NRefactory: remove collection setters from AST; expose AstNodeCollection<T> instead.

ICSharpCode.NRefactory/CSharp/Ast/AstNode.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // AstNode.cs
 //
 // Author:
@@ -164,16 +164,9 @@ namespace ICSharpCode.NRefactory.CSharp
 			return role.NullObject;
 		}
 		
-		public IEnumerable<T> GetChildrenByRole<T>(Role<T> role) where T : AstNode
+		public AstNodeCollection<T> GetChildrenByRole<T>(Role<T> role) where T : AstNode
 		{
-			AstNode next;
+			return new AstNodeCollection<T>(this, role);
-			for (AstNode cur = firstChild; cur != null; cur = next) {
-				// Remember next before yielding cur.
-				// This allows removing/replacing nodes while iterating through the list.
-				next = cur.nextSibling;
-				if (cur.role == role)
-					yield return (T)cur;
-			}
 		}
 		
 		protected void SetChildByRole<T>(Role<T> role, T newChild) where T : AstNode
@@ -185,24 +178,6 @@ namespace ICSharpCode.NRefactory.CSharp
 				oldChild.ReplaceWith(newChild);
 		}
 		
-		protected void SetChildrenByRole<T>(Role<T> role, IEnumerable<T> newChildren) where T : AstNode
-		{
-			// Evaluate 'newChildren' first, since it might change when we remove the old children
-			// Example: SetChildren(role, GetChildrenByRole(role));
-			if (newChildren != null)
-				newChildren = newChildren.ToList();
-			
-			// remove old children
-			foreach (AstNode node in GetChildrenByRole(role))
-				node.Remove();
-			// add new children
-			if (newChildren != null) {
-				foreach (T node in newChildren) {
-					AddChild(node, role);
-				}
-			}
-		}
-		
 		public void AddChild<T>(T child, Role<T> role) where T : AstNode
 		{
 			if (role == null)

ICSharpCode.NRefactory/CSharp/Ast/AstNodeCollection.cs

@@ -0,0 +1,156 @@
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under MIT X11 license (for details please see \doc\license.txt)
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace ICSharpCode.NRefactory.CSharp
+{
+	/// <summary>
+	/// Represents the children of an AstNode that have a specific role.
+	/// </summary>
+	public struct AstNodeCollection<T> : ICollection<T> where T : AstNode
+	{
+		readonly AstNode node;
+		readonly Role<T> role;
+		
+		public AstNodeCollection(AstNode node, Role<T> role)
+		{
+			if (node == null)
+				throw new ArgumentNullException("node");
+			if (role == null)
+				throw new ArgumentNullException("role");
+			this.node = node;
+			this.role = role;
+		}
+		
+		public int Count {
+			get {
+				var e = GetEnumerator();
+				int count = 0;
+				while (e.MoveNext())
+					count++;
+				return count;
+			}
+		}
+		
+		public void Add(T element)
+		{
+			node.AddChild(element, role);
+		}
+		
+		public void AddRange(IEnumerable<T> nodes)
+		{
+			// Evaluate 'nodes' first, since it might change when we add the new children
+			// Example: collection.AddRange(collection);
+			if (nodes != null) {
+				foreach (T node in nodes.ToList())
+					Add(node);
+			}
+		}
+		
+		public void AddRange(T[] nodes)
+		{
+			// Fast overload for arrays - we don't need to create a copy
+			if (nodes != null) {
+				foreach (T node in nodes)
+					Add(node);
+			}
+		}
+		
+		public void ReplaceWith(IEnumerable<T> nodes)
+		{
+			// Evaluate 'nodes' first, since it might change when we call Clear()
+			// Example: collection.ReplaceWith(collection);
+			if (nodes != null)
+				nodes = nodes.ToList();
+			Clear();
+			foreach (T node in nodes)
+				Add(node);
+		}
+		
+		public void MoveTo(ICollection<T> targetCollection)
+		{
+			foreach (T node in this) {
+				node.Remove();
+				targetCollection.Add(node);
+			}
+		}
+		
+		public bool Contains(T element)
+		{
+			return element != null && element.Parent == node && element.Role == role;
+		}
+		
+		public bool Remove(T element)
+		{
+			if (Contains(element)) {
+				element.Remove();
+				return true;
+			} else {
+				return false;
+			}
+		}
+		
+		public void CopyTo(T[] array, int arrayIndex)
+		{
+			foreach (T item in this)
+				array[arrayIndex++] = item;
+		}
+		
+		public void Clear()
+		{
+			foreach (T item in this)
+				item.Remove();
+		}
+		
+		bool ICollection<T>.IsReadOnly {
+			get { return false; }
+		}
+		
+		public IEnumerator<T> GetEnumerator()
+		{
+			AstNode next;
+			for (AstNode cur = node.FirstChild; cur != null; cur = next) {
+				// Remember next before yielding cur.
+				// This allows removing/replacing nodes while iterating through the list.
+				next = cur.NextSibling;
+				if (cur.Role == role)
+					yield return (T)cur;
+			}
+		}
+		
+		IEnumerator IEnumerable.GetEnumerator()
+		{
+			return GetEnumerator();
+		}
+		
+		#region Equals and GetHashCode implementation
+		public override bool Equals(object obj)
+		{
+			if (obj is AstNodeCollection<T>) {
+				return ((AstNodeCollection<T>)obj) == this;
+			} else {
+				return false;
+			}
+		}
+		
+		public override int GetHashCode()
+		{
+			return node.GetHashCode() ^ role.GetHashCode();
+		}
+		
+		public static bool operator ==(AstNodeCollection<T> left, AstNodeCollection<T> right)
+		{
+			return left.role == right.role && left.node == right.node;
+		}
+		
+		public static bool operator !=(AstNodeCollection<T> left, AstNodeCollection<T> right)
+		{
+			return !(left.role == right.role && left.node == right.node);
+		}
+		#endregion
+	}
+}

