypeDeclaration && includeInnerTypes)))
+					    (child.Role != Roles.TypeMemberRole || (child is TypeDeclaration && includeInnerTypes)))
 						nodeStack.Push (child);
 				}
 			}
@@ -90,7 +107,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			return o != null && GetChildrenByRole(MemberRole).DoMatch(o.GetChildrenByRole(MemberRole), match);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitCompilationUnit (this);
+		}
+		
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitCompilationUnit (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitCompilationUnit (this, data);
 		}
@@ -98,14 +125,45 @@ namespace ICSharpCode.NRefactory.CSharp
 		/// <summary>
 		/// Converts this compilation unit into a parsed file that can be stored in the type system.
 		/// </summary>
-		public CSharpParsedFile ToTypeSystem()
+		public CSharpParsedFile ToTypeSystem ()
 		{
-			if (string.IsNullOrEmpty(this.FileName))
-				throw new InvalidOperationException("Cannot use ToTypeSystem() on a compilation unit without file name.");
-			var v = new TypeSystemConvertVisitor(this.FileName);
-			v.VisitCompilationUnit(this, null);
+			if (string.IsNullOrEmpty (this.FileName))
+				throw new InvalidOperationException ("Cannot use ToTypeSystem() on a compilation unit without file name.");
+			var v = new TypeSystemConvertVisitor (this.FileName);
+			v.VisitCompilationUnit (this);
 			return v.ParsedFile;
 		}
+		
+		public static CompilationUnit Parse (string text, string fileName = "", CompilerSettings settings = null, CancellationToken cancellationToken = default (CancellationToken))
+		{
+			var parser = new CSharpParser ();
+			if (settings != null)
+				parser.CompilerSettings = settings;
+			return parser.Parse (text, fileName);
+		}
+		
+		public static CompilationUnit Parse (TextReader reader, string fileName = "", CompilerSettings settings = null, CancellationToken cancellationToken = default (CancellationToken))
+		{
+			var parser = new CSharpParser ();
+			if (settings != null)
+				parser.CompilerSettings = settings;
+			return parser.Parse (reader, fileName, 0);
+		}
+		
+		public static CompilationUnit Parse (Stream stream, string fileName = "", CompilerSettings settings = null, CancellationToken cancellationToken = default (CancellationToken))
+		{
+			var parser = new CSharpParser ();
+			if (settings != null)
+				parser.CompilerSettings = settings;
+			return parser.Parse (stream, fileName, 0);
+		}
+		
+		public static CompilationUnit Parse (ITextSource textSource, string fileName = "", CompilerSettings settings = null, CancellationToken cancellationToken = default (CancellationToken))
+		{
+			var parser = new CSharpParser ();
+			if (settings != null)
+				parser.CompilerSettings = settings;
+			return parser.Parse (textSource, fileName, 0);
+		}
 	}
 }
-

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/ComposedType.cs

@@ -33,8 +33,8 @@ namespace ICSharpCode.NRefactory.CSharp
 {
 	public class ComposedType : AstType
 	{
-		public static readonly Role<CSharpTokenNode> NullableRole = new Role<CSharpTokenNode>("Nullable", CSharpTokenNode.Null);
-		public static readonly Role<CSharpTokenNode> PointerRole = new Role<CSharpTokenNode>("Pointer", CSharpTokenNode.Null);
+		public static readonly TokenRole NullableRole = new TokenRole("?");
+		public static readonly TokenRole PointerRole = new TokenRole("*");
 		public static readonly Role<ArraySpecifier> ArraySpecifierRole = new Role<ArraySpecifier>("ArraySpecifier");
 		
 		public AstType BaseType {
@@ -47,7 +47,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return !GetChildByRole(NullableRole).IsNull;
 			}
 			set {
-				SetChildByRole(NullableRole, value ? new CSharpTokenNode(TextLocation.Empty, 1) : null);
+				SetChildByRole(NullableRole, value ? new CSharpTokenNode(TextLocation.Empty) : null);
 			}
 		}
 		
@@ -64,7 +64,7 @@ namespace ICSharpCode.NRefactory.CSharp
 					d--;
 				}
 				while (d < value) {
-					InsertChildBefore(GetChildByRole(PointerRole), new CSharpTokenNode(TextLocation.Empty, 1), PointerRole);
+					InsertChildBefore(GetChildByRole(PointerRole), new CSharpTokenNode(TextLocation.Empty), PointerRole);
 					d++;
 				}
 			}
@@ -74,7 +74,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildrenByRole (ArraySpecifierRole); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitComposedType (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitComposedType (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitComposedType (this, data);
 		}
@@ -166,7 +176,7 @@ namespace ICSharpCode.NRefactory.CSharp
 					d--;
 				}
 				while (d < value) {
-					InsertChildBefore(GetChildByRole(Roles.Comma), new CSharpTokenNode(TextLocation.Empty, 1), Roles.Comma);
+					InsertChildBefore(GetChildByRole(Roles.Comma), new CSharpTokenNode(TextLocation.Empty), Roles.Comma);
 					d++;
 				}
 			}
@@ -176,7 +186,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.RBracket); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitArraySpecifier (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitArraySpecifier (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitArraySpecifier(this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/DocumentationReference.cs

@@ -0,0 +1,149 @@
+// Copyright (c) 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.
+
+using System;
+using ICSharpCode.NRefactory.TypeSystem;
+
+namespace ICSharpCode.NRefactory.CSharp
+{
+	/// <summary>
+	/// Represents a 'cref' reference in XML documentation.
+	/// </summary>
+	public class DocumentationReference : AstNode
+	{
+		public static readonly Role<AstType> DeclaringTypeRole = new Role<AstType>("DeclaringType", AstType.Null);
+		public static readonly Role<AstType> ConversionOperatorReturnTypeRole = new Role<AstType>("ConversionOperatorReturnType", AstType.Null);
+		
+		EntityType entityType;
+		OperatorType operatorType;
+		bool hasParameterList;
+		
+		/// <summary>
+		/// Gets/Sets the entity type.
+		/// Possible values are:
+		///   <c>EntityType.Operator</c> for operators,
+		///   <c>EntityType.Indexer</c> for indexers,
+		///   <c>EntityType.TypeDefinition</c> for references to primitive types,
+		///   and <c>EntityType.None</c> for everything else.
+		/// </summary>
+		public EntityType EntityType {
+			get { return entityType; }
+			set {
+				ThrowIfFrozen();
+				entityType = value;
+			}
+		}
+		
+		/// <summary>
+		/// Gets/Sets the operator type.
+		/// This property is only used when EntityType==Operator.
+		/// </summary>
+		public OperatorType OperatorType {
+			get { return operatorType; }
+			set {
+				ThrowIfFrozen();
+				operatorType = value;
+			}
+		}
+		
+		/// <summary>
+		/// Gets/Sets whether a parameter list was provided.
+		/// </summary>
+		public bool HasParameterList {
+			get { return hasParameterList; }
+			set {
+				ThrowIfFrozen();
+				hasParameterList = value;
+			}
+		}
+		
+		public override NodeType NodeType {
+			get { return NodeType.Unknown; }
+		}
+		
+		/// <summary>
+		/// Gets/Sets the declaring type.
+		/// </summary>
+		public AstType DeclaringType {
+			get { return GetChildByRole(DeclaringTypeRole); }
+			set { SetChildByRole(DeclaringTypeRole, value); }
+		}
+		
+		/// <summary>
+		/// Gets/sets the member name.
+		/// This property is only used when EntityType==None.
+		/// </summary>
+		public string MemberName {
+			get { return GetChildByRole(Roles.Identifier).Name; }
+			set { SetChildByRole(Roles.Identifier, Identifier.Create(value)); }
+		}
+		
+		/// <summary>
+		/// Gets/Sets the return type of conversion operators.
+		/// This property is only used when EntityType==Operator and OperatorType is explicit or implicit.
+		/// </summary>
+		public AstType ConversionOperatorReturnType {
+			get { return GetChildByRole(ConversionOperatorReturnTypeRole); }
+			set { SetChildByRole(ConversionOperatorReturnTypeRole, value); }
+		}
+		
+		public AstNodeCollection<AstType> TypeArguments {
+			get { return GetChildrenByRole (Roles.TypeArgument); }
+		}
+		
+		public AstNodeCollection<ParameterDeclaration> Parameters {
+			get { return GetChildrenByRole (Roles.Parameter); }
+		}
+		
+		protected internal override bool DoMatch(AstNode other, ICSharpCode.NRefactory.PatternMatching.Match match)
+		{
+			DocumentationReference o = other as DocumentationReference;
+			if (!(o != null && this.EntityType == o.EntityType && this.HasParameterList == o.HasParameterList))
+				return false;
+			if (this.EntityType == EntityType.Operator) {
+				if (this.OperatorType != o.OperatorType)
+					return false;
+				if (this.OperatorType == OperatorType.Implicit || this.OperatorType == OperatorType.Explicit) {
+					if (!this.ConversionOperatorReturnType.DoMatch(o.ConversionOperatorReturnType, match))
+						return false;
+				}
+			} else if (this.EntityType == EntityType.None) {
+				if (!MatchString(this.MemberName, o.MemberName))
+					return false;
+				if (!this.TypeArguments.DoMatch(o.TypeArguments, match))
+					return false;
+			}
+			return this.Parameters.DoMatch(o.Parameters, match);
+		}
+		
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitDocumentationReference (this);
+		}
+		
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitDocumentationReference (this);
+		}
+		
+		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
+		{
+			return visitor.VisitDocumentationReference (this, data);
+		}
+	}
+}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/ErrorNode.cs

@@ -58,7 +58,16 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return default (T);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			// nothing
 			return default (S);

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/AnonymousMethodExpression.cs

@@ -34,17 +34,26 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class AnonymousMethodExpression : Expression
 	{
-		public readonly static Role<CSharpTokenNode> AsyncModifierRole = LambdaExpression.AsyncModifierRole;
+		public readonly static TokenRole DelegateKeywordRole = new TokenRole ("delegate");
+		public readonly static TokenRole AsyncModifierRole = LambdaExpression.AsyncModifierRole;
 		
-		public bool IsAsync { get; set; }
+		bool isAsync;
+		
+		public bool IsAsync {
+			get { return isAsync; }
+			set { ThrowIfFrozen(); isAsync = value; }
+		}
 		
 		// used to tell the difference between delegate {} and delegate () {}
+		bool hasParameterList;
+		
 		public bool HasParameterList {
-			get; set;
+			get { return hasParameterList; }
+			set { ThrowIfFrozen(); hasParameterList = value; }
 		}
 		
 		public CSharpTokenNode DelegateToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (DelegateKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -82,7 +91,17 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitAnonymousMethodExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitAnonymousMethodExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitAnonymousMethodExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/AnonymousTypeCreateExpression.cs

@@ -33,8 +33,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class AnonymousTypeCreateExpression : Expression
 	{
+		public readonly static TokenRole NewKeywordRole = new TokenRole ("new");
+		
 		public CSharpTokenNode NewToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (NewKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -64,7 +66,17 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitAnonymousTypeCreateExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitAnonymousTypeCreateExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitAnonymousTypeCreateExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/ArrayCreateExpression.cs

@@ -26,9 +26,14 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class ArrayCreateExpression : Expression
 	{
+		public readonly static TokenRole NewKeywordRole = new TokenRole ("new");
 		public readonly static Role<ArraySpecifier> AdditionalArraySpecifierRole = new Role<ArraySpecifier>("AdditionalArraySpecifier");
 		public readonly static Role<ArrayInitializerExpression> InitializerRole = new Role<ArrayInitializerExpression>("Initializer", ArrayInitializerExpression.Null);
 		
+		public CSharpTokenNode NewToken {
+			get { return GetChildByRole (NewKeywordRole); }
+		}
+		
 		public AstType Type {
 			get { return GetChildByRole (Roles.Type); }
 			set { SetChildByRole (Roles.Type, value); }
@@ -51,7 +56,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (InitializerRole, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitArrayCreateExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitArrayCreateExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitArrayCreateExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/ArrayInitializerExpression.cs

@@ -58,7 +58,16 @@ namespace ICSharpCode.NRefactory.CSharp
 				}
 			}
 			
-			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return default (T);
+			}
+			
+			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 			{
 				return default (S);
 			}
@@ -82,7 +91,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.RBrace); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitArrayInitializerExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitArrayInitializerExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitArrayInitializerExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/AsExpression.cs

@@ -31,13 +31,15 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class AsExpression : Expression
 	{
+		public readonly static TokenRole AsKeywordRole = new TokenRole ("as");
+		
 		public Expression Expression {
 			get { return GetChildByRole (Roles.Expression); }
 			set { SetChildByRole(Roles.Expression, value); }
 		}
 		
 		public CSharpTokenNode AsToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (AsKeywordRole); }
 		}
 		
 		public AstType Type {
@@ -55,7 +57,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (type, Roles.Type);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitAsExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitAsExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitAsExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/AssignmentExpression.cs

@@ -36,9 +36,20 @@ namespace ICSharpCode.NRefactory.CSharp
 	{
 		// reuse roles from BinaryOperatorExpression
 		public readonly static Role<Expression> LeftRole = BinaryOperatorExpression.LeftRole;
-		public readonly static Role<CSharpTokenNode> OperatorRole = BinaryOperatorExpression.OperatorRole;
 		public readonly static Role<Expression> RightRole = BinaryOperatorExpression.RightRole;
 		
+		public readonly static TokenRole AssignRole = new TokenRole ("=");
+		public readonly static TokenRole AddRole = new TokenRole ("+=");
+		public readonly static TokenRole SubtractRole = new TokenRole ("-=");
+		public readonly static TokenRole MultiplyRole = new TokenRole ("*=");
+		public readonly static TokenRole DivideRole = new TokenRole ("/=");
+		public readonly static TokenRole ModulusRole = new TokenRole ("%=");
+		public readonly static TokenRole ShiftLeftRole = new TokenRole ("<<=");
+		public readonly static TokenRole ShiftRightRole = new TokenRole (">>=");
+		public readonly static TokenRole BitwiseAndRole = new TokenRole ("&=");
+		public readonly static TokenRole BitwiseOrRole = new TokenRole ("|=");
+		public readonly static TokenRole ExclusiveOrRole = new TokenRole ("^=");
+		
 		public AssignmentExpression()
 		{
 		}
@@ -67,7 +78,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public CSharpTokenNode OperatorToken {
-			get { return GetChildByRole (OperatorRole); }
+			get { return GetChildByRole (GetOperatorRole(Operator)); }
 		}
 		
 		public Expression Right {
@@ -75,7 +86,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole(RightRole, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitAssignmentExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitAssignmentExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitAssignmentExpression (this, data);
 		}
@@ -87,31 +108,31 @@ namespace ICSharpCode.NRefactory.CSharp
 				&& this.Left.DoMatch(o.Left, match) && this.Right.DoMatch(o.Right, match);
 		}
 		
