source: branches/HiveProjectManagement/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Parser/CSharpParser.cs @ 15377

// 
// CSharpParser.cs
//
// Author:
//       Mike KrÃŒger <mkrueger@novell.com>
// 
// Copyright (c) 2009 Novell, Inc (http://www.novell.com)
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
using System;
using System.Linq;
using System.Collections.Generic;
using System.IO;
using ICSharpCode.NRefactory.Editor;
using Mono.CSharp;
using ICSharpCode.NRefactory.TypeSystem;

namespace ICSharpCode.NRefactory.CSharp
{
  public class CSharpParser
  {
    CompilerSettings compilerSettings;

    class ConversionVisitor : StructuralVisitor
    {
      SyntaxTree unit = new SyntaxTree();
      internal bool convertTypeSystemMode;

      public SyntaxTree Unit {
        get {
          return unit;
        }
        set {
          unit = value;
        }
      }

      public LocationsBag LocationsBag {
        get;
        private set;
      }

      public ConversionVisitor(bool convertTypeSystemMode, LocationsBag locationsBag)
      {
        this.convertTypeSystemMode = convertTypeSystemMode;
        this.LocationsBag = locationsBag;
      }

      public static TextLocation Convert(Location loc)
      {
        return new TextLocation(loc.Row, loc.Column);
      }

      public override void Visit(ModuleContainer mc)
      {
        bool first = true;
        foreach (var container in mc.Containers) {
          var nspace = container as NamespaceContainer;
          if (nspace == null) {
            container.Accept(this);
            continue;
          }
          NamespaceDeclaration nDecl = null;
          var loc = LocationsBag.GetLocations(nspace);
          
          if (nspace.NS != null && !string.IsNullOrEmpty(nspace.NS.Name)) {
            nDecl = new NamespaceDeclaration();
            if (loc != null) {
              nDecl.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.NamespaceKeyword), Roles.NamespaceKeyword);
            }
            nDecl.AddChild(ConvertNamespaceName(nspace.RealMemberName), NamespaceDeclaration.NamespaceNameRole);
            if (loc != null && loc.Count > 1) {
              nDecl.AddChild(new CSharpTokenNode(Convert(loc [1]), Roles.LBrace), Roles.LBrace);
            }
            AddToNamespace(nDecl);
            namespaceStack.Push(nDecl);
          }
          
          if (nspace.Usings != null) {
            foreach (var us in nspace.Usings) {
              us.Accept(this);
            }
          }
          
          if (first) {
            first = false;
            if (mc.OptAttributes != null) {
              foreach (var attr in mc.OptAttributes.Sections) {
                var section = ConvertAttributeSection(attr);
                if (section !=  null)
                  unit.AddChild(section, SyntaxTree.MemberRole);
              }
            }
          }
          
          if (nspace.Containers != null) {
            foreach (var subContainer in nspace.Containers) {
              subContainer.Accept(this);
            }
          }
          if (nDecl != null) {
            AddAttributeSection(nDecl, nspace.UnattachedAttributes, EntityDeclaration.UnattachedAttributeRole);
            if (loc != null && loc.Count > 2)
              nDecl.AddChild(new CSharpTokenNode(Convert(loc [2]), Roles.RBrace), Roles.RBrace);
            if (loc != null && loc.Count > 3)
              nDecl.AddChild(new CSharpTokenNode(Convert(loc [3]), Roles.Semicolon), Roles.Semicolon);
            
            namespaceStack.Pop();
          } else {
            AddAttributeSection(unit, nspace.UnattachedAttributes, EntityDeclaration.UnattachedAttributeRole);
          }
        }
        AddAttributeSection(unit, mc.UnattachedAttributes, EntityDeclaration.UnattachedAttributeRole);
      }

      #region Global

      readonly Stack<NamespaceDeclaration> namespaceStack = new Stack<NamespaceDeclaration>();