ICSharpCode.NRefactory/CSharp/Ast/ComposedType.cs

@@ -67,9 +67,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		public IEnumerable<ArraySpecifier> ArraySpecifiers {
+		public AstNodeCollection<ArraySpecifier> ArraySpecifiers {
 			get { return GetChildrenByRole (ArraySpecifierRole); }
-			set { SetChildrenByRole (ArraySpecifierRole, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

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

@@ -1,4 +1,4 @@
-// 
+// 
 // AnonymousMethodExpression.cs
 //
 // Author:
@@ -47,9 +47,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LPar); }
 		}
 		
-		public IEnumerable<ParameterDeclaration> Parameters {
+		public AstNodeCollection<ParameterDeclaration> Parameters {
 			get { return GetChildrenByRole (Roles.Parameter); }
-			set { SetChildrenByRole (Roles.Parameter, value); }
 		}
 		
 		public CSharpTokenNode RParToken {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // ArgListExpression.cs
 //  
 // Author:
@@ -45,9 +45,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LPar); }
 		}
 		
-		public IEnumerable<Expression> Arguments {
+		public AstNodeCollection<Expression> Arguments {
 			get { return GetChildrenByRole(Roles.Argument); }
-			set { SetChildrenByRole(Roles.Argument, value); }
 		}
 		
 		public CSharpTokenNode RParToken {

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

@@ -16,18 +16,16 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Type, value); }
 		}
 		
-		public IEnumerable<Expression> Arguments {
+		public AstNodeCollection<Expression> Arguments {
 			get { return GetChildrenByRole (Roles.Argument); }
-			set { SetChildrenByRole (Roles.Argument, value); }
 		}
 		
 		/// <summary>
 		/// Gets additional array ranks (those without size info).
 		/// Empty for "new int[5,1]"; will contain a single element for "new int[5][]".
 		/// </summary>
-		public IEnumerable<ArraySpecifier> AdditionalArraySpecifiers {
+		public AstNodeCollection<ArraySpecifier> AdditionalArraySpecifiers {
 			get { return GetChildrenByRole(AdditionalArraySpecifierRole); }
-			set { SetChildrenByRole (AdditionalArraySpecifierRole, value); }
 		}
 		
 		public ArrayInitializerExpression Initializer {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // ArrayInitializerExpression.cs
 //
 // Author:
@@ -55,9 +55,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LBrace); }
 		}
 		