-		public static string GetOperatorSymbol(AssignmentOperatorType op)
+		public static TokenRole GetOperatorRole(AssignmentOperatorType op)
 		{
 			switch (op) {
 				case AssignmentOperatorType.Assign:
-					return "=";
+					return AssignRole;
 				case AssignmentOperatorType.Add:
-					return "+=";
+					return AddRole;
 				case AssignmentOperatorType.Subtract:
-					return "-=";
+					return SubtractRole;
 				case AssignmentOperatorType.Multiply:
-					return "*=";
+					return MultiplyRole;
 				case AssignmentOperatorType.Divide:
-					return "/=";
+					return DivideRole;
 				case AssignmentOperatorType.Modulus:
-					return "%=";
+					return ModulusRole;
 				case AssignmentOperatorType.ShiftLeft:
-					return "<<=";
+					return ShiftLeftRole;
 				case AssignmentOperatorType.ShiftRight:
-					return ">>=";
+					return ShiftRightRole;
 				case AssignmentOperatorType.BitwiseAnd:
-					return "&=";
+					return BitwiseAndRole;
 				case AssignmentOperatorType.BitwiseOr:
-					return "|=";
+					return BitwiseOrRole;
 				case AssignmentOperatorType.ExclusiveOr:
-					return "^=";
+					return ExclusiveOrRole;
 				default:
 					throw new NotSupportedException("Invalid value for AssignmentOperatorType");
 			}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/BaseReferenceExpression.cs

@@ -47,7 +47,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitBaseReferenceExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitBaseReferenceExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitBaseReferenceExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/BinaryOperatorExpression.cs

@@ -34,8 +34,27 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class BinaryOperatorExpression : Expression
 	{
+		public readonly static TokenRole BitwiseAndRole = new TokenRole ("&");
+		public readonly static TokenRole BitwiseOrRole = new TokenRole ("|");
+		public readonly static TokenRole ConditionalAndRole = new TokenRole ("&&");
+		public readonly static TokenRole ConditionalOrRole = new TokenRole ("||");
+		public readonly static TokenRole ExclusiveOrRole = new TokenRole ("^");
+		public readonly static TokenRole GreaterThanRole = new TokenRole (">");
+		public readonly static TokenRole GreaterThanOrEqualRole = new TokenRole (">=");
+		public readonly static TokenRole EqualityRole = new TokenRole ("==");
+		public readonly static TokenRole InEqualityRole = new TokenRole ("!=");
+		public readonly static TokenRole LessThanRole = new TokenRole ("<");
+		public readonly static TokenRole LessThanOrEqualRole = new TokenRole ("<=");
+		public readonly static TokenRole AddRole = new TokenRole ("+");
+		public readonly static TokenRole SubtractRole = new TokenRole ("-");
+		public readonly static TokenRole MultiplyRole = new TokenRole ("*");
+		public readonly static TokenRole DivideRole = new TokenRole ("/");
+		public readonly static TokenRole ModulusRole = new TokenRole ("%");
+		public readonly static TokenRole ShiftLeftRole = new TokenRole ("<<");
+		public readonly static TokenRole ShiftRightRole = new TokenRole (">>");
+		public readonly static TokenRole NullCoalescingRole = new TokenRole ("??");
+		
 		public readonly static Role<Expression> LeftRole = new Role<Expression>("Left", Expression.Null);
-		public readonly static Role<CSharpTokenNode> OperatorRole = new Role<CSharpTokenNode>("Operator", CSharpTokenNode.Null);
 		public readonly static Role<Expression> RightRole = new Role<Expression>("Right", Expression.Null);
 		
 		public BinaryOperatorExpression()
@@ -60,15 +79,25 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public CSharpTokenNode OperatorToken {
-			get { return GetChildByRole (OperatorRole); }
+			get { return GetChildByRole (GetOperatorRole (Operator)); }
 		}
 		
 		public Expression Right {
 			get { return GetChildByRole (RightRole); }
-			set { SetChildByRole(RightRole, value); }
+			set { SetChildByRole (RightRole, value); }
+		}
+		
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitBinaryOperatorExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitBinaryOperatorExpression (this);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitBinaryOperatorExpression (this, data);
 		}
@@ -80,47 +109,47 @@ namespace ICSharpCode.NRefactory.CSharp
 				&& this.Left.DoMatch(o.Left, match) && this.Right.DoMatch(o.Right, match);
 		}
 		
-		public static string GetOperatorSymbol(BinaryOperatorType op)
+		public static TokenRole GetOperatorRole (BinaryOperatorType op)
 		{
 			switch (op) {
 				case BinaryOperatorType.BitwiseAnd:
-					return "&";
+					return BitwiseAndRole;
 				case BinaryOperatorType.BitwiseOr:
-					return "|";
+					return BitwiseOrRole;
 				case BinaryOperatorType.ConditionalAnd:
-					return "&&";
+					return ConditionalAndRole;
 				case BinaryOperatorType.ConditionalOr:
-					return "||";
+					return ConditionalOrRole;
 				case BinaryOperatorType.ExclusiveOr:
-					return "^";
+					return ExclusiveOrRole;
 				case BinaryOperatorType.GreaterThan:
-					return ">";
+					return GreaterThanRole;
 				case BinaryOperatorType.GreaterThanOrEqual:
-					return ">=";
+					return GreaterThanOrEqualRole;
 				case BinaryOperatorType.Equality:
-					return "==";
+					return EqualityRole;
 				case BinaryOperatorType.InEquality:
-					return "!=";
+					return InEqualityRole;
 				case BinaryOperatorType.LessThan:
-					return "<";
+					return LessThanRole;
 				case BinaryOperatorType.LessThanOrEqual:
-					return "<=";
+					return LessThanOrEqualRole;
 				case BinaryOperatorType.Add:
-					return "+";
+					return AddRole;
 				case BinaryOperatorType.Subtract:
-					return "-";
+					return SubtractRole;
 				case BinaryOperatorType.Multiply:
-					return "*";
+					return MultiplyRole;
 				case BinaryOperatorType.Divide:
-					return "/";
+					return DivideRole;
 				case BinaryOperatorType.Modulus:
-					return "%";
+					return ModulusRole;
 				case BinaryOperatorType.ShiftLeft:
-					return "<<";
+					return ShiftLeftRole;
 				case BinaryOperatorType.ShiftRight:
-					return ">>";
+					return ShiftRightRole;
 				case BinaryOperatorType.NullCoalescing:
-					return "??";
+					return NullCoalescingRole;
 				default:
 					throw new NotSupportedException("Invalid value for BinaryOperatorType");
 			}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/CastExpression.cs

@@ -59,7 +59,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (expression, Roles.Expression);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitCastExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitCastExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitCastExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/CheckedExpression.cs

@@ -31,8 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class CheckedExpression : Expression
 	{
+		public readonly static TokenRole CheckedKeywordRole = new TokenRole ("checked");
+		
 		public CSharpTokenNode CheckedToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (CheckedKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -57,7 +59,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (expression, Roles.Expression);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitCheckedExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitCheckedExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitCheckedExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/ConditionalExpression.cs

@@ -32,9 +32,9 @@ namespace ICSharpCode.NRefactory.CSharp
 	public class ConditionalExpression : Expression
 	{
 		public readonly static Role<Expression> ConditionRole = Roles.Condition;
-		public readonly static Role<CSharpTokenNode> QuestionMarkRole = new Role<CSharpTokenNode>("QuestionMark", CSharpTokenNode.Null);
+		public readonly static TokenRole QuestionMarkRole = new TokenRole("?");
 		public readonly static Role<Expression> TrueRole = new Role<Expression>("True", Expression.Null);
-		public readonly static Role<CSharpTokenNode> ColonRole = Roles.Colon;
+		public readonly static TokenRole ColonRole = Roles.Colon;
 		public readonly static Role<Expression> FalseRole = new Role<Expression>("False", Expression.Null);
 		
 		public Expression Condition {
@@ -71,7 +71,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (falseExpression, FalseRole);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitConditionalExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitConditionalExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitConditionalExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/DefaultValueExpression.cs

@@ -31,8 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class DefaultValueExpression : Expression
 	{
+		public readonly static TokenRole DefaultKeywordRole = new TokenRole ("default");
+
 		public CSharpTokenNode DefaultToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (DefaultKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -57,7 +59,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (type, Roles.Type);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitDefaultValueExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitDefaultValueExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitDefaultValueExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/DirectionExpression.cs

@@ -38,13 +38,16 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class DirectionExpression : Expression
 	{
+		public readonly static TokenRole RefKeywordRole = new TokenRole ("ref");
+		public readonly static TokenRole OutKeywordRole = new TokenRole ("out");
+		
 		public FieldDirection FieldDirection {
 			get;
 			set;
 		}
 		
 		public CSharpTokenNode FieldDirectionToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return FieldDirection == ICSharpCode.NRefactory.CSharp.FieldDirection.Ref ? GetChildByRole (RefKeywordRole) : GetChildByRole (OutKeywordRole); }
 		}
 		
 		public Expression Expression {
@@ -62,7 +65,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (expression, Roles.Expression);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitDirectionExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitDirectionExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitDirectionExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/EmptyExpression.cs

@@ -30,7 +30,7 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// <summary>
 	/// Type&lt;[EMPTY]&gt;
 	/// </summary>
-	public class EmptyExpression : Expression, IRelocatable
+	public class EmptyExpression : Expression
 	{
 		TextLocation location;
 
@@ -55,14 +55,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			this.location = location;
 		}
 		
-		#region IRelocationable implementation
-		void IRelocatable.SetStartLocation (TextLocation startLocation)
+		public override void AcceptVisitor (IAstVisitor visitor)
 		{
-			this.location = startLocation;
+			visitor.VisitEmptyExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitEmptyExpression (this);
 		}
-		#endregion
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitEmptyExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/ErrorExpression.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // ErrorExpression.cs
 //  
 // Author:
@@ -52,8 +52,18 @@ namespace ICSharpCode.NRefactory.CSharp
 			this.location = location;
 		}
 		
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			// nothing
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			// nothing
+			return default (T);
+		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			// nothing
 			return default(S);

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/Expression.cs

@@ -41,7 +41,16 @@ namespace ICSharpCode.NRefactory.CSharp
 				}
 			}
 			
-			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+			}
+			
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return default (T);
+			}
+			
+			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 			{
 				return default (S);
 			}
@@ -72,7 +81,17 @@ namespace ICSharpCode.NRefactory.CSharp
 				get { return NodeType.Pattern; }
 			}
 			
-			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+				visitor.VisitPatternPlaceholder(this, child);
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return visitor.VisitPatternPlaceholder(this, child);
+			}
+			
+			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 			{
 				return visitor.VisitPatternPlaceholder(this, child, data);
 			}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/IdentifierExpression.cs

@@ -52,7 +52,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value));
 			}
 		}
 		
@@ -60,7 +60,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildrenByRole (Roles.TypeArgument); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitIdentifierExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitIdentifierExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitIdentifierExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/IndexerExpression.cs

@@ -68,7 +68,17 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitIndexerExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitIndexerExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitIndexerExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/InvocationExpression.cs

@@ -50,7 +50,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.RPar); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitInvocationExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitInvocationExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitInvocationExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/IsExpression.cs

@@ -31,13 +31,15 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class IsExpression : Expression
 	{
+		public readonly static TokenRole IsKeywordRole = new TokenRole ("is");
+		
 		public Expression Expression {
 			get { return GetChildByRole(Roles.Expression); }
 			set { SetChildByRole(Roles.Expression, value); }
 		}
 		
 		public CSharpTokenNode IsToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (IsKeywordRole); }
 		}
 		
 		public AstType Type {
@@ -45,7 +47,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole(Roles.Type, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitIsExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitIsExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitIsExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/LambdaExpression.cs

@@ -33,11 +33,16 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class LambdaExpression : Expression
 	{
-		public readonly static Role<CSharpTokenNode> AsyncModifierRole = new Role<CSharpTokenNode>("AsyncModifier", CSharpTokenNode.Null);
-		public readonly static Role<CSharpTokenNode> ArrowRole = new Role<CSharpTokenNode>("Arrow", CSharpTokenNode.Null);
+		public readonly static TokenRole AsyncModifierRole = new TokenRole ("async");
+		public readonly static TokenRole ArrowRole = new TokenRole ("=>");
 		public static readonly Role<AstNode> BodyRole = new Role<AstNode>("Body", AstNode.Null);
 		
-		public bool IsAsync { get; set; }
+		bool isAsync;
+		
+		public bool IsAsync {
+			get { return isAsync; }
+			set { ThrowIfFrozen(); isAsync = value; }
+		}
 		
 		public AstNodeCollection<ParameterDeclaration> Parameters {
 			get { return GetChildrenByRole (Roles.Parameter); }
@@ -52,7 +57,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (BodyRole, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitLambdaExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitLambdaExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitLambdaExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/MemberReferenceExpression.cs

@@ -43,7 +43,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole (Roles.Identifier, Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole (Roles.Identifier, Identifier.Create (value));
 			}
 		}
 		
@@ -87,7 +87,17 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 		}	
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitMemberReferenceExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitMemberReferenceExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitMemberReferenceExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/NamedArgumentExpression.cs

@@ -41,7 +41,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value));
 			}
 		}
 		
@@ -63,7 +63,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Expression, value); }
 		}
 		
-		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitNamedArgumentExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitNamedArgumentExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitNamedArgumentExpression(this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/NamedExpression.cs

@@ -51,7 +51,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value));
 			}
 		}
 		
@@ -73,7 +73,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Expression, value); }
 		}
 		
-		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitNamedExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitNamedExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitNamedExpression(this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/NullReferenceExpression.cs

@@ -53,7 +53,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			this.location = location;
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitNullReferenceExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitNullReferenceExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitNullReferenceExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/ObjectCreateExpression.cs

@@ -33,10 +33,11 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class ObjectCreateExpression : Expression
 	{
+		public readonly static TokenRole NewKeywordRole = new TokenRole ("new");
 		public readonly static Role<ArrayInitializerExpression> InitializerRole = ArrayCreateExpression.InitializerRole;
 		
 		public CSharpTokenNode NewToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (NewKeywordRole); }
 		}
 		
 		public AstType Type {
@@ -79,7 +80,17 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitObjectCreateExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitObjectCreateExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitObjectCreateExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/ParenthesizedExpression.cs

@@ -53,7 +53,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			Expression = expr;
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitParenthesizedExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitParenthesizedExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitParenthesizedExpression (this, data);
 		}
@@ -81,7 +91,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		public static Expression UnpackParenthesizedExpression(Expression expr)
 		{
 			while (ActsAsParenthesizedExpression(expr))
-				expr = expr.GetChildByRole(ParenthesizedExpression.Roles.Expression);
+				expr = expr.GetChildByRole(Roles.Expression);
 			return expr;
 		}
 	}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/PointerReferenceExpression.cs

@@ -33,19 +33,23 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class PointerReferenceExpression : Expression
 	{
-		public readonly static Role<CSharpTokenNode> ArrowRole = new Role<CSharpTokenNode>("Arrow", CSharpTokenNode.Null);
+		public readonly static TokenRole ArrowRole = new TokenRole ("->");
 		
 		public Expression Target {
 			get { return GetChildByRole (Roles.TargetExpression); }
 			set { SetChildByRole(Roles.TargetExpression, value); }
 		}
 		
+		public CSharpTokenNode ArrowToken {
+			get { return GetChildByRole (ArrowRole); }
+		}
+
 		public string MemberName {
 			get {
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole(Roles.Identifier, Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(Roles.Identifier, Identifier.Create (value));
 			}
 		}
 		
@@ -53,7 +57,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildrenByRole (Roles.TypeArgument); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitPointerReferenceExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitPointerReferenceExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitPointerReferenceExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/PrimitiveExpression.cs

@@ -24,12 +24,14 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
+using System;
+
 namespace ICSharpCode.NRefactory.CSharp
 {
 	/// <summary>
 	/// Represents a literal value.
 	/// </summary>
-	public class PrimitiveExpression : Expression, IRelocatable
+	public class PrimitiveExpression : Expression
 	{
 		public static readonly object AnyValue = new object();
 		