      void AddTypeArguments(ATypeNameExpression texpr, AstType result)
      {
        var unbound = texpr.TypeArguments as UnboundTypeArguments;
        if (unbound != null) { 
          var loc2 = LocationsBag.GetLocations(texpr.TypeArguments);
          if (loc2 == null)
            return;
          int j = 0;
          if (j < loc2.Count)
            result.AddChild(new CSharpTokenNode(Convert(loc2 [j++]), Roles.LChevron), Roles.LChevron);
          while (j < loc2.Count - 1) {
            result.AddChild (new SimpleType (), Roles.TypeArgument);
            result.AddChild(new CSharpTokenNode(Convert(loc2 [j++]), Roles.LChevron), Roles.Comma);
          }
          if (j < loc2.Count) {
            result.AddChild (new SimpleType (), Roles.TypeArgument);
            result.AddChild(new CSharpTokenNode(Convert(loc2 [j++]), Roles.RChevron), Roles.RChevron);
          }
          return;
        }
        if (texpr.TypeArguments == null || texpr.TypeArguments.Args == null)
          return;
        var loc = LocationsBag.GetLocations(texpr.TypeArguments);
        if (loc != null && loc.Count >= 2)
          result.AddChild(new CSharpTokenNode(Convert(loc [loc.Count - 2]), Roles.LChevron), Roles.LChevron);
        int i = 0;
        foreach (var arg in texpr.TypeArguments.Args) {
          result.AddChild(ConvertToType(arg), Roles.TypeArgument);
          if (loc != null && i < loc.Count - 2)
            result.AddChild(new CSharpTokenNode(Convert(loc [i++]), Roles.Comma), Roles.Comma);
        }
        if (loc != null && loc.Count >= 2)
          result.AddChild(new CSharpTokenNode(Convert(loc [loc.Count - 1]), Roles.RChevron), Roles.RChevron);
      }

      static AstType ConvertToType(TypeParameter spec)
      {
        AstType result;
        result = new SimpleType { IdentifierToken = Identifier.Create(spec.Name, Convert(spec.Location)) };
        return result;
      }

      AstType ConvertToType(MemberName memberName)
      {
        AstType result;
        if (memberName.Left != null) {
          result = new MemberType();
          result.AddChild(ConvertToType(memberName.Left), MemberType.TargetRole);
          var loc = LocationsBag.GetLocations(memberName);
          if (loc != null)
            result.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Dot), Roles.Dot);
          result.AddChild(Identifier.Create(memberName.Name, Convert(memberName.Location)), Roles.Identifier);
        } else {
          result = new SimpleType { IdentifierToken = Identifier.Create(memberName.Name, Convert(memberName.Location)) };
        }
        if (memberName.TypeParameters != null) {
          var chevronLocs = LocationsBag.GetLocations(memberName.TypeParameters);
          if (chevronLocs != null)
            result.AddChild(new CSharpTokenNode(Convert(chevronLocs [chevronLocs.Count - 2]), Roles.LChevron), Roles.LChevron);
          for (int i = 0; i < memberName.TypeParameters.Count; i++) {
            var param = memberName.TypeParameters [i];
            result.AddChild(new SimpleType(Identifier.Create(param.Name, Convert(param.Location))), Roles.TypeArgument);
            if (chevronLocs != null && i < chevronLocs.Count - 2)
              result.AddChild(new CSharpTokenNode(Convert(chevronLocs [i]), Roles.Comma), Roles.Comma);
          }
          if (chevronLocs != null)
            result.AddChild(new CSharpTokenNode(Convert(chevronLocs [chevronLocs.Count - 1]), Roles.RChevron), Roles.RChevron);
        }
        return result;
      }

      AstType ConvertToType(Mono.CSharp.Expression typeName)
      {
        if (typeName == null) // may happen in typeof(Generic<,,,,>)
          return new SimpleType();
        
        var typeExpr = typeName as TypeExpression;
        if (typeExpr != null) {
          return new PrimitiveType(typeExpr.GetSignatureForError(), Convert(typeExpr.Location));
        }
        
        var qam = typeName as QualifiedAliasMember;
        if (qam != null) {
          var loc = LocationsBag.GetLocations(typeName);
          var memberType = new MemberType();
          memberType.Target = new SimpleType(qam.alias, Convert(qam.Location));
          memberType.IsDoubleColon = true;

          if (loc != null && loc.Count > 0)
            memberType.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.DoubleColon), Roles.DoubleColon);

          memberType.MemberNameToken = Identifier.Create(qam.Name, loc != null ? Convert(loc [1]) : TextLocation.Empty);
          AddTypeArguments(qam, memberType);
          return memberType;
        }
        
        var ma = typeName as MemberAccess;
        if (ma != null) {
          var memberType = new MemberType();
          memberType.AddChild(ConvertToType(ma.LeftExpression), MemberType.TargetRole);
          var loc = LocationsBag.GetLocations(ma);
          if (loc != null)
            memberType.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Dot), Roles.Dot);

          memberType.MemberNameToken = Identifier.Create(ma.Name, Convert(ma.Location));
          