-		public IEnumerable<Expression> Elements {
+		public AstNodeCollection<Expression> Elements {
 			get { return GetChildrenByRole(Roles.Expression); }
-			set { SetChildrenByRole(Roles.Expression, value); }
 		}
 		
 		public CSharpTokenNode RBraceToken {

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

@@ -66,7 +66,10 @@ namespace ICSharpCode.NRefactory.CSharp
 		/// </summary>
 		public IndexerExpression Indexer(IEnumerable<Expression> arguments)
 		{
-			return new IndexerExpression { Target = this, Arguments = arguments };
+			IndexerExpression expr = new IndexerExpression();
+			expr.Target = this;
+			expr.Arguments.AddRange(arguments);
+			return expr;
 		}
 		
 		/// <summary>
@@ -74,7 +77,10 @@ namespace ICSharpCode.NRefactory.CSharp
 		/// </summary>
 		public IndexerExpression Indexer(params Expression[] arguments)
 		{
-			return new IndexerExpression { Target = this, Arguments = arguments };
+			IndexerExpression expr = new IndexerExpression();
+			expr.Target = this;
+			expr.Arguments.AddRange(arguments);
+			return expr;
 		}
 		
 		/// <summary>
@@ -98,14 +104,14 @@ namespace ICSharpCode.NRefactory.CSharp
 		/// </summary>
 		public InvocationExpression Invoke(string methodName, IEnumerable<AstType> typeArguments, IEnumerable<Expression> arguments)
 		{
-			return new InvocationExpression {
+			InvocationExpression ie = new InvocationExpression();
-				Target = new MemberReferenceExpression {
+			MemberReferenceExpression mre = new MemberReferenceExpression();
-					Target = this,
+			mre.Target = this;
-					MemberName = methodName,
+			mre.MemberName = methodName;
-					TypeArguments = typeArguments
+			mre.TypeArguments.AddRange(typeArguments);
-				},
+			ie.Target = mre;
-				Arguments = arguments
+			ie.Arguments.AddRange(arguments);
-			};
+			return ie;
 		}
 		
 		/// <summary>
@@ -113,10 +119,10 @@ namespace ICSharpCode.NRefactory.CSharp
 		/// </summary>
 		public InvocationExpression Invoke(IEnumerable<Expression> arguments)
 		{
-			return new InvocationExpression {
+			InvocationExpression ie = new InvocationExpression();
-				Target = this,
+			ie.Target = this;
-				Arguments = arguments
+			ie.Arguments.AddRange(arguments);
-			};
+			return ie;
 		}
 		
 		/// <summary>
@@ -124,7 +130,10 @@ namespace ICSharpCode.NRefactory.CSharp
 		/// </summary>
 		public InvocationExpression Invoke(params Expression[] arguments)
 		{
-			return Invoke(arguments.AsEnumerable());
+			InvocationExpression ie = new InvocationExpression();
+			ie.Target = this;
+			ie.Arguments.AddRange(arguments);
+			return ie;
 		}
 		
 		public CastExpression CastTo(AstType type)

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

@@ -1,4 +1,4 @@
-// 
+// 
 // IdentifierExpression.cs
 //  
 // Author:
@@ -56,9 +56,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		public IEnumerable<AstType> TypeArguments {
+		public AstNodeCollection<AstType> TypeArguments {
 			get { return GetChildrenByRole (Roles.TypeArgument); }
-			set { SetChildrenByRole (Roles.TypeArgument, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

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

@@ -1,4 +1,4 @@
-// 
+// 
 // IndexerExpression.cs
 //  
 // Author:
@@ -42,9 +42,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LBracket); }
 		}
 		
-		public IEnumerable<Expression> Arguments {
+		public AstNodeCollection<Expression> Arguments {
 			get { return GetChildrenByRole<Expression>(Roles.Argument); }
-			set { SetChildrenByRole(Roles.Argument, value); }
 		}
 		
 		public CSharpTokenNode RBracketToken {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // InvocationExpression.cs
 //
 // Author:
@@ -42,9 +42,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LPar); }
 		}
 		