@@ -47,20 +49,30 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
+		object value;
+		
 		public object Value {
-			get;
-			set;
+			get { return this.value; }
+			set { 
+				ThrowIfFrozen(); 
+				this.value = value;
+			}
 		}
 		
 		public string LiteralValue {
-			get {
-				return literalValue;
+			get { return literalValue; }
+			set {
+				if (value == null)
+					throw new ArgumentNullException();
+				ThrowIfFrozen();
+				literalValue = value;
 			}
 		}
 		
 		public PrimitiveExpression (object value)
 		{
 			this.Value = value;
+			this.literalValue = "";
 		}
 		
 		public PrimitiveExpression (object value, string literalValue)
@@ -76,14 +88,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			this.literalValue = literalValue ?? "";
 		}
 		
-		#region IRelocationable implementation
-		void IRelocatable.SetStartLocation (TextLocation startLocation)
+		public override void AcceptVisitor (IAstVisitor visitor)
 		{
-			this.startLocation = startLocation;
+			visitor.VisitPrimitiveExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitPrimitiveExpression (this);
 		}
-		#endregion
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitPrimitiveExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/QueryExpression.cs

@@ -36,7 +36,16 @@ namespace ICSharpCode.NRefactory.CSharp
 				}
 			}
 			
-			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return default (T);
+			}
+		
+			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 			{
 				return default (S);
 			}
@@ -52,7 +61,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildrenByRole(ClauseRole); }
 		}
 		
-		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitQueryExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitQueryExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitQueryExpression (this, data);
 		}
@@ -92,7 +111,7 @@ namespace ICSharpCode.NRefactory.CSharp
 	public class QueryContinuationClause : QueryClause
 	{
 		public static readonly Role<QueryExpression> PrecedingQueryRole = new Role<QueryExpression>("PrecedingQuery", QueryExpression.Null);
-		public static readonly Role<CSharpTokenNode> IntoKeywordRole = Roles.Keyword;
+		public static readonly TokenRole IntoKeywordRole = new TokenRole ("into");
 		
 		public QueryExpression PrecedingQuery {
 			get { return GetChildByRole(PrecedingQueryRole); }
@@ -104,7 +123,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value));
 			}
 		}
 		
@@ -112,7 +131,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.Identifier); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitQueryContinuationClause (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitQueryContinuationClause (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitQueryContinuationClause (this, data);
 		}
@@ -126,8 +155,8 @@ namespace ICSharpCode.NRefactory.CSharp
 	
 	public class QueryFromClause : QueryClause
 	{
-		public static readonly Role<CSharpTokenNode> FromKeywordRole = Roles.Keyword;
-		public static readonly Role<CSharpTokenNode> InKeywordRole = Roles.InKeyword;
+		public static readonly TokenRole FromKeywordRole =  new TokenRole ("from");
+		public static readonly TokenRole InKeywordRole =  new TokenRole ("in");
 		
 		public AstType Type {
 			get { return GetChildByRole (Roles.Type); }
@@ -139,7 +168,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value));
 			}
 		}
 		
@@ -152,7 +181,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Expression, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitQueryFromClause (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitQueryFromClause (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitQueryFromClause (this, data);
 		}
@@ -167,8 +206,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	
 	public class QueryLetClause : QueryClause
 	{
+		public readonly static TokenRole LetKeywordRole = new TokenRole ("let");
+		
 		public CSharpTokenNode LetKeyword {
-			get { return GetChildByRole(Roles.Keyword); }
+			get { return GetChildByRole(LetKeywordRole); }
 		}
 		
 		public string Identifier {
@@ -176,7 +217,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole(Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(Roles.Identifier, CSharp.Identifier.Create (value));
 			}
 		}
 		
@@ -193,7 +234,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole(Roles.Expression, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitQueryLetClause (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitQueryLetClause (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitQueryLetClause (this, data);
 		}
@@ -208,8 +259,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	
 	public class QueryWhereClause : QueryClause
 	{
+		public readonly static TokenRole WhereKeywordRole = new TokenRole ("where");
+
 		public CSharpTokenNode WhereKeyword {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (WhereKeywordRole); }
 		}
 		
 		public Expression Condition {
@@ -217,7 +270,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Condition, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitQueryWhereClause (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitQueryWhereClause (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitQueryWhereClause (this, data);
 		}
@@ -234,16 +297,16 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class QueryJoinClause : QueryClause
 	{
-		public static readonly Role<CSharpTokenNode> JoinKeywordRole = Roles.Keyword;
+		public static readonly TokenRole JoinKeywordRole = new TokenRole ("join");
 		public static readonly Role<AstType> TypeRole = Roles.Type;
 		public static readonly Role<Identifier> JoinIdentifierRole = Roles.Identifier;
-		public static readonly Role<CSharpTokenNode> InKeywordRole = Roles.InKeyword;
+		public static readonly TokenRole InKeywordRole =  new TokenRole ("in");
 		public static readonly Role<Expression> InExpressionRole = Roles.Expression;
-		public static readonly Role<CSharpTokenNode> OnKeywordRole = new Role<CSharpTokenNode>("OnKeyword", CSharpTokenNode.Null);
+		public static readonly TokenRole OnKeywordRole =  new TokenRole ("on");
 		public static readonly Role<Expression> OnExpressionRole = new Role<Expression>("OnExpression", Expression.Null);
-		public static readonly Role<CSharpTokenNode> EqualsKeywordRole = new Role<CSharpTokenNode>("EqualsKeyword", CSharpTokenNode.Null);
+		public static readonly TokenRole EqualsKeywordRole =  new TokenRole ("equals");
 		public static readonly Role<Expression> EqualsExpressionRole = new Role<Expression>("EqualsExpression", Expression.Null);
-		public static readonly Role<CSharpTokenNode> IntoKeywordRole = new Role<CSharpTokenNode>("IntoKeyword", CSharpTokenNode.Null);
+		public static readonly TokenRole IntoKeywordRole =  new TokenRole ("into");
 		public static readonly Role<Identifier> IntoIdentifierRole = new Role<Identifier>("IntoIdentifier", Identifier.Null);
 		
 		public bool IsGroupJoin {
@@ -264,7 +327,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole(JoinIdentifierRole).Name;
 			}
 			set {
-				SetChildByRole(JoinIdentifierRole, Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(JoinIdentifierRole, Identifier.Create (value));
 			}
 		}
 		
@@ -308,7 +371,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (IntoIdentifierRole).Name;
 			}
 			set {
-				SetChildByRole(IntoIdentifierRole, Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(IntoIdentifierRole, Identifier.Create (value));
 			}
 		}
 		
@@ -316,7 +379,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole(IntoIdentifierRole); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitQueryJoinClause (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitQueryJoinClause (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitQueryJoinClause (this, data);
 		}
@@ -334,17 +407,28 @@ namespace ICSharpCode.NRefactory.CSharp
 	
 	public class QueryOrderClause : QueryClause
 	{
+		public static readonly TokenRole OrderbyKeywordRole = new TokenRole ("orderby");
 		public static readonly Role<QueryOrdering> OrderingRole = new Role<QueryOrdering>("Ordering");
 		
-		public CSharpTokenNode Keyword {
-			get { return GetChildByRole (Roles.Keyword); }
+		public CSharpTokenNode OrderbyToken {
+			get { return GetChildByRole (OrderbyKeywordRole); }
 		}
 		
 		public AstNodeCollection<QueryOrdering> Orderings {
 			get { return GetChildrenByRole (OrderingRole); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitQueryOrderClause (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitQueryOrderClause (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitQueryOrderClause (this, data);
 		}
@@ -358,6 +442,9 @@ namespace ICSharpCode.NRefactory.CSharp
 	
 	public class QueryOrdering : AstNode
 	{
+		public readonly static TokenRole AscendingKeywordRole = new TokenRole ("ascending");
+		public readonly static TokenRole DescendingKeywordRole = new TokenRole ("descending");
+
 		public override NodeType NodeType {
 			get { return NodeType.Unknown; }
 		}
@@ -373,10 +460,20 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public CSharpTokenNode DirectionToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return Direction == QueryOrderingDirection.Ascending ? GetChildByRole (AscendingKeywordRole) : GetChildByRole (DescendingKeywordRole); }
+		}
+		
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitQueryOrdering (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitQueryOrdering (this);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitQueryOrdering (this, data);
 		}
@@ -397,8 +494,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	
 	public class QuerySelectClause : QueryClause
 	{
+		public readonly static TokenRole SelectKeywordRole = new TokenRole ("select");
+
 		public CSharpTokenNode SelectKeyword {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (SelectKeywordRole); }
 		}
 		
 		public Expression Expression {
@@ -406,7 +505,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Expression, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitQuerySelectClause (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitQuerySelectClause (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitQuerySelectClause (this, data);
 		}
@@ -420,9 +529,9 @@ namespace ICSharpCode.NRefactory.CSharp
 	
 	public class QueryGroupClause : QueryClause
 	{
-		public static readonly Role<CSharpTokenNode> GroupKeywordRole = Roles.Keyword;
+		public static readonly TokenRole GroupKeywordRole = new TokenRole ("group");
 		public static readonly Role<Expression> ProjectionRole = new Role<Expression>("Projection", Expression.Null);
-		public static readonly Role<CSharpTokenNode> ByKeywordRole = new Role<CSharpTokenNode>("ByKeyword", CSharpTokenNode.Null);
+		public static readonly TokenRole ByKeywordRole = new TokenRole ("by");
 		public static readonly Role<Expression> KeyRole = new Role<Expression>("Key", Expression.Null);
 		
 		public CSharpTokenNode GroupKeyword {
@@ -443,7 +552,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (KeyRole, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitQueryGroupClause (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitQueryGroupClause (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitQueryGroupClause (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/SizeOfExpression.cs

@@ -31,8 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class SizeOfExpression : Expression
 	{
+		public readonly static TokenRole SizeofKeywordRole = new TokenRole ("sizeof");
+		
 		public CSharpTokenNode SizeOfToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (SizeofKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -57,7 +59,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (type, Roles.Type);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitSizeOfExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitSizeOfExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitSizeOfExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/StackAllocExpression.cs

@@ -31,8 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class StackAllocExpression : Expression
 	{
+		public readonly static TokenRole StackallocKeywordRole = new TokenRole ("stackalloc");
+		
 		public CSharpTokenNode StackAllocToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (StackallocKeywordRole); }
 		}
 		
 		public AstType Type {
@@ -53,7 +55,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.RBracket); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitStackAllocExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitStackAllocExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitStackAllocExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/ThisReferenceExpression.cs

@@ -46,8 +46,18 @@ namespace ICSharpCode.NRefactory.CSharp
 				return new TextLocation (Location.Line, Location.Column + "this".Length);
 			}
 		}
-
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitThisReferenceExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitThisReferenceExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitThisReferenceExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/TypeOfExpression.cs

@@ -32,8 +32,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class TypeOfExpression : Expression
 	{
+		public readonly static TokenRole TypeofKeywordRole = new TokenRole ("typeof");
+		
 		public CSharpTokenNode TypeOfToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (TypeofKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -58,7 +60,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (type, Roles.Type);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitTypeOfExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitTypeOfExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitTypeOfExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/TypeReferenceExpression.cs

@@ -31,7 +31,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole(Roles.Type, value); }
 		}
 		
-		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitTypeReferenceExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitTypeReferenceExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitTypeReferenceExpression(this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/UnaryOperatorExpression.cs

@@ -34,7 +34,15 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class UnaryOperatorExpression : Expression
 	{
-		public readonly static Role<CSharpTokenNode> OperatorRole = BinaryOperatorExpression.OperatorRole;
+		public readonly static TokenRole NotRole = new TokenRole ("!");
+		public readonly static TokenRole BitNotRole = new TokenRole ("~");
+		public readonly static TokenRole MinusRole = new TokenRole ("-");
+		public readonly static TokenRole PlusRole = new TokenRole ("+");
+		public readonly static TokenRole IncrementRole = new TokenRole ("++");
+		public readonly static TokenRole DecrementRole = new TokenRole ("--");
+		public readonly static TokenRole DereferenceRole = new TokenRole ("*");
+		public readonly static TokenRole AddressOfRole = new TokenRole ("&");
+		public readonly static TokenRole AwaitRole = new TokenRole ("await");
 		
 		public UnaryOperatorExpression()
 		{
@@ -52,7 +60,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public CSharpTokenNode OperatorToken {
-			get { return GetChildByRole (OperatorRole); }
+			get { return GetChildByRole (GetOperatorRole (Operator)); }
 		}
 		
 		public Expression Expression {
@@ -60,7 +68,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Expression, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitUnaryOperatorExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitUnaryOperatorExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitUnaryOperatorExpression (this, data);
 		}
@@ -72,29 +90,29 @@ namespace ICSharpCode.NRefactory.CSharp
 				&& this.Expression.DoMatch(o.Expression, match);
 		}
 		
-		public static string GetOperatorSymbol(UnaryOperatorType op)
+		public static TokenRole GetOperatorRole(UnaryOperatorType op)
 		{
 			switch (op) {
 				case UnaryOperatorType.Not:
-					return "!";
+					return NotRole;
 				case UnaryOperatorType.BitNot:
-					return "~";
+					return BitNotRole;
 				case UnaryOperatorType.Minus:
-					return "-";
+					return MinusRole;
 				case UnaryOperatorType.Plus:
-					return "+";
+					return PlusRole;
 				case UnaryOperatorType.Increment:
 				case UnaryOperatorType.PostIncrement:
-					return "++";
+					return IncrementRole;
 				case UnaryOperatorType.PostDecrement:
 				case UnaryOperatorType.Decrement:
-					return "--";
+					return DecrementRole;
 				case UnaryOperatorType.Dereference:
-					return "*";
+					return DereferenceRole;
 				case UnaryOperatorType.AddressOf:
-					return "&";
+					return AddressOfRole;
 				case UnaryOperatorType.Await:
-					return "await";
+					return AwaitRole;
 				default:
 					throw new NotSupportedException("Invalid value for UnaryOperatorType");
 			}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/UncheckedExpression.cs

@@ -31,8 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class UncheckedExpression : Expression
 	{
+		public readonly static TokenRole UncheckedKeywordRole = new TokenRole ("unchecked");
+
 		public CSharpTokenNode UncheckedToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (UncheckedKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -57,7 +59,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (expression, Roles.Expression);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitUncheckedExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitUncheckedExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitUncheckedExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Expressions/UndocumentedExpression.cs

@@ -42,12 +42,30 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class UndocumentedExpression : Expression
 	{
+		public readonly static TokenRole ArglistKeywordRole = new TokenRole ("__arglist");
+		public readonly static TokenRole RefvalueKeywordRole = new TokenRole ("__refvalue");
+		public readonly static TokenRole ReftypeKeywordRole = new TokenRole ("__reftype");
+		public readonly static TokenRole MakerefKeywordRole = new TokenRole ("__makeref");
+		
 		public UndocumentedExpressionType UndocumentedExpressionType {
 			get; set;
 		}
 		
 		public CSharpTokenNode UndocumentedToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get {
+				switch (UndocumentedExpressionType) {
+				case ICSharpCode.NRefactory.CSharp.UndocumentedExpressionType.ArgListAccess:
+				case ICSharpCode.NRefactory.CSharp.UndocumentedExpressionType.ArgList:
+					return GetChildByRole (ArglistKeywordRole);
+				case ICSharpCode.NRefactory.CSharp.UndocumentedExpressionType.RefValue:
+					return GetChildByRole (RefvalueKeywordRole);
+				case ICSharpCode.NRefactory.CSharp.UndocumentedExpressionType.RefType:
+					return GetChildByRole (ReftypeKeywordRole);
+				case ICSharpCode.NRefactory.CSharp.UndocumentedExpressionType.MakeRef:
+					return GetChildByRole (MakerefKeywordRole);
+				}
+				return CSharpTokenNode.Null;
+			}
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -62,7 +80,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.RPar); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitUndocumentedExpression (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitUndocumentedExpression (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitUndocumentedExpression (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/Attribute.cs