          AddTypeArguments(ma, memberType);
          return memberType;
        }
        
        var sn = typeName as SimpleName;
        if (sn != null) {
          var result = new SimpleType(sn.Name, Convert(sn.Location));
          AddTypeArguments(sn, result);
          return result;
        }
        
        var cc = typeName as ComposedCast;
        if (cc != null) {
          var baseType = ConvertToType(cc.Left);
          var result = new ComposedType { BaseType = baseType };
          var ccSpec = cc.Spec;
          while (ccSpec != null) {
            if (ccSpec.IsNullable) {
              result.AddChild(new CSharpTokenNode(Convert(ccSpec.Location), ComposedType.NullableRole), ComposedType.NullableRole);
            } else if (ccSpec.IsPointer) {
              result.AddChild(new CSharpTokenNode(Convert(ccSpec.Location), ComposedType.PointerRole), ComposedType.PointerRole);
            } else {
              var location = LocationsBag.GetLocations(ccSpec);
              var spec = new ArraySpecifier { Dimensions = ccSpec.Dimension };
              spec.AddChild(new CSharpTokenNode(Convert(ccSpec.Location), Roles.LBracket), Roles.LBracket);
              if (location != null)
                spec.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.RBracket), Roles.RBracket);
              
              result.ArraySpecifiers.Add(spec);
            }
            ccSpec = ccSpec.Next;
          }
          return result;
        }
        
        var sce = typeName as SpecialContraintExpr;
        if (sce != null) {
          switch (sce.Constraint) {
            case SpecialConstraint.Class:
              return new PrimitiveType("class", Convert(sce.Location));
            case SpecialConstraint.Struct:
              return new PrimitiveType("struct", Convert(sce.Location));
            case SpecialConstraint.Constructor:
              return new PrimitiveType("new", Convert(sce.Location));
          }
        }
        return new SimpleType("unknown");
      }

      IEnumerable<Attribute> GetAttributes(IEnumerable<Mono.CSharp.Attribute> optAttributes)
      {
        if (optAttributes == null)
          yield break;
        foreach (var attr in optAttributes) {
          var result = new Attribute();
          result.Type = ConvertToType(attr.TypeNameExpression);
          var loc = LocationsBag.GetLocations(attr);
          result.HasArgumentList = loc != null;
          int pos = 0;
          if (loc != null)
            result.AddChild(new CSharpTokenNode(Convert(loc [pos++]), Roles.LPar), Roles.LPar);
          
          if (attr.PositionalArguments != null) {
            foreach (var arg in attr.PositionalArguments) {
              if (arg == null)
                continue;
              var na = arg as NamedArgument;
              if (na != null) {
                var newArg = new NamedArgumentExpression();
                newArg.AddChild(Identifier.Create(na.Name, Convert(na.Location)), Roles.Identifier);
                
                var argLoc = LocationsBag.GetLocations(na);
                if (argLoc != null)
                  newArg.AddChild(new CSharpTokenNode(Convert(argLoc [0]), Roles.Colon), Roles.Colon);
                if (na.Expr != null)
                  newArg.AddChild((Expression)na.Expr.Accept(this), Roles.Expression);
                result.AddChild(newArg, Roles.Argument);
              } else {
                if (arg.Expr != null)
                  result.AddChild((Expression)arg.Expr.Accept(this), Roles.Argument);
              }
              if (loc != null && pos + 1 < loc.Count)
                result.AddChild(new CSharpTokenNode(Convert(loc [pos++]), Roles.Comma), Roles.Comma);
            }
          }
          if (attr.NamedArguments != null) {
            foreach (var arg in attr.NamedArguments) {
              var na = (NamedArgument)arg;
              var newArg = new NamedExpression();
              newArg.AddChild(Identifier.Create(na.Name, Convert(na.Location)), Roles.Identifier);
              
              var argLoc = LocationsBag.GetLocations(na);
              if (argLoc != null)
                newArg.AddChild(new CSharpTokenNode(Convert(argLoc [0]), Roles.Assign), Roles.Assign);
              if (na.Expr != null)
                newArg.AddChild((Expression)na.Expr.Accept(this), Roles.Expression);
              result.AddChild(newArg, Roles.Argument);
              if (loc != null && pos + 1 < loc.Count)
                result.AddChild(new CSharpTokenNode(Convert(loc [pos++]), Roles.Comma), Roles.Comma);
            }
          }
          if (loc != null && pos < loc.Count)
            result.AddChild(new CSharpTokenNode(Convert(loc [pos++]), Roles.RPar), Roles.RPar);
          