-		public IEnumerable<Expression> Arguments {
+		public AstNodeCollection<Expression> Arguments {
 			get { return GetChildrenByRole<Expression>(Roles.Argument); }
-			set { SetChildrenByRole(Roles.Argument, value); }
 		}
 		
 		public CSharpTokenNode RParToken {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // LambdaExpression.cs
 //  
 // Author:
@@ -36,9 +36,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		public readonly static Role<CSharpTokenNode> ArrowRole = new Role<CSharpTokenNode>("Arrow", CSharpTokenNode.Null);
 		public static readonly Role<AstNode> BodyRole = new Role<AstNode>("Body", AstNode.Null);
 		
-		public IEnumerable<ParameterDeclaration> Parameters { 
+		public AstNodeCollection<ParameterDeclaration> Parameters { 
 			get { return GetChildrenByRole (Roles.Parameter); }
-			set { SetChildrenByRole (Roles.Parameter, value); }
 		}
 		
 		public CSharpTokenNode ArrowToken {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // MemberReferenceExpression.cs
 //
 // Author:
@@ -51,9 +51,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LChevron); }
 		}
 		
-		public IEnumerable<AstType> TypeArguments {
+		public AstNodeCollection<AstType> TypeArguments {
 			get { return GetChildrenByRole (Roles.TypeArgument); }
-			set { SetChildrenByRole (Roles.TypeArgument, value); }
 		}
 		
 		public CSharpTokenNode RChevronToken {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // ObjectCreateExpression.cs
 //  
 // Author:
@@ -48,9 +48,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LPar); }
 		}
 		
-		public IEnumerable<Expression> Arguments {
+		public AstNodeCollection<Expression> Arguments {
 			get { return GetChildrenByRole (Roles.Argument); }
-			set { SetChildrenByRole (Roles.Argument, value); }
 		}
 		
 		public CSharpTokenNode RParToken {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // PointerReferenceExpression.cs
 //  
 // Author:
@@ -49,9 +49,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		public IEnumerable<AstType> TypeArguments {
+		public AstNodeCollection<AstType> TypeArguments {
 			get { return GetChildrenByRole (Roles.TypeArgument); }
-			set { SetChildrenByRole (Roles.TypeArgument, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

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

@@ -28,9 +28,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		}
 		#endregion
 		
-		public IEnumerable<QueryClause> Clauses {
+		public AstNodeCollection<QueryClause> Clauses {
 			get { return GetChildrenByRole(ClauseRole); }
-			set { SetChildrenByRole(ClauseRole, value); }
 		}
 		
 		public override S AcceptVisitor<T, S>(IAstVisitor<T, S> visitor, T data)
@@ -260,9 +259,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.Keyword); }
 		}
 		
-		public IEnumerable<QueryOrdering> Orderings {
+		public AstNodeCollection<QueryOrdering> Orderings {
 			get { return GetChildrenByRole (OrderingRole); }
-			set { SetChildrenByRole (OrderingRole, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

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

@@ -1,4 +1,4 @@
-// 
+// 
 // Attribute.cs
 //
 // Author:
@@ -44,9 +44,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Type, value); }
 		}
 		
-		public IEnumerable<Expression> Arguments {
+		public AstNodeCollection<Expression> Arguments {
 			get { return base.GetChildrenByRole (Roles.Argument); }
-			set { SetChildrenByRole (Roles.Argument, value); }
 		}
 
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

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

@@ -1,4 +1,4 @@
-// 
+// 
 // AttributeSection.cs
 //
 // Author:
@@ -49,9 +49,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			set;
 		}
 		
-		public IEnumerable<Attribute> Attributes {
+		public AstNodeCollection<Attribute> Attributes {
 			get { return base.GetChildrenByRole (AttributeRole); }
-			set { SetChildrenByRole (AttributeRole, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

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

@@ -1,4 +1,4 @@
-// 
+// 
 // Constraint.cs
 //
 // Author:
@@ -53,9 +53,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		
 		// TODO: what about new(), struct and class constraints?
 		