@@ -54,7 +54,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set;
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitAttribute (this);
+		}
+		
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitAttribute (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitAttribute (this, data);
 		}
@@ -69,9 +79,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 			if (IsNull)
 				return "Null";
-			var w = new System.IO.StringWriter ();
-			AcceptVisitor (new CSharpOutputVisitor (w, new CSharpFormattingOptions ()), null);
-			return w.ToString ();
+			else
+				return GetText();
 		}
 	}
 }

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/AttributeSection.cs

@@ -54,7 +54,17 @@ namespace ICSharpCode.NRefactory.CSharp
 				get { return NodeType.Pattern; }
 			}
 			
-			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+				visitor.VisitPatternPlaceholder (this, child);
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return visitor.VisitPatternPlaceholder (this, child);
+			}
+			
+			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 			{
 				return visitor.VisitPatternPlaceholder(this, child, data);
 			}
@@ -71,9 +81,6 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		#endregion
 		
-		public static readonly Role<Attribute> AttributeRole = new Role<Attribute>("Attribute");
-		public static readonly Role<CSharpTokenNode> TargetRole = new Role<CSharpTokenNode>("Target", CSharpTokenNode.Null);
-		
 		public override NodeType NodeType {
 			get {
 				return NodeType.Unknown;
@@ -89,7 +96,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole (Roles.Identifier, CSharp.Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole (Roles.Identifier, CSharp.Identifier.Create (value));
 			}
 		}
 		
@@ -103,14 +110,24 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public AstNodeCollection<Attribute> Attributes {
-			get { return base.GetChildrenByRole (AttributeRole); }
+			get { return base.GetChildrenByRole (Roles.Attribute); }
 		}
 		
 		public CSharpTokenNode RBracketToken {
 			get { return GetChildByRole (Roles.RBracket); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitAttributeSection (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitAttributeSection (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitAttributeSection (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/Comment.cs

@@ -43,10 +43,14 @@ namespace ICSharpCode.NRefactory.CSharp
 		/// <summary>
 		/// Inactive code (code in non-taken "#if")
 		/// </summary>
-		InactiveCode
+		InactiveCode,
+		/// <summary>
+		/// "/** */" comment
+		/// </summary>
+		MultiLineDocumentation
 	}
 	
-	public class Comment : AstNode, IRelocatable
+	public class Comment : AstNode
 	{
 		public override NodeType NodeType {
 			get {
@@ -54,19 +58,25 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
+		CommentType commentType;
+		
 		public CommentType CommentType {
-			get;
-			set;
+			get { return commentType; }
+			set { ThrowIfFrozen(); commentType = value; }
 		}
 		
+		bool startsLine;
+		
 		public bool StartsLine {
-			get;
-			set;
+			get { return startsLine; }
+			set { ThrowIfFrozen(); startsLine = value; }
 		}
 		
+		string content;
+		
 		public string Content {
-			get;
-			set;
+			get { return content; }
+			set { ThrowIfFrozen(); content = value; }
 		}
 		
 		TextLocation startLocation;
@@ -96,16 +106,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			this.endLocation = endLocation;
 		}
 		
-		#region IRelocationable implementation
-		void IRelocatable.SetStartLocation (TextLocation startLocation)
+		public override void AcceptVisitor (IAstVisitor visitor)
 		{
-			int lineDelta = startLocation.Line - this.startLocation.Line;
-			endLocation = new TextLocation (endLocation.Line + lineDelta, lineDelta != 0 ? endLocation.Column : endLocation.Column + startLocation.Column - this.startLocation.Column);
-			this.startLocation = startLocation;
+			visitor.VisitComment (this);
 		}
-		#endregion
-
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitComment (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitComment (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/Constraint.cs

@@ -36,10 +36,6 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </remarks>
 	public class Constraint : AstNode
 	{
-		public readonly static Role<CSharpTokenNode> ColonRole = TypeDeclaration.ColonRole;
-		public readonly static Role<AstType> BaseTypeRole = TypeDeclaration.BaseTypeRole;
-		public readonly static Role<SimpleType> TypeParameterRole = new Role<SimpleType> ("TypeParameter", SimpleType.Null);
-		
 		public override NodeType NodeType {
 			get {
 				return NodeType.Unknown;
@@ -48,18 +44,29 @@ namespace ICSharpCode.NRefactory.CSharp
 		
 		public SimpleType TypeParameter {
 			get {
-				return GetChildByRole (TypeParameterRole);
+				return GetChildByRole (Roles.ConstraintTypeParameter);
 			}
 			set {
-				SetChildByRole(TypeParameterRole, value);
+				SetChildByRole(Roles.ConstraintTypeParameter, value);
 			}
 		}
 		
 		public AstNodeCollection<AstType> BaseTypes {
-			get { return GetChildrenByRole (BaseTypeRole); }
+			get {
+				return GetChildrenByRole(Roles.BaseType); }
+		}
+		
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitConstraint (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitConstraint (this);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitConstraint (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/DelegateDeclaration.cs

@@ -24,45 +24,27 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-using System.Collections.Generic;
-using System.Linq;
+using ICSharpCode.NRefactory.TypeSystem;
 
 namespace ICSharpCode.NRefactory.CSharp
 {
 	/// <summary>
 	/// delegate ReturnType Name&lt;TypeParameters&gt;(Parameters) where Constraints;
 	/// </summary>
-	public class DelegateDeclaration : AttributedNode
+	public class DelegateDeclaration : EntityDeclaration
 	{
 		public override NodeType NodeType {
-			get {
-				return NodeType.TypeDeclaration;
-			}
+			get { return NodeType.TypeDeclaration; }
 		}
 		
-		public AstType ReturnType {
-			get { return GetChildByRole (Roles.Type); }
-			set { SetChildByRole (Roles.Type, value); }
+		public override EntityType EntityType {
+			get { return EntityType.TypeDefinition; }
 		}
 		
-		public string Name {
-			get {
-				return GetChildByRole (Roles.Identifier).Name;
-			}
-			set {
-				SetChildByRole (Roles.Identifier, Identifier.Create (value, TextLocation.Empty));
-			}
+		public CSharpTokenNode DelegateToken {
+			get { return GetChildByRole(Roles.DelegateKeyword); }
 		}
-		
-		public Identifier NameToken {
-			get {
-				return GetChildByRole (Roles.Identifier);
-			}
-			set {
-				SetChildByRole (Roles.Identifier, value);
-			}
-		}
-		
+
 		public AstNodeCollection<TypeParameterDeclaration> TypeParameters {
 			get { return GetChildrenByRole (Roles.TypeParameter); }
 		}
@@ -83,7 +65,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildrenByRole (Roles.Constraint); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitDelegateDeclaration (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitDelegateDeclaration (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitDelegateDeclaration (this, data);
 		}
@@ -91,8 +83,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
 		{
 			DelegateDeclaration o = other as DelegateDeclaration;
-			return o != null && this.MatchAttributesAndModifiers(o, match)
-				&& this.ReturnType.DoMatch(o.ReturnType, match) && MatchString(this.Name, o.Name)
+			return o != null && MatchString(this.Name, o.Name) 
+				&& this.MatchAttributesAndModifiers(o, match) && this.ReturnType.DoMatch(o.ReturnType, match)
 				&& this.TypeParameters.DoMatch(o.TypeParameters, match) && this.Parameters.DoMatch(o.Parameters, match)
 				&& this.Constraints.DoMatch(o.Constraints, match);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/ExternAliasDeclaration.cs

@@ -31,8 +31,6 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class ExternAliasDeclaration : AstNode
 	{
-		public static readonly Role<CSharpTokenNode> AliasRole = new Role<CSharpTokenNode> ("Alias", CSharpTokenNode.Null);
-
 		public override NodeType NodeType {
 			get {
 				return NodeType.Unknown;
@@ -40,11 +38,11 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 
 		public CSharpTokenNode ExternToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (Roles.ExternKeyword); }
 		}
 
 		public CSharpTokenNode AliasToken {
-			get { return GetChildByRole (AliasRole); }
+			get { return GetChildByRole (Roles.AliasKeyword); }
 		}
 
 		public string Name {
@@ -52,7 +50,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole (Roles.Identifier, Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole (Roles.Identifier, Identifier.Create (value));
 			}
 		}
 		
@@ -69,7 +67,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.Semicolon); }
 		}
 
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitExternAliasDeclaration (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitExternAliasDeclaration (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitExternAliasDeclaration (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/NamespaceDeclaration.cs

@@ -43,6 +43,10 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
+		public CSharpTokenNode NamespaceToken {
+			get { return GetChildByRole (Roles.NamespaceKeyword); }
+		}
+		
 		public string Name {
 			get {
 				StringBuilder builder = new StringBuilder ();
@@ -54,7 +58,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return builder.ToString ();
 			}
 			set {
-				GetChildrenByRole(Roles.Identifier).ReplaceWith(value.Split('.').Select(ident => Identifier.Create (ident, TextLocation.Empty)));
+				GetChildrenByRole(Roles.Identifier).ReplaceWith(value.Split('.').Select(ident => Identifier.Create (ident)));
 			}
 		}
 		
@@ -109,7 +113,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (child, MemberRole);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitNamespaceDeclaration (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitNamespaceDeclaration (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitNamespaceDeclaration (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/NewLineNode.cs

@@ -0,0 +1,132 @@
+using System;
+namespace ICSharpCode.NRefactory.CSharp
+{
+	public enum NewLineType {
+		Unix,
+		Windows,
+		Mac
+	}
+
+	/// <summary>
+	/// A New line node represents a line break in the text.
+	/// </summary>
+	public abstract class NewLineNode : AstNode
+	{
+		public override NodeType NodeType {
+			get {
+				return NodeType.Whitespace;
+			}
+		}
+
+		public abstract NewLineType NewLineType {
+			get;
+		}
+
+		TextLocation startLocation;
+		public override TextLocation StartLocation {
+			get { 
+				return startLocation;
+			}
+		}
+		
+		public override TextLocation EndLocation {
+			get {
+				return new TextLocation (startLocation.Line + 1, 1);
+			}
+		}
+
+		public NewLineNode() : this (TextLocation.Empty)
+		{
+		}
+
+		public NewLineNode(TextLocation startLocation)
+		{
+			this.startLocation = startLocation;
+		}
+
+		public override void AcceptVisitor(IAstVisitor visitor)
+		{
+			visitor.VisitNewLine (this);
+		}
+			
+		public override T AcceptVisitor<T>(IAstVisitor<T> visitor)
+		{
+			return visitor.VisitNewLine (this);
+		}
+		
+		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
+		{
+			return visitor.VisitNewLine (this, data);
+		}
+	}
+
+	public class UnixNewLine : NewLineNode
+	{
+		public override NewLineType NewLineType {
+			get {
+				return NewLineType.Unix;
+			}
+		}
+
+		public UnixNewLine()
+		{
+		}
+
+		public UnixNewLine(TextLocation startLocation) : base (startLocation)
+		{
+		}
+
+		protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
+		{
+			var o = other as UnixNewLine;
+			return o != null;
+		}
+	}
+
+	public class WindowsNewLine : NewLineNode
+	{
+		public override NewLineType NewLineType {
+			get {
+				return NewLineType.Windows;
+			}
+		}
+
+		public WindowsNewLine()
+		{
+		}
+
+		public WindowsNewLine(TextLocation startLocation) : base (startLocation)
+		{
+		}
+
+		protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
+		{
+			var o = other as WindowsNewLine;
+			return o != null;
+		}
+	}
+
+	public class MacNewLine : NewLineNode
+	{
+		public override NewLineType NewLineType {
+			get {
+				return NewLineType.Mac;
+			}
+		}
+
+		public MacNewLine()
+		{
+		}
+
+		public MacNewLine(TextLocation startLocation) : base (startLocation)
+		{
+		}
+
+		protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
+		{
+			var o = other as MacNewLine;
+			return o != null;
+		}
+	}
+}
+

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/PreProcessorDirective.cs

@@ -46,7 +46,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		Line = 12
 	}
 	
-	public class PreProcessorDirective : AstNode, IRelocatable
+	public class PreProcessorDirective : AstNode
 	{
 		public override NodeType NodeType {
 			get {
@@ -93,16 +93,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			this.endLocation = endLocation;
 		}
 		
-		#region IRelocationable implementation
-		void IRelocatable.SetStartLocation (TextLocation startLocation)
+		public override void AcceptVisitor (IAstVisitor visitor)
 		{
-			int lineDelta = startLocation.Line - this.startLocation.Line;
-			endLocation = new TextLocation (endLocation.Line + lineDelta, lineDelta != 0 ? endLocation.Column : endLocation.Column + startLocation.Column - this.startLocation.Column);
-			this.startLocation = startLocation;
+			visitor.VisitPreProcessorDirective (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitPreProcessorDirective (this);
 		}
-		#endregion
 
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitPreProcessorDirective (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/TextNode.cs

@@ -0,0 +1,94 @@
+// 
+// TextNode.cs
+//  
+// Author:
+//       Mike Krüger <mkrueger@xamarin.com>
+// 
+// Copyright (c) 2012 Xamarin Inc. (http://xamarin.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.
+
+using System;
+namespace ICSharpCode.NRefactory.CSharp
+{
+	/// <summary>
+	/// A text node contains text without syntactic or semantic information.
+	/// (non parseable part of a text)
+	/// </summary>
+	public class TextNode : AstNode
+	{
+		public override NodeType NodeType {
+			get {
+				return NodeType.Whitespace;
+			}
+		}
+
+		public string Text {
+			get;
+			set;
+		}
+
+		TextLocation startLocation;
+		public override TextLocation StartLocation {
+			get { 
+				return startLocation;
+			}
+		}
+		
+		TextLocation endLocation;
+		public override TextLocation EndLocation {
+			get {
+				return endLocation;
+			}
+		}
+
+		public TextNode(string text) : this (text, TextLocation.Empty, TextLocation.Empty)
+		{
+		}
+
+		public TextNode(string text, TextLocation startLocation, TextLocation endLocation)
+		{
+			this.Text = text;
+			this.startLocation = startLocation;
+			this.endLocation = endLocation;
+		}
+
+		public override void AcceptVisitor(IAstVisitor visitor)
+		{
+			visitor.VisitText (this);
+		}
+
+		public override T AcceptVisitor<T>(IAstVisitor<T> visitor)
+		{
+			return visitor.VisitText (this);
+		}
+
+		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
+		{
+			return visitor.VisitText (this, data);
+		}
+
+		protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
+		{
+			var o = other as TextNode;
+			return o != null && o.Text == Text;
+		}
+	}
+}
+

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/TypeDeclaration.cs

@@ -41,66 +41,78 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// <summary>
 	/// class Name&lt;TypeParameters&gt; : BaseTypes where Constraints;
 	/// </summary>
-	public class TypeDeclaration : AttributedNode
+	public class TypeDeclaration : EntityDeclaration
 	{
-		public readonly static Role<CSharpTokenNode> ColonRole = Roles.Colon;
-		public readonly static Role<AstType> BaseTypeRole = new Role<AstType>("BaseType", AstType.Null);
-		public readonly static Role<AttributedNode> MemberRole = new Role<AttributedNode>("Member");
-		
 		public override NodeType NodeType {
-			get {
-				return NodeType.TypeDeclaration;
-			}
+			get { return NodeType.TypeDeclaration; }
 		}
 		
-		public ClassType ClassType {
-			get;
-			set;
+		public override EntityType EntityType {
+			get { return EntityType.TypeDefinition; }
 		}
 		
-		public string Name {
+		ClassType classType;
+
+		public CSharpTokenNode TypeKeyword {
 			get {
-				return GetChildByRole (Roles.Identifier).Name;
-			}
-			set {
-				SetChildByRole (Roles.Identifier, Identifier.Create (value, TextLocation.Empty));
+				switch (classType) {
+					case ClassType.Class:
+						return GetChildByRole(Roles.ClassKeyword);
+					case ClassType.Struct:
+						return GetChildByRole(Roles.StructKeyword);
+					case ClassType.Interface:
+						return GetChildByRole(Roles.InterfaceKeyword);
+					case ClassType.Enum:
+						return GetChildByRole(Roles.EnumKeyword);
+					default:
+						return CSharpTokenNode.Null;
+				}
 			}
 		}
 		
-		public Identifier NameToken {
-			get {
-				return GetChildByRole (Roles.Identifier);
-			}
+		public ClassType ClassType {
+			get { return classType; }
 			set {
-				SetChildByRole (Roles.Identifier, value);
+				ThrowIfFrozen();
+				classType = value;
 			}
 		}
-		
+
 		public AstNodeCollection<TypeParameterDeclaration> TypeParameters {
 			get { return GetChildrenByRole (Roles.TypeParameter); }
 		}
 		
 		public AstNodeCollection<AstType> BaseTypes {
-			get { return GetChildrenByRole (BaseTypeRole); }
+			get { return GetChildrenByRole(Roles.BaseType); }
 		}
 		
 		public AstNodeCollection<Constraint> Constraints {
-			get { return GetChildrenByRole (Roles.Constraint); }
+			get { return GetChildrenByRole(Roles.Constraint); }
 		}
 		
 		public CSharpTokenNode LBraceToken {
 			get { return GetChildByRole (Roles.LBrace); }
 		}
 		
-		public AstNodeCollection<AttributedNode> Members {
-			get { return GetChildrenByRole (MemberRole); }
+		public AstNodeCollection<EntityDeclaration> Members {
+			get { return GetChildrenByRole (Roles.TypeMemberRole); }
 		}
 		
 		public CSharpTokenNode RBraceToken {
 			get { return GetChildByRole (Roles.RBrace); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitTypeDeclaration (this);
+		}
+		
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitTypeDeclaration (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitTypeDeclaration (this, data);
 		}
@@ -108,8 +120,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
 		{
 			TypeDeclaration o = other as TypeDeclaration;
-			return o != null && this.ClassType == o.ClassType && this.MatchAttributesAndModifiers(o, match)
-				&& MatchString(this.Name, o.Name) && this.TypeParameters.DoMatch(o.TypeParameters, match)
+			return o != null && this.ClassType == o.ClassType && MatchString(this.Name, o.Name)
+				&& this.MatchAttributesAndModifiers(o, match) && this.TypeParameters.DoMatch(o.TypeParameters, match)
 				&& this.BaseTypes.DoMatch(o.BaseTypes, match) && this.Constraints.DoMatch(o.Constraints, match)
 				&& this.Members.DoMatch(o.Members, match);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/TypeParameterDeclaration.cs

@@ -30,8 +30,9 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class TypeParameterDeclaration : AstNode
 	{
-		public static readonly Role<AttributeSection> AttributeRole = AttributedNode.AttributeRole;
-		public static readonly Role<CSharpTokenNode> VarianceRole = new Role<CSharpTokenNode>("Variance", CSharpTokenNode.Null);
+		public static readonly Role<AttributeSection> AttributeRole = EntityDeclaration.AttributeRole;
+		public static readonly TokenRole OutVarianceKeywordRole = new TokenRole ("out");
+		public static readonly TokenRole InVarianceKeywordRole = new TokenRole ("in");
 		
 		public override NodeType NodeType {
 			get { return NodeType.Unknown; }
@@ -41,8 +42,24 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildrenByRole (AttributeRole); }
 		}
 		
+		VarianceModifier variance;
+		
 		public VarianceModifier Variance {
-			get; set;
+			get { return variance; }
+			set { ThrowIfFrozen(); variance = value; }
+		}
+		
+		public CSharpTokenNode VarianceToken {
+			get {
+				switch (Variance) {
+					case VarianceModifier.Covariant:
+						return GetChildByRole(OutVarianceKeywordRole);
+					case VarianceModifier.Contravariant:
+						return GetChildByRole(InVarianceKeywordRole);
+					default:
+						return CSharpTokenNode.Null;
+				}
+			}
 		}
 		
 		public string Name {
@@ -50,7 +67,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole(Roles.Identifier, Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(Roles.Identifier, Identifier.Create (value));
 			}
 		}
 		
@@ -62,8 +79,27 @@ namespace ICSharpCode.NRefactory.CSharp
 				SetChildByRole (Roles.Identifier, value);
 			}
 		}
+
+		public TypeParameterDeclaration ()
+		{
+		}
+
+		public TypeParameterDeclaration (string name)
+		{
+			Name = name;
+		}
+
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitTypeParameterDeclaration (this);
+		}
+		
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitTypeParameterDeclaration (this);
+		}
 		
-		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitTypeParameterDeclaration(this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/UsingAliasDeclaration.cs

@@ -31,6 +31,7 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class UsingAliasDeclaration : AstNode
 	{
+		public static readonly TokenRole UsingKeywordRole = new TokenRole ("using");
 		public static readonly Role<Identifier> AliasRole = new Role<Identifier>("Alias", Identifier.Null);
 		public static readonly Role<AstType> ImportRole = UsingDeclaration.ImportRole;
 		
@@ -41,7 +42,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public CSharpTokenNode UsingToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (UsingKeywordRole); }
 		}
 		
 		public string Alias {
@@ -49,7 +50,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (AliasRole).Name;
 			}
 			set {
-				SetChildByRole(AliasRole, Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(AliasRole, Identifier.Create (value));
 			}
 		}
 		
@@ -72,17 +73,27 @@ namespace ICSharpCode.NRefactory.CSharp
 		
 		public UsingAliasDeclaration (string alias, string nameSpace)
 		{
-			AddChild (Identifier.Create (alias, TextLocation.Empty), AliasRole);
+			AddChild (Identifier.Create (alias), AliasRole);
 			AddChild (new SimpleType (nameSpace), ImportRole);
 		}
 		
 		public UsingAliasDeclaration (string alias, AstType import)
 		{
-			AddChild (Identifier.Create (alias, TextLocation.Empty), AliasRole);
+			AddChild (Identifier.Create (alias), AliasRole);
 			AddChild (import, ImportRole);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitUsingAliasDeclaration (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitUsingAliasDeclaration (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitUsingAliasDeclaration (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/UsingDeclaration.cs

@@ -35,6 +35,7 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class UsingDeclaration : AstNode
 	{
+		public static readonly TokenRole UsingKeywordRole = new TokenRole ("using");
 		public static readonly Role<AstType> ImportRole = new Role<AstType>("Import", AstType.Null);
 		
 		public override NodeType NodeType {
@@ -44,7 +45,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public CSharpTokenNode UsingToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (UsingKeywordRole); }
 		}
 		
 		public AstType Import {
@@ -74,7 +75,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (import, ImportRole);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitUsingDeclaration (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitUsingDeclaration (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitUsingDeclaration (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/GeneralScope/WhitespaceNode.cs

@@ -0,0 +1,91 @@
+// 
+// WhitespaceNode.cs
+//  
+// Author:
+//       Mike Krüger <mkrueger@xamarin.com>
+// 
+// Copyright (c) 2012 Xamarin Inc. (http://xamarin.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.
+
+using System;
+namespace ICSharpCode.NRefactory.CSharp
+{
+	/// <summary>
+	/// A Whitespace node contains only whitespaces.
+	/// </summary>
+	public class WhitespaceNode : AstNode
+	{
+		public override NodeType NodeType {
+			get {
+				return NodeType.Whitespace;
+			}
+		}
+
+		public string WhiteSpaceText {
+			get;
+			set;
+		}
+
+		TextLocation startLocation;
+		public override TextLocation StartLocation {
+			get { 
+				return startLocation;
+			}
+		}
+		
+		public override TextLocation EndLocation {
+			get {
+				return new TextLocation (startLocation.Line, startLocation.Column + WhiteSpaceText.Length);
+			}
+		}
+
+		public WhitespaceNode(string whiteSpaceText) : this (whiteSpaceText, TextLocation.Empty)
+		{
+		}
+
+		public WhitespaceNode(string whiteSpaceText, TextLocation startLocation)
+		{
+			this.WhiteSpaceText = WhiteSpaceText;
+			this.startLocation = startLocation;
+		}
+
+		public override void AcceptVisitor(IAstVisitor visitor)
+		{
+			visitor.VisitWhitespace (this);
+		}
+
+		public override T AcceptVisitor<T>(IAstVisitor<T> visitor)
+		{
+			return visitor.VisitWhitespace (this);
+		}
+
+		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
+		{
+			return visitor.VisitWhitespace (this, data);
+		}
+
+		protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
+		{
+			var o = other as WhitespaceNode;
+			return o != null && o.WhiteSpaceText == WhiteSpaceText;
+		}
+	}
+}
+

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/IAstVisitor.cs

@@ -20,6 +20,268 @@ using System;
 