-		public IEnumerable<AstType> BaseTypes {
+		public AstNodeCollection<AstType> BaseTypes {
 			get { return GetChildrenByRole (BaseTypeRole); }
-			set { SetChildrenByRole (BaseTypeRole, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

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

@@ -1,4 +1,4 @@
-// 
+// 
 // DelegateDeclaration.cs
 //
 // Author:
@@ -54,27 +54,24 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Type, value); }
 		}
 		
-		public IEnumerable<TypeParameterDeclaration> TypeParameters {
+		public AstNodeCollection<TypeParameterDeclaration> TypeParameters {
 			get { return GetChildrenByRole (Roles.TypeParameter); }
-			set { SetChildrenByRole (Roles.TypeParameter, value); }
 		}
 		
 		public CSharpTokenNode LParToken {
 			get { return GetChildByRole (Roles.LPar); }
 		}
 		
-		public IEnumerable<ParameterDeclaration> Parameters {
+		public AstNodeCollection<ParameterDeclaration> Parameters {
 			get { return GetChildrenByRole (Roles.Parameter); }
-			set { SetChildrenByRole (Roles.Parameter, value); }
 		}
 		
 		public CSharpTokenNode RParToken {
 			get { return GetChildByRole (Roles.RPar); }
 		}
 		
-		public IEnumerable<Constraint> Constraints {
+		public AstNodeCollection<Constraint> Constraints {
 			get { return GetChildrenByRole (Roles.Constraint); }
-			set { SetChildrenByRole (Roles.Constraint, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

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

@@ -1,4 +1,4 @@
-// 
+// 
 // NamespaceDeclaration.cs
 //  
 // Author:
@@ -54,13 +54,12 @@ namespace ICSharpCode.NRefactory.CSharp
 				return builder.ToString ();
 			}
 			set {
-				SetChildrenByRole (Roles.Identifier, value.Split('.').Select(ident => new Identifier(ident, AstLocation.Empty)));
+				GetChildrenByRole(Roles.Identifier).ReplaceWith(value.Split('.').Select(ident => new Identifier(ident, AstLocation.Empty)));
 			}
 		}
 		
-		public IEnumerable<Identifier> Identifiers {
+		public AstNodeCollection<Identifier> Identifiers {
 			get { return GetChildrenByRole (Roles.Identifier); }
-			set { SetChildrenByRole (Roles.Identifier, value); }
 		}
 		
 		/// <summary>
@@ -79,9 +78,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LBrace); }
 		}
 		
-		public IEnumerable<AstNode> Members {
+		public AstNodeCollection<AstNode> Members {
 			get { return GetChildrenByRole(MemberRole); }
-			set { SetChildrenByRole(MemberRole, value); }
 		}
 		
 		public CSharpTokenNode RBraceToken {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // TypeDeclaration.cs
 //
 // Author:
@@ -59,28 +59,24 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		public IEnumerable<TypeParameterDeclaration> TypeParameters {
+		public AstNodeCollection<TypeParameterDeclaration> TypeParameters {
 			get { return GetChildrenByRole (Roles.TypeParameter); }
-			set { SetChildrenByRole (Roles.TypeParameter, value); }
 		}
 		
-		public IEnumerable<AstType> BaseTypes {
+		public AstNodeCollection<AstType> BaseTypes {
 			get { return GetChildrenByRole (BaseTypeRole); }
-			set { SetChildrenByRole (BaseTypeRole, value); }
 		}
 		
-		public IEnumerable<Constraint> Constraints {
+		public AstNodeCollection<Constraint> Constraints {
 			get { return GetChildrenByRole (Roles.Constraint); }
-			set { SetChildrenByRole (Roles.Constraint, value); }
 		}
 		
 		public CSharpTokenNode LBraceToken {
 			get { return GetChildByRole (Roles.LBrace); }
 		}
 		
-		public IEnumerable<AttributedNode> Members {
+		public AstNodeCollection<AttributedNode> Members {
 			get { return GetChildrenByRole (MemberRole); }
-			set { SetChildrenByRole (MemberRole, value); }
 		}
 		
 		public CSharpTokenNode RBraceToken {

ICSharpCode.NRefactory/CSharp/Ast/MemberType.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // FullTypeName.cs
 //
 // Author:
@@ -51,9 +51,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		public IEnumerable<AstType> TypeArguments {
+		public AstNodeCollection<AstType> TypeArguments {
 			get { return GetChildrenByRole (Roles.TypeArgument); }
-			set { SetChildrenByRole (Roles.TypeArgument, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

ICSharpCode.NRefactory/CSharp/Ast/SimpleType.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // FullTypeName.cs
 //
 // Author:
@@ -56,9 +56,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		public IEnumerable<AstType> TypeArguments {
+		public AstNodeCollection<AstType> TypeArguments {
 			get { return GetChildrenByRole (Roles.TypeArgument); }
-			set { SetChildrenByRole (Roles.TypeArgument, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

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

@@ -1,4 +1,4 @@
-// 
+// 
 // BlockStatement.cs
 //
 // Author:
@@ -56,9 +56,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LBrace); }
 		}
 		
-		public IEnumerable<Statement> Statements {
+		public AstNodeCollection<Statement> Statements {
 			get { return GetChildrenByRole (StatementRole); }
-			set { SetChildrenByRole (StatementRole, value); }
 		}
 		
 		public CSharpTokenNode RBraceToken {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // FixedStatement.cs
 //
 // Author:
@@ -46,9 +46,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Type, value); }
 		}
 		
-		public IEnumerable<VariableInitializer> Variables {
+		public AstNodeCollection<VariableInitializer> Variables {
 			get { return GetChildrenByRole (Roles.Variable); }
-			set { SetChildrenByRole (Roles.Variable, value); }
 		}
 		
 		public CSharpTokenNode RParToken {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // ForStatement.cs
 //  
 // Author:
@@ -49,9 +49,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		/// Note: this contains multiple statements for "for (a = 2, b = 1; a > b; a--)", but contains
 		/// only a single statement for "for (int a = 2, b = 1; a > b; a--)" (a single VariableDeclarationStatement with two variables)
 		/// </summary>
-		public IEnumerable<Statement> Initializers {
+		public AstNodeCollection<Statement> Initializers {
 			get { return GetChildrenByRole (InitializerRole); }
-			set { SetChildrenByRole (InitializerRole, value); }
 		}
 		
 		public Expression Condition {
@@ -59,9 +58,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Condition, value); }
 		}
 		
-		public IEnumerable<Statement> Iterators {
+		public AstNodeCollection<Statement> Iterators {
 			get { return GetChildrenByRole (IteratorRole); }
-			set { SetChildrenByRole (IteratorRole, value); }
 		}
 		
 		public CSharpTokenNode RParToken {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // SwitchStatement.cs
 //
 // Author:
@@ -57,9 +57,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LBrace); }
 		}
 		
-		public IEnumerable<SwitchSection> SwitchSections {
+		public AstNodeCollection<SwitchSection> SwitchSections {
 			get { return GetChildrenByRole (SwitchSectionRole); }
-			set { SetChildrenByRole (SwitchSectionRole, value); }
 		}
 		
 		public CSharpTokenNode RBraceToken {
@@ -82,14 +81,12 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		public IEnumerable<CaseLabel> CaseLabels {
+		public AstNodeCollection<CaseLabel> CaseLabels {
 			get { return GetChildrenByRole (CaseLabelRole); }
-			set { SetChildrenByRole (CaseLabelRole, value); }
 		}
 		
-		public IEnumerable<Statement> Statements {
+		public AstNodeCollection<Statement> Statements {
 			get { return GetChildrenByRole (Roles.EmbeddedStatement); }
-			set { SetChildrenByRole (Roles.EmbeddedStatement, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

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

@@ -1,4 +1,4 @@
-// 
+// 
 // TryCatchStatement.cs
 //
 // Author:
@@ -49,9 +49,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (TryBlockRole, value); }
 		}
 		
-		public IEnumerable<CatchClause> CatchClauses {
+		public AstNodeCollection<CatchClause> CatchClauses {
 			get { return GetChildrenByRole (CatchClauseRole); }
-			set { SetChildrenByRole (CatchClauseRole, value); }
 		}
 		
 		public CSharpTokenNode FinallyToken {

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

@@ -1,4 +1,4 @@
-// 
+// 
 // VariableDeclarationStatement.cs
 //  
 // Author:
@@ -33,6 +33,16 @@ namespace ICSharpCode.NRefactory.CSharp
 	{
 		public static readonly Role<CSharpModifierToken> ModifierRole = AttributedNode.ModifierRole;
 		