 namespace ICSharpCode.NRefactory.CSharp
 {
+	/// <summary>
+	/// AST visitor.
+	/// </summary>
+	public interface IAstVisitor
+	{
+		void VisitAnonymousMethodExpression(AnonymousMethodExpression anonymousMethodExpression);
+		void VisitUndocumentedExpression(UndocumentedExpression undocumentedExpression);
+		void VisitArrayCreateExpression(ArrayCreateExpression arrayCreateExpression);
+		void VisitArrayInitializerExpression(ArrayInitializerExpression arrayInitializerExpression);
+		void VisitAsExpression(AsExpression asExpression);
+		void VisitAssignmentExpression(AssignmentExpression assignmentExpression);
+		void VisitBaseReferenceExpression(BaseReferenceExpression baseReferenceExpression);
+		void VisitBinaryOperatorExpression(BinaryOperatorExpression binaryOperatorExpression);
+		void VisitCastExpression(CastExpression castExpression);
+		void VisitCheckedExpression(CheckedExpression checkedExpression);
+		void VisitConditionalExpression(ConditionalExpression conditionalExpression);
+		void VisitDefaultValueExpression(DefaultValueExpression defaultValueExpression);
+		void VisitDirectionExpression(DirectionExpression directionExpression);
+		void VisitIdentifierExpression(IdentifierExpression identifierExpression);
+		void VisitIndexerExpression(IndexerExpression indexerExpression);
+		void VisitInvocationExpression(InvocationExpression invocationExpression);
+		void VisitIsExpression(IsExpression isExpression);
+		void VisitLambdaExpression(LambdaExpression lambdaExpression);
+		void VisitMemberReferenceExpression(MemberReferenceExpression memberReferenceExpression);
+		void VisitNamedArgumentExpression(NamedArgumentExpression namedArgumentExpression);
+		void VisitNamedExpression(NamedExpression namedExpression);
+		void VisitNullReferenceExpression(NullReferenceExpression nullReferenceExpression);
+		void VisitObjectCreateExpression(ObjectCreateExpression objectCreateExpression);
+		void VisitAnonymousTypeCreateExpression(AnonymousTypeCreateExpression anonymousTypeCreateExpression);
+		void VisitParenthesizedExpression(ParenthesizedExpression parenthesizedExpression);
+		void VisitPointerReferenceExpression(PointerReferenceExpression pointerReferenceExpression);
+		void VisitPrimitiveExpression(PrimitiveExpression primitiveExpression);
+		void VisitSizeOfExpression(SizeOfExpression sizeOfExpression);
+		void VisitStackAllocExpression(StackAllocExpression stackAllocExpression);
+		void VisitThisReferenceExpression(ThisReferenceExpression thisReferenceExpression);
+		void VisitTypeOfExpression(TypeOfExpression typeOfExpression);
+		void VisitTypeReferenceExpression(TypeReferenceExpression typeReferenceExpression);
+		void VisitUnaryOperatorExpression(UnaryOperatorExpression unaryOperatorExpression);
+		void VisitUncheckedExpression(UncheckedExpression uncheckedExpression);
+		void VisitEmptyExpression (EmptyExpression emptyExpression);
+		
+		void VisitQueryExpression(QueryExpression queryExpression);
+		void VisitQueryContinuationClause(QueryContinuationClause queryContinuationClause);
+		void VisitQueryFromClause(QueryFromClause queryFromClause);
+		void VisitQueryLetClause(QueryLetClause queryLetClause);
+		void VisitQueryWhereClause(QueryWhereClause queryWhereClause);
+		void VisitQueryJoinClause(QueryJoinClause queryJoinClause);
+		void VisitQueryOrderClause(QueryOrderClause queryOrderClause);
+		void VisitQueryOrdering(QueryOrdering queryOrdering);
+		void VisitQuerySelectClause(QuerySelectClause querySelectClause);
+		void VisitQueryGroupClause(QueryGroupClause queryGroupClause);
+		
+		void VisitAttribute(Attribute attribute);
+		void VisitAttributeSection(AttributeSection attributeSection);
+		void VisitDelegateDeclaration(DelegateDeclaration delegateDeclaration);
+		void VisitNamespaceDeclaration(NamespaceDeclaration namespaceDeclaration);
+		void VisitTypeDeclaration(TypeDeclaration typeDeclaration);
+		void VisitUsingAliasDeclaration(UsingAliasDeclaration usingAliasDeclaration);
+		void VisitUsingDeclaration(UsingDeclaration usingDeclaration);
+		void VisitExternAliasDeclaration(ExternAliasDeclaration externAliasDeclaration);
+		
+		void VisitBlockStatement(BlockStatement blockStatement);
+		void VisitBreakStatement(BreakStatement breakStatement);
+		void VisitCheckedStatement(CheckedStatement checkedStatement);
+		void VisitContinueStatement(ContinueStatement continueStatement);
+		void VisitDoWhileStatement(DoWhileStatement doWhileStatement);
+		void VisitEmptyStatement(EmptyStatement emptyStatement);
+		void VisitExpressionStatement(ExpressionStatement expressionStatement);
+		void VisitFixedStatement(FixedStatement fixedStatement);
+		void VisitForeachStatement(ForeachStatement foreachStatement);
+		void VisitForStatement(ForStatement forStatement);
+		void VisitGotoCaseStatement(GotoCaseStatement gotoCaseStatement);
+		void VisitGotoDefaultStatement(GotoDefaultStatement gotoDefaultStatement);
+		void VisitGotoStatement(GotoStatement gotoStatement);
+		void VisitIfElseStatement(IfElseStatement ifElseStatement);
+		void VisitLabelStatement(LabelStatement labelStatement);
+		void VisitLockStatement(LockStatement lockStatement);
+		void VisitReturnStatement(ReturnStatement returnStatement);
+		void VisitSwitchStatement(SwitchStatement switchStatement);
+		void VisitSwitchSection(SwitchSection switchSection);
+		void VisitCaseLabel(CaseLabel caseLabel);
+		void VisitThrowStatement(ThrowStatement throwStatement);
+		void VisitTryCatchStatement(TryCatchStatement tryCatchStatement);
+		void VisitCatchClause(CatchClause catchClause);
+		void VisitUncheckedStatement(UncheckedStatement uncheckedStatement);
+		void VisitUnsafeStatement(UnsafeStatement unsafeStatement);
+		void VisitUsingStatement(UsingStatement usingStatement);
+		void VisitVariableDeclarationStatement(VariableDeclarationStatement variableDeclarationStatement);
+		void VisitWhileStatement(WhileStatement whileStatement);
+		void VisitYieldBreakStatement(YieldBreakStatement yieldBreakStatement);
+		void VisitYieldReturnStatement(YieldReturnStatement yieldReturnStatement);
+		
+		void VisitAccessor(Accessor accessor);
+		void VisitConstructorDeclaration(ConstructorDeclaration constructorDeclaration);
+		void VisitConstructorInitializer(ConstructorInitializer constructorInitializer);
+		void VisitDestructorDeclaration(DestructorDeclaration destructorDeclaration);
+		void VisitEnumMemberDeclaration(EnumMemberDeclaration enumMemberDeclaration);
+		void VisitEventDeclaration(EventDeclaration eventDeclaration);
+		void VisitCustomEventDeclaration(CustomEventDeclaration customEventDeclaration);
+		void VisitFieldDeclaration(FieldDeclaration fieldDeclaration);
+		void VisitIndexerDeclaration(IndexerDeclaration indexerDeclaration);
+		void VisitMethodDeclaration(MethodDeclaration methodDeclaration);
+		void VisitOperatorDeclaration(OperatorDeclaration operatorDeclaration);
+		void VisitParameterDeclaration(ParameterDeclaration parameterDeclaration);
+		void VisitPropertyDeclaration(PropertyDeclaration propertyDeclaration);
+		void VisitVariableInitializer(VariableInitializer variableInitializer);
+		void VisitFixedFieldDeclaration(FixedFieldDeclaration fixedFieldDeclaration);
+		void VisitFixedVariableInitializer(FixedVariableInitializer fixedVariableInitializer);
+		
+		void VisitCompilationUnit(CompilationUnit compilationUnit);
+		void VisitSimpleType(SimpleType simpleType);
+		void VisitMemberType(MemberType memberType);
+		void VisitComposedType(ComposedType composedType);
+		void VisitArraySpecifier(ArraySpecifier arraySpecifier);
+		void VisitPrimitiveType(PrimitiveType primitiveType);
+		
+		void VisitComment(Comment comment);
+		void VisitNewLine(NewLineNode newLineNode);
+		void VisitWhitespace(WhitespaceNode whitespaceNode);
+		void VisitText(TextNode textNode);
+		void VisitPreProcessorDirective(PreProcessorDirective preProcessorDirective);
+		void VisitDocumentationReference(DocumentationReference documentationReference);
+		
+		void VisitTypeParameterDeclaration(TypeParameterDeclaration typeParameterDeclaration);
+		void VisitConstraint(Constraint constraint);
+		void VisitCSharpTokenNode(CSharpTokenNode cSharpTokenNode);
+		void VisitIdentifier(Identifier identifier);
+		
+		void VisitPatternPlaceholder(AstNode placeholder, PatternMatching.Pattern pattern);
+	}
+	
+	/// <summary>
+	/// AST visitor.
+	/// </summary>
+	public interface IAstVisitor<out S>
+	{
+		S VisitAnonymousMethodExpression(AnonymousMethodExpression anonymousMethodExpression);
+		S VisitUndocumentedExpression(UndocumentedExpression undocumentedExpression);
+		S VisitArrayCreateExpression(ArrayCreateExpression arrayCreateExpression);
+		S VisitArrayInitializerExpression(ArrayInitializerExpression arrayInitializerExpression);
+		S VisitAsExpression(AsExpression asExpression);
+		S VisitAssignmentExpression(AssignmentExpression assignmentExpression);
+		S VisitBaseReferenceExpression(BaseReferenceExpression baseReferenceExpression);
+		S VisitBinaryOperatorExpression(BinaryOperatorExpression binaryOperatorExpression);
+		S VisitCastExpression(CastExpression castExpression);
+		S VisitCheckedExpression(CheckedExpression checkedExpression);
+		S VisitConditionalExpression(ConditionalExpression conditionalExpression);
+		S VisitDefaultValueExpression(DefaultValueExpression defaultValueExpression);
+		S VisitDirectionExpression(DirectionExpression directionExpression);
+		S VisitIdentifierExpression(IdentifierExpression identifierExpression);
+		S VisitIndexerExpression(IndexerExpression indexerExpression);
+		S VisitInvocationExpression(InvocationExpression invocationExpression);
+		S VisitIsExpression(IsExpression isExpression);
+		S VisitLambdaExpression(LambdaExpression lambdaExpression);
+		S VisitMemberReferenceExpression(MemberReferenceExpression memberReferenceExpression);
+		S VisitNamedArgumentExpression(NamedArgumentExpression namedArgumentExpression);
+		S VisitNamedExpression(NamedExpression namedExpression);
+		S VisitNullReferenceExpression(NullReferenceExpression nullReferenceExpression);
+		S VisitObjectCreateExpression(ObjectCreateExpression objectCreateExpression);
+		S VisitAnonymousTypeCreateExpression(AnonymousTypeCreateExpression anonymousTypeCreateExpression);
+		S VisitParenthesizedExpression(ParenthesizedExpression parenthesizedExpression);
+		S VisitPointerReferenceExpression(PointerReferenceExpression pointerReferenceExpression);
+		S VisitPrimitiveExpression(PrimitiveExpression primitiveExpression);
+		S VisitSizeOfExpression(SizeOfExpression sizeOfExpression);
+		S VisitStackAllocExpression(StackAllocExpression stackAllocExpression);
+		S VisitThisReferenceExpression(ThisReferenceExpression thisReferenceExpression);
+		S VisitTypeOfExpression(TypeOfExpression typeOfExpression);
+		S VisitTypeReferenceExpression(TypeReferenceExpression typeReferenceExpression);
+		S VisitUnaryOperatorExpression(UnaryOperatorExpression unaryOperatorExpression);
+		S VisitUncheckedExpression(UncheckedExpression uncheckedExpression);
+		S VisitEmptyExpression (EmptyExpression emptyExpression);
+		
+		S VisitQueryExpression(QueryExpression queryExpression);
+		S VisitQueryContinuationClause(QueryContinuationClause queryContinuationClause);
+		S VisitQueryFromClause(QueryFromClause queryFromClause);
+		S VisitQueryLetClause(QueryLetClause queryLetClause);
+		S VisitQueryWhereClause(QueryWhereClause queryWhereClause);
+		S VisitQueryJoinClause(QueryJoinClause queryJoinClause);
+		S VisitQueryOrderClause(QueryOrderClause queryOrderClause);
+		S VisitQueryOrdering(QueryOrdering queryOrdering);
+		S VisitQuerySelectClause(QuerySelectClause querySelectClause);
+		S VisitQueryGroupClause(QueryGroupClause queryGroupClause);
+		
+		S VisitAttribute(Attribute attribute);
+		S VisitAttributeSection(AttributeSection attributeSection);
+		S VisitDelegateDeclaration(DelegateDeclaration delegateDeclaration);
+		S VisitNamespaceDeclaration(NamespaceDeclaration namespaceDeclaration);
+		S VisitTypeDeclaration(TypeDeclaration typeDeclaration);
+		S VisitUsingAliasDeclaration(UsingAliasDeclaration usingAliasDeclaration);
+		S VisitUsingDeclaration(UsingDeclaration usingDeclaration);
+		S VisitExternAliasDeclaration(ExternAliasDeclaration externAliasDeclaration);
+		
+		S VisitBlockStatement(BlockStatement blockStatement);
+		S VisitBreakStatement(BreakStatement breakStatement);
+		S VisitCheckedStatement(CheckedStatement checkedStatement);
+		S VisitContinueStatement(ContinueStatement continueStatement);
+		S VisitDoWhileStatement(DoWhileStatement doWhileStatement);
+		S VisitEmptyStatement(EmptyStatement emptyStatement);
+		S VisitExpressionStatement(ExpressionStatement expressionStatement);
+		S VisitFixedStatement(FixedStatement fixedStatement);
+		S VisitForeachStatement(ForeachStatement foreachStatement);
+		S VisitForStatement(ForStatement forStatement);
+		S VisitGotoCaseStatement(GotoCaseStatement gotoCaseStatement);
+		S VisitGotoDefaultStatement(GotoDefaultStatement gotoDefaultStatement);
+		S VisitGotoStatement(GotoStatement gotoStatement);
+		S VisitIfElseStatement(IfElseStatement ifElseStatement);
+		S VisitLabelStatement(LabelStatement labelStatement);
+		S VisitLockStatement(LockStatement lockStatement);
+		S VisitReturnStatement(ReturnStatement returnStatement);
+		S VisitSwitchStatement(SwitchStatement switchStatement);
+		S VisitSwitchSection(SwitchSection switchSection);
+		S VisitCaseLabel(CaseLabel caseLabel);
+		S VisitThrowStatement(ThrowStatement throwStatement);
+		S VisitTryCatchStatement(TryCatchStatement tryCatchStatement);
+		S VisitCatchClause(CatchClause catchClause);
+		S VisitUncheckedStatement(UncheckedStatement uncheckedStatement);
+		S VisitUnsafeStatement(UnsafeStatement unsafeStatement);
+		S VisitUsingStatement(UsingStatement usingStatement);
+		S VisitVariableDeclarationStatement(VariableDeclarationStatement variableDeclarationStatement);
+		S VisitWhileStatement(WhileStatement whileStatement);
+		S VisitYieldBreakStatement(YieldBreakStatement yieldBreakStatement);
+		S VisitYieldReturnStatement(YieldReturnStatement yieldReturnStatement);
+		
+		S VisitAccessor(Accessor accessor);
+		S VisitConstructorDeclaration(ConstructorDeclaration constructorDeclaration);
+		S VisitConstructorInitializer(ConstructorInitializer constructorInitializer);
+		S VisitDestructorDeclaration(DestructorDeclaration destructorDeclaration);
+		S VisitEnumMemberDeclaration(EnumMemberDeclaration enumMemberDeclaration);
+		S VisitEventDeclaration(EventDeclaration eventDeclaration);
+		S VisitCustomEventDeclaration(CustomEventDeclaration customEventDeclaration);
+		S VisitFieldDeclaration(FieldDeclaration fieldDeclaration);
+		S VisitIndexerDeclaration(IndexerDeclaration indexerDeclaration);
+		S VisitMethodDeclaration(MethodDeclaration methodDeclaration);
+		S VisitOperatorDeclaration(OperatorDeclaration operatorDeclaration);
+		S VisitParameterDeclaration(ParameterDeclaration parameterDeclaration);
+		S VisitPropertyDeclaration(PropertyDeclaration propertyDeclaration);
+		S VisitVariableInitializer(VariableInitializer variableInitializer);
+		S VisitFixedFieldDeclaration(FixedFieldDeclaration fixedFieldDeclaration);
+		S VisitFixedVariableInitializer(FixedVariableInitializer fixedVariableInitializer);
+		
+		S VisitCompilationUnit(CompilationUnit compilationUnit);
+		S VisitSimpleType(SimpleType simpleType);
+		S VisitMemberType(MemberType memberType);
+		S VisitComposedType(ComposedType composedType);
+		S VisitArraySpecifier(ArraySpecifier arraySpecifier);
+		S VisitPrimitiveType(PrimitiveType primitiveType);
+		
+		S VisitComment(Comment comment);
+		S VisitWhitespace(WhitespaceNode whitespaceNode);
+		S VisitText(TextNode textNode);
+		S VisitNewLine(NewLineNode newLineNode);
+		S VisitPreProcessorDirective(PreProcessorDirective preProcessorDirective);
+		S VisitDocumentationReference(DocumentationReference documentationReference);
+		
+		S VisitTypeParameterDeclaration(TypeParameterDeclaration typeParameterDeclaration);
+		S VisitConstraint(Constraint constraint);
+		S VisitCSharpTokenNode(CSharpTokenNode cSharpTokenNode);
+		S VisitIdentifier(Identifier identifier);
+		
+		S VisitPatternPlaceholder(AstNode placeholder, PatternMatching.Pattern pattern);
+	}
+	
 	/// <summary>
 	/// AST visitor.
 	/// </summary>
@@ -137,7 +399,11 @@ namespace ICSharpCode.NRefactory.CSharp
 		S VisitPrimitiveType(PrimitiveType primitiveType, T data);
 		
 		S VisitComment(Comment comment, T data);
+		S VisitNewLine(NewLineNode newLineNode, T data);
+		S VisitWhitespace(WhitespaceNode whitespaceNode, T data);
+		S VisitText(TextNode textNode, T data);
 		S VisitPreProcessorDirective(PreProcessorDirective preProcessorDirective, T data);
+		S VisitDocumentationReference(DocumentationReference documentationReference, T data);
 		
 		S VisitTypeParameterDeclaration(TypeParameterDeclaration typeParameterDeclaration, T data);
 		S VisitConstraint(Constraint constraint, T data);

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Identifier.cs

@@ -1,6 +1,6 @@
 // 
 // Identifier.cs
-//  
+//
 // Author:
 //       Mike Krüger <mkrueger@novell.com>
 // 
@@ -28,7 +28,7 @@ using System;
 
 namespace ICSharpCode.NRefactory.CSharp
 {
-	public class Identifier : AstNode, IRelocatable
+	public class Identifier : AstNode
 	{
 		public new static readonly Identifier Null = new NullIdentifier ();
 		sealed class NullIdentifier : Identifier
@@ -39,7 +39,16 @@ namespace ICSharpCode.NRefactory.CSharp
 				}
 			}
 			
-			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+			}
+			
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return default (T);
+			}
+			
+			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 			{
 				return default (S);
 			}
@@ -59,9 +68,10 @@ namespace ICSharpCode.NRefactory.CSharp
 		string name;
 		public string Name {
 			get { return this.name; }
-			set { 
+			set {
 				if (value == null)
 					throw new ArgumentNullException("value");
+				ThrowIfFrozen();
 				this.name = value;
 			}
 		}
@@ -71,25 +81,26 @@ namespace ICSharpCode.NRefactory.CSharp
 			get {
 				return startLocation;
 			}
-			
 		}
 		
-		public virtual bool IsVerbatim {
+		const uint verbatimBit = 1u << AstNodeFlagsUsedBits;
+		
+		public bool IsVerbatim {
 			get {
-				return false;
+				return (flags & verbatimBit) != 0;
+			}
+			set {
+				ThrowIfFrozen();
+				if (value)
+					flags |= verbatimBit;
+				else
+					flags &= ~verbatimBit;
 			}
 		}
 		
-		#region IRelocationable implementation
-		void IRelocatable.SetStartLocation (TextLocation startLocation)
-		{
-			this.startLocation = startLocation;
-		}
-		#endregion
-		
 		public override TextLocation EndLocation {
 			get {
-				return new TextLocation (StartLocation.Line, StartLocation.Column + (Name ?? "").Length);
+				return new TextLocation (StartLocation.Line, StartLocation.Column + (Name ?? "").Length + (IsVerbatim ? 1 : 0));
 			}
 		}
 		