+		public VariableDeclarationStatement()
+		{
+		}
+		
+		public VariableDeclarationStatement(AstType type, string name, Expression initializer = null)
+		{
+			this.Type = type;
+			this.Variables.Add(new VariableInitializer(name, initializer));
+		}
+		
 		public Modifiers Modifiers {
 			get { return AttributedNode.GetModifiers(this); }
 			set { AttributedNode.SetModifiers(this, value); }
@@ -43,9 +53,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			set { SetChildByRole (Roles.Type, value); }
 		}
 		
-		public IEnumerable<VariableInitializer> Variables {
+		public AstNodeCollection<VariableInitializer> Variables {
 			get { return GetChildrenByRole (Roles.Variable); }
-			set { SetChildrenByRole (Roles.Variable, value); }
 		}
 		
 		public CSharpTokenNode SemicolonToken {

ICSharpCode.NRefactory/CSharp/Ast/TypeMembers/AttributedNode.cs

@@ -11,9 +11,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		public static readonly Role<AttributeSection> AttributeRole = new Role<AttributeSection>("Attribute");
 		public static readonly Role<CSharpModifierToken> ModifierRole = new Role<CSharpModifierToken>("Modifier");
 		
-		public IEnumerable<AttributeSection> Attributes {
+		public AstNodeCollection<AttributeSection> Attributes {
 			get { return base.GetChildrenByRole (AttributeRole); }
-			set { SetChildrenByRole (AttributeRole, value); }
 		}
 		
 		public Modifiers Modifiers {

ICSharpCode.NRefactory/CSharp/Ast/TypeMembers/ConstructorDeclaration.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // ConstructorDeclaration.cs
 //
 // Author:
@@ -37,9 +37,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LPar); }
 		}
 		
-		public IEnumerable<ParameterDeclaration> Parameters {
+		public AstNodeCollection<ParameterDeclaration> Parameters {
 			get { return GetChildrenByRole (Roles.Parameter); }
-			set { SetChildrenByRole (Roles.Parameter, value); }
 		}
 		
 		public CSharpTokenNode RParToken {
@@ -105,9 +104,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			set;
 		}
 		
-		public IEnumerable<Expression> Arguments {
+		public AstNodeCollection<Expression> Arguments {
 			get { return GetChildrenByRole (Roles.Argument); }
-			set { SetChildrenByRole (Roles.Argument, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

ICSharpCode.NRefactory/CSharp/Ast/TypeMembers/EventDeclaration.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // EventDeclaration.cs
 //
 // Author:
@@ -30,9 +30,8 @@ namespace ICSharpCode.NRefactory.CSharp
 {
 	public class EventDeclaration : MemberDeclaration
 	{
-		public IEnumerable<VariableInitializer> Variables {
+		public AstNodeCollection<VariableInitializer> Variables {
 			get { return GetChildrenByRole (Roles.Variable); }
-			set { SetChildrenByRole (Roles.Variable, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

ICSharpCode.NRefactory/CSharp/Ast/TypeMembers/FieldDeclaration.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // FieldDeclaration.cs
 //  
 // Author:
@@ -31,9 +31,8 @@ namespace ICSharpCode.NRefactory.CSharp
 {
 	public class FieldDeclaration : MemberDeclaration
 	{
-		public IEnumerable<VariableInitializer> Variables { 
+		public AstNodeCollection<VariableInitializer> Variables { 
 			get { return GetChildrenByRole (Roles.Variable); }
-			set { SetChildrenByRole (Roles.Variable, value); }
 		}
 		
 		public override S AcceptVisitor<T, S> (IAstVisitor<T, S> visitor, T data)

ICSharpCode.NRefactory/CSharp/Ast/TypeMembers/IndexerDeclaration.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // IndexerDeclaration.cs
 //  
 // Author:
@@ -35,9 +35,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LBracket); }
 		}
 		