@@ -116,22 +127,32 @@ namespace ICSharpCode.NRefactory.CSharp
 			if (string.IsNullOrEmpty(name))
 				return Identifier.Null;
 			if (name[0] == '@')
-				return new VerbatimIdentifier(name.Substring (1), location);
+				return new Identifier (name.Substring (1), location) { IsVerbatim = true };
 			else
 				return new Identifier (name, location);
 		}
 		
 		public static Identifier Create (string name, TextLocation location, bool isVerbatim)
 		{
-			if (string.IsNullOrEmpty(name))
+			if (string.IsNullOrEmpty (name))
 				return Identifier.Null;
 			
 			if (isVerbatim)
-				return new VerbatimIdentifier(name, location);
+				return new Identifier (name, location) { IsVerbatim = true };
 			return new Identifier (name, location);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitIdentifier (this);
+		}
+		
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitIdentifier (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitIdentifier (this, data);
 		}
@@ -141,24 +162,5 @@ namespace ICSharpCode.NRefactory.CSharp
 			Identifier o = other as Identifier;
 			return o != null && !o.IsNull && MatchString(this.Name, o.Name);
 		}
-
-		class VerbatimIdentifier : Identifier
-		{
-			public override TextLocation EndLocation {
-				get {
-					return new TextLocation (StartLocation.Line, StartLocation.Column + (Name ?? "").Length + 1); // @"..."
-				}
-			}
-			
-			public override bool IsVerbatim {
-				get {
-					return true;
-				}
-			}
-			
-			public VerbatimIdentifier(string name, TextLocation location) : base (name, location)
-			{
-			}
-		}
 	}
 }

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/IdentifierExpressionBackreference.cs

@@ -48,7 +48,7 @@ namespace ICSharpCode.NRefactory.CSharp
 			CSharp.AstNode referenced = (CSharp.AstNode)match.Get(referencedGroupName).Last();
 			if (referenced == null)
 				return false;
-			return ident.Identifier == referenced.GetChildByRole(CSharp.AstNode.Roles.Identifier).Name;
+			return ident.Identifier == referenced.GetChildByRole(CSharp.Roles.Identifier).Name;
 		}
 	}
 }

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/MemberType.cs

@@ -37,7 +37,15 @@ namespace ICSharpCode.NRefactory.CSharp
 	{
 		public static readonly Role<AstType> TargetRole = new Role<AstType>("Target", AstType.Null);
 		
-		public bool IsDoubleColon { get; set; }
+		bool isDoubleColon;
+		
+		public bool IsDoubleColon {
+			get { return isDoubleColon; }
+			set {
+				ThrowIfFrozen();
+				isDoubleColon = value;
+			}
+		}
 		
 		public AstType Target {
 			get { return GetChildByRole(TargetRole); }
@@ -49,7 +57,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole (Roles.Identifier, Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole (Roles.Identifier, Identifier.Create (value));
 			}
 		}
 		
@@ -89,7 +97,17 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitMemberType (this);
+		}
+		
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitMemberType (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitMemberType (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/ObservableAstVisitor.cs

@@ -60,9 +60,38 @@ namespace ICSharpCode.NRefactory.CSharp
 				handler (comment, data);
 			return VisitChildren (comment, data);
 		}
-		
-		public event Action<PreProcessorDirective, T> PreProcessorDirectiveVisited;
 
+		public event Action<NewLineNode, T> NewLineVisited;
+
+		S IAstVisitor<T, S>.VisitNewLine(NewLineNode newLineNode, T data)
+		{
+			var handler = NewLineVisited;
+			if (handler != null)
+				handler(newLineNode, data);
+			return VisitChildren(newLineNode, data);
+		}
+
+		public event Action<WhitespaceNode, T> WhitespaceVisited;
+
+		S IAstVisitor<T, S>.VisitWhitespace(WhitespaceNode whitespace, T data)
+		{
+			var handler = WhitespaceVisited;
+			if (handler != null)
+				handler(whitespace, data);
+			return VisitChildren(whitespace, data);
+		}
+
+		public event Action<TextNode, T> TextVisited;
+
+		S IAstVisitor<T, S>.VisitText(TextNode textNode, T data)
+		{
+			var handler = TextVisited;
+			if (handler != null)
+				handler(textNode, data);
+			return VisitChildren(textNode, data);
+		}
+
+		public event Action<PreProcessorDirective, T> PreProcessorDirectiveVisited;
 		S IAstVisitor<T, S>.VisitPreProcessorDirective (PreProcessorDirective preProcessorDirective, T data)
 		{
 			var handler = PreProcessorDirectiveVisited;
@@ -71,6 +100,16 @@ namespace ICSharpCode.NRefactory.CSharp
 			return VisitChildren (preProcessorDirective, data);
 		}
 		
+		public event Action<DocumentationReference, T> DocumentationReferenceVisited;
+
+		S IAstVisitor<T, S>.VisitDocumentationReference (DocumentationReference documentationReference, T data)
+		{
+			var handler = DocumentationReferenceVisited;
+			if (handler != null)
+				handler (documentationReference, data);
+			return VisitChildren (documentationReference, data);
+		}
+		
 		public event Action<Identifier, T> IdentifierVisited;
 
 		S IAstVisitor<T, S>.VisitIdentifier (Identifier identifier, T data)

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/PrimitiveType.cs

@@ -32,10 +32,20 @@ using ICSharpCode.NRefactory.TypeSystem.Implementation;
 
 namespace ICSharpCode.NRefactory.CSharp
 {
-	public class PrimitiveType : AstType, IRelocatable
+	public class PrimitiveType : AstType
 	{
-		public string Keyword { get; set; }
-		public TextLocation Location { get; set; }
+		TextLocation location;
+		string keyword = string.Empty;
+		
+		public string Keyword {
+			get { return keyword; }
+			set { 
+				if (value == null)
+					throw new ArgumentNullException();
+				ThrowIfFrozen();
+				keyword = value; 
+			}
+		}
 		
 		public KnownTypeCode KnownTypeCode {
 			get { return GetTypeCodeForPrimitiveType(this.Keyword); }
@@ -53,29 +63,31 @@ namespace ICSharpCode.NRefactory.CSharp
 		public PrimitiveType(string keyword, TextLocation location)
 		{
 			this.Keyword = keyword;
-			this.Location = location;
+			this.location = location;
 		}
 		
 		public override TextLocation StartLocation {
 			get {
-				return Location;
+				return location;
 			}
 		}
 		public override TextLocation EndLocation {
 			get {
-				return new TextLocation (Location.Line, Location.Column + (Keyword != null ? Keyword.Length : 0));
+				return new TextLocation (location.Line, location.Column + keyword.Length);
 			}
 		}
 		
-		
-		#region IRelocationable implementation
-		void IRelocatable.SetStartLocation (TextLocation startLocation)
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitPrimitiveType (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
 		{
-			this.Location = startLocation;
+			return visitor.VisitPrimitiveType (this);
 		}
-		#endregion
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitPrimitiveType (this, data);
 		}
@@ -88,7 +100,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		
 		public override string ToString()
 		{
-			return Keyword ?? base.ToString();
+			return Keyword;
 		}
 		
 		public override ITypeReference ToTypeReference(SimpleNameLookupMode lookupMode = SimpleNameLookupMode.Type)

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Roles.cs

@@ -0,0 +1,96 @@
+// 
+// Roles.cs
+//  
+// Author:
+//       Mike Krüger <mkrueger@xamarin.com>
+// 
+// Copyright (c) 2012 Xamarin <http://xamarin.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.
+
+using System;
+
+namespace ICSharpCode.NRefactory.CSharp
+{
+	public static class Roles
+	{
+		public static readonly Role<AstNode> Root = AstNode.RootRole;
+		
+		// some pre defined constants for common roles
+		public static readonly Role<Identifier> Identifier = new Role<Identifier> ("Identifier", CSharp.Identifier.Null);
+		public static readonly Role<BlockStatement> Body = new Role<BlockStatement> ("Body", CSharp.BlockStatement.Null);
+		public static readonly Role<ParameterDeclaration> Parameter = new Role<ParameterDeclaration> ("Parameter");
+		public static readonly Role<Expression> Argument = new Role<Expression> ("Argument", CSharp.Expression.Null);
+		public static readonly Role<AstType> Type = new Role<AstType> ("Type", CSharp.AstType.Null);
+		public static readonly Role<Expression> Expression = new Role<Expression> ("Expression", CSharp.Expression.Null);
+		public static readonly Role<Expression> TargetExpression = new Role<Expression> ("Target", CSharp.Expression.Null);
+		public readonly static Role<Expression> Condition = new Role<Expression> ("Condition", CSharp.Expression.Null);
+		public static readonly Role<TypeParameterDeclaration> TypeParameter = new Role<TypeParameterDeclaration> ("TypeParameter");
+		public static readonly Role<AstType> TypeArgument = new Role<AstType> ("TypeArgument", CSharp.AstType.Null);
+		public readonly static Role<Constraint> Constraint = new Role<Constraint> ("Constraint");
+		public static readonly Role<VariableInitializer> Variable = new Role<VariableInitializer> ("Variable", VariableInitializer.Null);
+		public static readonly Role<Statement> EmbeddedStatement = new Role<Statement> ("EmbeddedStatement", CSharp.Statement.Null);
+		public readonly static Role<EntityDeclaration> TypeMemberRole = new Role<EntityDeclaration> ("TypeMember");
+		
+
+		//			public static readonly TokenRole Keyword = new TokenRole ("Keyword", CSharpTokenNode.Null);
+//			public static readonly TokenRole InKeyword = new TokenRole ("InKeyword", CSharpTokenNode.Null);
+			
+		// some pre defined constants for most used punctuation
+		public static readonly TokenRole LPar = new TokenRole ("(");
+		public static readonly TokenRole RPar = new TokenRole (")");
+		public static readonly TokenRole LBracket = new TokenRole ("[");
+		public static readonly TokenRole RBracket = new TokenRole ("]");
+		public static readonly TokenRole LBrace = new TokenRole ("{");
+		public static readonly TokenRole RBrace = new TokenRole ("}");
+		public static readonly TokenRole LChevron = new TokenRole ("<");
+		public static readonly TokenRole RChevron = new TokenRole (">");
+		public static readonly TokenRole Comma = new TokenRole (",");
+		public static readonly TokenRole Dot = new TokenRole (".");
+		public static readonly TokenRole Semicolon = new TokenRole (";");
+		public static readonly TokenRole Assign = new TokenRole ("=");
+		public static readonly TokenRole Colon = new TokenRole (":");
+		public static readonly TokenRole DoubleColon = new TokenRole ("::");
+		public static readonly Role<Comment> Comment = new Role<Comment> ("Comment");
+		public static readonly Role<NewLineNode> NewLine = new Role<NewLineNode> ("NewLine");
+		public static readonly Role<WhitespaceNode> Whitespace = new Role<WhitespaceNode> ("Whitespace");
+		public static readonly Role<TextNode> Text = new Role<TextNode> ("Text");
+		public static readonly Role<PreProcessorDirective> PreProcessorDirective = new Role<PreProcessorDirective> ("PreProcessorDirective");
+		public static readonly Role<ErrorNode> Error = new Role<ErrorNode> ("Error");
+			
+		public readonly static Role<AstType> BaseType = new Role<AstType> ("BaseType", AstType.Null);
+
+		public static readonly Role<Attribute> Attribute = new Role<Attribute> ("Attribute");
+		public static readonly Role<CSharpTokenNode> AttributeTargetRole = new Role<CSharpTokenNode> ("AttributeTarget", CSharpTokenNode.Null);
+
+		public readonly static TokenRole WhereKeyword = new TokenRole ("where");
+		public readonly static Role<SimpleType> ConstraintTypeParameter = new Role<SimpleType> ("TypeParameter", SimpleType.Null);
+		public readonly static TokenRole DelegateKeyword = new TokenRole ("delegate");
+		public static readonly TokenRole ExternKeyword = new TokenRole ("extern");
+		public static readonly TokenRole AliasKeyword = new TokenRole ("alias");
+		public static readonly TokenRole NamespaceKeyword = new TokenRole ("namespace");
+
+		public static readonly TokenRole EnumKeyword = new TokenRole ("enum");
+		public static readonly TokenRole InterfaceKeyword = new TokenRole ("interface");
+		public static readonly TokenRole StructKeyword = new TokenRole ("struct");
+		public static readonly TokenRole ClassKeyword = new TokenRole ("class");
+
+	}
+}
+

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/SimpleType.cs

@@ -47,7 +47,16 @@ namespace ICSharpCode.NRefactory.CSharp
 				}
 			}
 			
-			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return default (T);
+			}
+			
+			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 			{
 				return default (S);
 			}
@@ -100,7 +109,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole (Roles.Identifier, CSharp.Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole (Roles.Identifier, CSharp.Identifier.Create (value));
 			}
 		}
 		
@@ -117,7 +126,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildrenByRole (Roles.TypeArgument); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitSimpleType (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitSimpleType (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitSimpleType (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/BlockStatement.cs

@@ -45,7 +45,16 @@ namespace ICSharpCode.NRefactory.CSharp
 				}
 			}
 			
-			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return default (T);
+			}
+
+			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 			{
 				return default (S);
 			}
@@ -76,7 +85,17 @@ namespace ICSharpCode.NRefactory.CSharp
 				get { return NodeType.Pattern; }
 			}
 			
-			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+				visitor.VisitPatternPlaceholder(this, child);
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return visitor.VisitPatternPlaceholder(this, child);
+			}
+			
+			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 			{
 				return visitor.VisitPatternPlaceholder(this, child, data);
 			}
@@ -105,7 +124,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.RBrace); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitBlockStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitBlockStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitBlockStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/BreakStatement.cs

@@ -31,11 +31,27 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class BreakStatement : Statement
 	{
+		public static readonly TokenRole BreakKeywordRole = new TokenRole ("break");
+		
+		public CSharpTokenNode BreakToken {
+			get { return GetChildByRole (BreakKeywordRole); }
+		}
+		
 		public CSharpTokenNode SemicolonToken {
 			get { return GetChildByRole (Roles.Semicolon); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitBreakStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitBreakStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitBreakStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/CheckedStatement.cs

@@ -31,8 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class CheckedStatement : Statement
 	{
+		public static readonly TokenRole CheckedKeywordRole = new TokenRole ("checked");
+		
 		public CSharpTokenNode CheckedToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (CheckedKeywordRole); }
 		}
 		
 		public BlockStatement Body {
@@ -49,7 +51,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (body, Roles.Body);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitCheckedStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitCheckedStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitCheckedStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/ContinueStatement.cs

@@ -31,11 +31,27 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class ContinueStatement : Statement
 	{
+		public static readonly TokenRole ContinueKeywordRole = new TokenRole ("continue");
+		
+		public CSharpTokenNode ContinueToken {
+			get { return GetChildByRole (ContinueKeywordRole); }
+		}
+		
 		public CSharpTokenNode SemicolonToken {
 			get { return GetChildByRole (Roles.Semicolon); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitContinueStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitContinueStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitContinueStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/DoWhileStatement.cs

@@ -31,8 +31,8 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class DoWhileStatement : Statement
 	{
-		public static readonly Role<CSharpTokenNode> DoKeywordRole = new Role<CSharpTokenNode>("DoKeyword", CSharpTokenNode.Null);
-		public static readonly Role<CSharpTokenNode> WhileKeywordRole = new Role<CSharpTokenNode>("WhileKeyword", CSharpTokenNode.Null);
+		public static readonly TokenRole DoKeywordRole = new TokenRole ("do");
+		public static readonly TokenRole WhileKeywordRole = new TokenRole ("while");
 		
 		public CSharpTokenNode DoToken {
 			get { return GetChildByRole (DoKeywordRole); }
@@ -64,7 +64,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.Semicolon); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitDoWhileStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitDoWhileStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitDoWhileStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/EmptyStatement.cs

@@ -29,7 +29,7 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// <summary>
 	/// ;
 	/// </summary>
-	public class EmptyStatement : Statement, IRelocatable
+	public class EmptyStatement : Statement
 	{
 		public TextLocation Location {
 			get;
@@ -48,14 +48,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		#region IRelocationable implementation
-		void IRelocatable.SetStartLocation (TextLocation startLocation)
+		public override void AcceptVisitor (IAstVisitor visitor)
 		{
-			this.Location = startLocation;
+			visitor.VisitEmptyStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitEmptyStatement (this);
 		}
-		#endregion
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitEmptyStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/ExpressionStatement.cs

@@ -40,7 +40,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.Semicolon); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitExpressionStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitExpressionStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitExpressionStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/FixedStatement.cs

@@ -33,8 +33,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class FixedStatement : Statement
 	{
+		public static readonly TokenRole FixedKeywordRole = new TokenRole ("fixed");
+		
 		public CSharpTokenNode FixedToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (FixedKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -59,7 +61,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.EmbeddedStatement, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitFixedStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitFixedStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitFixedStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/ForStatement.cs

@@ -33,11 +33,12 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class ForStatement : Statement
 	{
+		public static readonly TokenRole ForKeywordRole = new TokenRole ("for");
 		public readonly static Role<Statement> InitializerRole = new Role<Statement>("Initializer", Statement.Null);
 		public readonly static Role<Statement> IteratorRole = new Role<Statement>("Iterator", Statement.Null);
 		
 		public CSharpTokenNode ForToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (ForKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -71,7 +72,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.EmbeddedStatement, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitForStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitForStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitForStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/ForeachStatement.cs

@@ -31,8 +31,11 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class ForeachStatement : Statement
 	{
+		public static readonly TokenRole ForeachKeywordRole = new TokenRole ("foreach");
+		public static readonly TokenRole InKeywordRole = new TokenRole ("in");
+		
 		public CSharpTokenNode ForeachToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (ForeachKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -49,7 +52,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole(Roles.Identifier, Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(Roles.Identifier, Identifier.Create (value));
 			}
 		}
 		
@@ -63,7 +66,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public CSharpTokenNode InToken {
-			get { return GetChildByRole (Roles.InKeyword); }
+			get { return GetChildByRole (InKeywordRole); }
 		}
 		
 		public Expression InExpression {
@@ -80,7 +83,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.EmbeddedStatement, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitForeachStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitForeachStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitForeachStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/GotoStatement.cs

@@ -31,6 +31,8 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class GotoStatement : Statement
 	{
+		public static readonly TokenRole GotoKeywordRole = new TokenRole ("goto");
+		
 		public GotoStatement ()
 		{
 		}
@@ -41,7 +43,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public CSharpTokenNode GotoToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (GotoKeywordRole); }
 		}
 		
 		public string Label {
@@ -52,7 +54,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				if (string.IsNullOrEmpty(value))
 					SetChildByRole(Roles.Identifier, null);
 				else
-					SetChildByRole(Roles.Identifier, Identifier.Create (value, TextLocation.Empty));
+					SetChildByRole(Roles.Identifier, Identifier.Create (value));
 			}
 		}
 		
@@ -60,7 +62,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.Semicolon); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitGotoStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitGotoStatement (this);
+		}
+
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitGotoStatement (this, data);
 		}
@@ -77,10 +89,11 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class GotoCaseStatement : Statement
 	{
-		public static readonly Role<CSharpTokenNode> CaseKeywordRole = new Role<CSharpTokenNode>("CaseKeyword", CSharpTokenNode.Null);
+		public static readonly TokenRole GotoKeywordRole = new TokenRole ("goto");
+		public static readonly TokenRole CaseKeywordRole = new TokenRole ("case");
 		
 		public CSharpTokenNode GotoToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (GotoKeywordRole); }
 		}
 		
 		public CSharpTokenNode CaseToken {
@@ -99,7 +112,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.Semicolon); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitGotoCaseStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitGotoCaseStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitGotoCaseStatement (this, data);
 		}
@@ -116,10 +139,11 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class GotoDefaultStatement : Statement
 	{
-		public static readonly Role<CSharpTokenNode> DefaultKeywordRole = new Role<CSharpTokenNode>("DefaultKeyword", CSharpTokenNode.Null);
+		public static readonly TokenRole GotoKeywordRole = new TokenRole ("goto");
+		public static readonly TokenRole DefaultKeywordRole = new TokenRole ("default");
 		
 		public CSharpTokenNode GotoToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (GotoKeywordRole); }
 		}
 		
 		public CSharpTokenNode DefaultToken {
@@ -130,7 +154,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.Semicolon); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitGotoDefaultStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitGotoDefaultStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitGotoDefaultStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/IfElseStatement.cs

@@ -31,11 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class IfElseStatement : Statement
 	{
-		public readonly static Role<CSharpTokenNode> IfKeywordRole = Roles.Keyword;
+		public readonly static TokenRole IfKeywordRole = new TokenRole ("if");
 		public readonly static Role<Expression> ConditionRole = Roles.Condition;
-		public readonly static Role<CSharpTokenNode> QuestionMarkRole = new Role<CSharpTokenNode>("QuestionMark", CSharpTokenNode.Null);
 		public readonly static Role<Statement> TrueRole = new Role<Statement>("True", Statement.Null);
-		public readonly static Role<CSharpTokenNode> ElseKeywordRole = new Role<CSharpTokenNode>("ElseKeyword", CSharpTokenNode.Null);
+		public readonly static TokenRole ElseKeywordRole = new TokenRole ("else");
 		public readonly static Role<Statement> FalseRole = new Role<Statement>("False", Statement.Null);
 		
 		public CSharpTokenNode IfToken {
@@ -69,7 +68,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (FalseRole, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitIfElseStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitIfElseStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitIfElseStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/LabelStatement.cs

@@ -36,15 +36,30 @@ namespace ICSharpCode.NRefactory.CSharp
 				return GetChildByRole (Roles.Identifier).Name;
 			}
 			set {
-				SetChildByRole(Roles.Identifier, Identifier.Create (value, TextLocation.Empty));
+				SetChildByRole(Roles.Identifier, Identifier.Create (value));
 			}
 		}
 		
+		public Identifier LabelToken {
+			get { return GetChildByRole (Roles.Identifier); }
+			set { SetChildByRole (Roles.Identifier, value); }
+		}
+
 		public CSharpTokenNode Colon {
 			get { return GetChildByRole (Roles.Colon); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitLabelStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitLabelStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitLabelStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/LockStatement.cs

@@ -31,8 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class LockStatement : Statement
 	{
+		public static readonly TokenRole LockKeywordRole = new TokenRole ("lock");
+		
 		public CSharpTokenNode LockToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (LockKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -53,7 +55,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.EmbeddedStatement, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitLockStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitLockStatement (this);
+		}
+
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitLockStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/ReturnStatement.cs

@@ -31,8 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class ReturnStatement : Statement
 	{
+		public static readonly TokenRole ReturnKeywordRole = new TokenRole ("return");
+
 		public CSharpTokenNode ReturnToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (ReturnKeywordRole); }
 		}
 		
 		public Expression Expression {
@@ -53,7 +55,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (returnExpression, Roles.Expression);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitReturnStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitReturnStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitReturnStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/Statement.cs

@@ -25,7 +25,16 @@ namespace ICSharpCode.NRefactory.CSharp
 				}
 			}
 			
-			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return default (T);
+			}
+
+			public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 			{
 				return default (S);
 			}
@@ -56,7 +65,17 @@ namespace ICSharpCode.NRefactory.CSharp
 				get { return NodeType.Pattern; }
 			}
 			
-			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+				visitor.VisitPatternPlaceholder(this, child);
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return visitor.VisitPatternPlaceholder(this, child);
+			}
+
+			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 			{
 				return visitor.VisitPatternPlaceholder(this, child, data);
 			}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/SwitchStatement.cs

@@ -34,10 +34,11 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class SwitchStatement : Statement
 	{
+		public static readonly TokenRole SwitchKeywordRole = new TokenRole ("switch");
 		public static readonly Role<SwitchSection> SwitchSectionRole = new Role<SwitchSection>("SwitchSection");
 		
 		public CSharpTokenNode SwitchToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (SwitchKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -65,7 +66,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.RBrace); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitSwitchStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitSwitchStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitSwitchStatement (this, data);
 		}
@@ -98,7 +109,17 @@ namespace ICSharpCode.NRefactory.CSharp
 				get { return NodeType.Pattern; }
 			}
 			
-			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+				visitor.VisitPatternPlaceholder(this, child);
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return visitor.VisitPatternPlaceholder(this, child);
+			}
+			
+			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 			{
 				return visitor.VisitPatternPlaceholder(this, child, data);
 			}
@@ -131,7 +152,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildrenByRole (Roles.EmbeddedStatement); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitSwitchSection (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitSwitchSection (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitSwitchSection (this, data);
 		}
@@ -145,6 +176,9 @@ namespace ICSharpCode.NRefactory.CSharp
 	
 	public class CaseLabel : AstNode
 	{
+		public static readonly TokenRole CaseKeywordRole = new TokenRole ("case");
+		public static readonly TokenRole DefaultKeywordRole = new TokenRole ("default");
+		
 		public override NodeType NodeType {
 			get {
 				return NodeType.Unknown;
@@ -158,7 +192,11 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.Expression); }
 			set { SetChildByRole (Roles.Expression, value); }
 		}
-		
+
+		public CSharpTokenNode ColonToken {
+			get { return GetChildByRole (Roles.Colon); }
+		}
+
 		public CaseLabel ()
 		{
 		}
@@ -168,7 +206,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			this.Expression = expression;
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitCaseLabel (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitCaseLabel (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitCaseLabel (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/ThrowStatement.cs

@@ -31,8 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class ThrowStatement : Statement
 	{
+		public static readonly TokenRole ThrowKeywordRole = new TokenRole ("throw");
+		
 		public CSharpTokenNode ThrowToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (ThrowKeywordRole); }
 		}
 		
 		public Expression Expression {
@@ -53,7 +55,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (expression, Roles.Expression);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitThrowStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitThrowStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitThrowStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/TryCatchStatement.cs

@@ -34,10 +34,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class TryCatchStatement : Statement
 	{
-		public static readonly Role<CSharpTokenNode> TryKeywordRole = new Role<CSharpTokenNode>("TryKeyword", CSharpTokenNode.Null);
+		public static readonly TokenRole TryKeywordRole = new TokenRole ("try");
 		public static readonly Role<BlockStatement> TryBlockRole = new Role<BlockStatement>("TryBlock", BlockStatement.Null);
 		public static readonly Role<CatchClause> CatchClauseRole = new Role<CatchClause>("CatchClause");
-		public static readonly Role<CSharpTokenNode> FinallyKeywordRole = new Role<CSharpTokenNode>("FinallyKeyword", CSharpTokenNode.Null);
+		public static readonly TokenRole FinallyKeywordRole = new TokenRole ("finally");
 		public static readonly Role<BlockStatement> FinallyBlockRole = new Role<BlockStatement>("FinallyBlock", BlockStatement.Null);
 		
 		public CSharpTokenNode TryToken {
@@ -62,7 +62,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (FinallyBlockRole, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitTryCatchStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitTryCatchStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitTryCatchStatement (this, data);
 		}
@@ -79,6 +89,8 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class CatchClause : AstNode
 	{
+		public static readonly TokenRole CatchKeywordRole = new TokenRole ("catch");
+		
 		#region PatternPlaceholder
 		public static implicit operator CatchClause(PatternMatching.Pattern pattern)
 		{
@@ -98,7 +110,17 @@ namespace ICSharpCode.NRefactory.CSharp
 				get { return NodeType.Pattern; }
 			}
 			
-			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data = default(T))
+			public override void AcceptVisitor (IAstVisitor visitor)
+			{
+				visitor.VisitPatternPlaceholder(this, child);
+			}
+				
+			public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+			{
+				return visitor.VisitPatternPlaceholder(this, child);
+			}
+
+			public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
 			{
 				return visitor.VisitPatternPlaceholder(this, child, data);
 			}
@@ -122,7 +144,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public CSharpTokenNode CatchToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (CatchKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -140,7 +162,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				if (string.IsNullOrEmpty(value))
 					SetChildByRole (Roles.Identifier, null);
 				else
-					SetChildByRole (Roles.Identifier, Identifier.Create (value, TextLocation.Empty));
+					SetChildByRole (Roles.Identifier, Identifier.Create (value));
 			}
 		}
 		
@@ -162,7 +184,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Body, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitCatchClause (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitCatchClause (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitCatchClause (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/UncheckedStatement.cs

@@ -31,8 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class UncheckedStatement : Statement
 	{
+		public static readonly TokenRole UncheckedKeywordRole = new TokenRole ("unchecked");
+		
 		public CSharpTokenNode UncheckedToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (UncheckedKeywordRole); }
 		}
 		
 		public BlockStatement Body {
@@ -49,7 +51,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			AddChild (body, Roles.Body);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitUncheckedStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitUncheckedStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitUncheckedStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/UnsafeStatement.cs

@@ -31,8 +31,10 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class UnsafeStatement : Statement
 	{
+		public static readonly TokenRole UnsafeKeywordRole = new TokenRole ("unsafe");
+		
 		public CSharpTokenNode UnsafeToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (UnsafeKeywordRole); }
 		}
 		
 		public BlockStatement Body {
@@ -40,7 +42,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Body, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitUnsafeStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitUnsafeStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitUnsafeStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/UsingStatement.cs

@@ -31,10 +31,11 @@ namespace ICSharpCode.NRefactory.CSharp
 	/// </summary>
 	public class UsingStatement : Statement
 	{
+		public static readonly TokenRole UsingKeywordRole = new TokenRole ("using");
 		public static readonly Role<AstNode> ResourceAcquisitionRole = new Role<AstNode>("ResourceAcquisition", AstNode.Null);
 		
 		public CSharpTokenNode UsingToken {
-			get { return GetChildByRole (Roles.Keyword); }
+			get { return GetChildByRole (UsingKeywordRole); }
 		}
 		
 		public CSharpTokenNode LParToken {
@@ -58,7 +59,17 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.EmbeddedStatement, value); }
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitUsingStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitUsingStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitUsingStatement (this, data);
 		}

NRefactory/ICSharpCode.NRefactory.CSharp/Ast/Statements/VariableDeclarationStatement.cs

@@ -31,7 +31,7 @@ namespace ICSharpCode.NRefactory.CSharp
 {
 	public class VariableDeclarationStatement : Statement
 	{
-		public static readonly Role<CSharpModifierToken> ModifierRole = AttributedNode.ModifierRole;
+		public static readonly Role<CSharpModifierToken> ModifierRole = EntityDeclaration.ModifierRole;
 		
 		public VariableDeclarationStatement()
 		{
@@ -44,8 +44,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		
 		public Modifiers Modifiers {
-			get { return AttributedNode.GetModifiers(this); }
-			set { AttributedNode.SetModifiers(this, value); }
+			get { return EntityDeclaration.GetModifiers(this); }
+			set { EntityDeclaration.SetModifiers(this, value); }
 		}
 		
 		public AstType Type {
@@ -63,10 +63,20 @@ namespace ICSharpCode.NRefactory.CSharp
 		
 		public VariableInitializer GetVariable (string name)
 		{
-			return Variables.FirstOrDefault (vi => vi.Name == name);
+			return Variables.FirstOrNullObject (vi => vi.Name == name);
 		}
 		
-		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data = default(T))
+		public override void AcceptVisitor (IAstVisitor visitor)
+		{
+			visitor.VisitVariableDeclarationStatement (this);
+		}
+			
+		public override T AcceptVisitor<T> (IAstVisitor<T> visitor)
+		{
+			return visitor.VisitVariableDeclarationStatement (this);
+		}
+		
+		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)
 		{
 			return visitor.VisitVariableDeclarationStatement (this, data);
 		}