-		public IEnumerable<ParameterDeclaration> Parameters { 
+		public AstNodeCollection<ParameterDeclaration> Parameters { 
 			get { return GetChildrenByRole (Roles.Parameter); }
-			set { SetChildrenByRole (Roles.Parameter, value); }
 		}
 		
 		public CSharpTokenNode RBracketToken {

ICSharpCode.NRefactory/CSharp/Ast/TypeMembers/MethodDeclaration.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // MethodDeclaration.cs
 //  
 // Author:
@@ -31,27 +31,24 @@ namespace ICSharpCode.NRefactory.CSharp
 {
 	public class MethodDeclaration : MemberDeclaration
 	{
-		public IEnumerable<TypeParameterDeclaration> TypeParameters {
+		public AstNodeCollection<TypeParameterDeclaration> TypeParameters {
 			get { return GetChildrenByRole (Roles.TypeParameter); }
-			set { SetChildrenByRole (Roles.TypeParameter, value); }
 		}
 		
 		public CSharpTokenNode LParToken {
 			get { return GetChildByRole (Roles.LPar); }
 		}
 		
-		public IEnumerable<ParameterDeclaration> Parameters { 
+		public AstNodeCollection<ParameterDeclaration> Parameters { 
 			get { return GetChildrenByRole (Roles.Parameter); }
-			set { SetChildrenByRole (Roles.Parameter, value); }
 		}
 		
 		public CSharpTokenNode RParToken {
 			get { return GetChildByRole (Roles.RPar); }
 		}
 		
-		public IEnumerable<Constraint> Constraints { 
+		public AstNodeCollection<Constraint> Constraints { 
 			get { return GetChildrenByRole (Roles.Constraint); }
-			set { SetChildrenByRole (Roles.Constraint, value); }
 		}
 		
 		public BlockStatement Body {

ICSharpCode.NRefactory/CSharp/Ast/TypeMembers/OperatorDeclaration.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // OperatorDeclaration.cs
 //  
 // Author:
@@ -80,9 +80,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return GetChildByRole (Roles.LPar); }
 		}
 		
-		public IEnumerable<ParameterDeclaration> Parameters { 
+		public AstNodeCollection<ParameterDeclaration> Parameters { 
 			get { return GetChildrenByRole (Roles.Parameter); }
-			set { SetChildrenByRole (Roles.Parameter, value); }
 		}
 		
 		public CSharpTokenNode RParToken {

ICSharpCode.NRefactory/CSharp/Ast/TypeMembers/ParameterDeclaration.cs

@@ -1,4 +1,4 @@
-// 
+// 
 // ParameterDeclarationExpression.cs
 //
 // Author:
@@ -49,9 +49,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 		
-		public IEnumerable<AttributeSection> Attributes {
+		public AstNodeCollection<AttributeSection> Attributes {
 			get { return GetChildrenByRole (AttributeRole); }
-			set { SetChildrenByRole (AttributeRole, value); }
 		}
 		
 		public ParameterModifier ParameterModifier {

ICSharpCode.NRefactory/CSharp/Parser/CSharpParser.cs

@@ -122,9 +122,7 @@ namespace ICSharpCode.NRefactory.CSharp
 						if (location != null)
 							spec.AddChild (new CSharpTokenNode (Convert (location[0]), 1), FieldDeclaration.Roles.RBracket);
 						
-						result.ArraySpecifiers = new ArraySpecifier[] {
+						result.ArraySpecifiers.Add(spec);
-							spec
-						};
 					}
 					return result;
 				}

ICSharpCode.NRefactory/ICSharpCode.NRefactory.csproj

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
   <PropertyGroup>
     <ProjectGuid>{3B2A5653-EC97-4001-BB9B-D90F1AF2C371}</ProjectGuid>
@@ -56,6 +56,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="CSharp\Ast\AstComparer.cs" />
+    <Compile Include="CSharp\Ast\AstNodeCollection.cs" />
     <Compile Include="CSharp\Ast\Expressions\TypeReferenceExpression.cs" />
     <Compile Include="CSharp\Ast\IAstVisitor.cs" />
     <Compile Include="CSharp\Ast\CompilationUnit.cs" />