          yield return result;
        }
      }

      AttributeSection ConvertAttributeSection(IEnumerable<Mono.CSharp.Attribute> optAttributes)
      {
        if (optAttributes == null)
          return null;
        var result = new AttributeSection();
        var loc = LocationsBag.GetLocations(optAttributes);
        int pos = 0;
        if (loc != null)
          result.AddChild(new CSharpTokenNode(Convert(loc [pos++]), Roles.LBracket), Roles.LBracket);
        var first = optAttributes.FirstOrDefault();
        string target = first != null ? first.ExplicitTarget : null;
        
        if (!string.IsNullOrEmpty(target)) {
          if (loc != null && pos < loc.Count - 1) {
            result.AddChild(Identifier.Create(target, Convert(loc [pos++])), Roles.Identifier);
          } else {
            result.AddChild(Identifier.Create(target), Roles.Identifier);
          }
          if (loc != null && pos < loc.Count)
            result.AddChild(new CSharpTokenNode(Convert(loc [pos++]), Roles.Colon), Roles.Colon);
        }

        int attributeCount = 0;
        foreach (var attr in GetAttributes (optAttributes)) {
          result.AddChild(attr, Roles.Attribute);
          if (loc != null && pos + 1 < loc.Count)
            result.AddChild(new CSharpTokenNode(Convert(loc [pos++]), Roles.Comma), Roles.Comma);

          attributeCount++;
        }
        if (attributeCount == 0)
          return null;
        // Left and right bracket + commas between the attributes
        int locCount = 2 + attributeCount - 1;
        // optional comma
        if (loc != null && pos < loc.Count - 1 && loc.Count == locCount + 1)
          result.AddChild(new CSharpTokenNode(Convert(loc [pos++]), Roles.Comma), Roles.Comma);
        if (loc != null && pos < loc.Count)
          result.AddChild(new CSharpTokenNode(Convert(loc [pos++]), Roles.RBracket), Roles.RBracket);
        return result;
      }

      public override void Visit(NamespaceContainer ns)
      {
        NamespaceDeclaration nDecl = null;
        var loc = LocationsBag.GetLocations(ns);
        // <invalid> is caused by the parser - see Bug 12383 - [AST] Non existing namespaces generated
        if (ns.NS != null && !string.IsNullOrEmpty(ns.NS.Name) && !ns.NS.Name.EndsWith("<invalid>", StringComparison.Ordinal)) {
          nDecl = new NamespaceDeclaration();
          if (loc != null) {
            nDecl.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.NamespaceKeyword), Roles.NamespaceKeyword);
          }
          nDecl.AddChild(ConvertNamespaceName(ns.RealMemberName), NamespaceDeclaration.NamespaceNameRole);
          if (loc != null && loc.Count > 1) {
            nDecl.AddChild(new CSharpTokenNode(Convert(loc [1]), Roles.LBrace), Roles.LBrace);
          }

          AddToNamespace(nDecl);
          namespaceStack.Push(nDecl);
        }
        
        if (ns.Usings != null) {
          foreach (var us in ns.Usings) {
            us.Accept(this);
          }
        }
        
        if (ns.Containers != null) {
          foreach (var container in ns.Containers) {
            container.Accept(this);
          }
        }
        
        if (nDecl != null) {
          AddAttributeSection(nDecl, ns.UnattachedAttributes, EntityDeclaration.UnattachedAttributeRole);
          if (loc != null && loc.Count > 2)
            nDecl.AddChild(new CSharpTokenNode(Convert(loc [2]), Roles.RBrace), Roles.RBrace);
          if (loc != null && loc.Count > 3)
            nDecl.AddChild(new CSharpTokenNode(Convert(loc [3]), Roles.Semicolon), Roles.Semicolon);
          
          namespaceStack.Pop();
        }
      }
      //      public override void Visit (UsingsBag.Namespace nspace)
      //      {
      //
      //
      //        VisitNamespaceUsings (nspace);
      //        VisitNamespaceBody (nspace);
      //
      //      }
      //
      AstType ConvertNamespaceName(MemberName memberName)
      {
        // HACK for a parser 'bug' - sometimes it generates "<invalid>" identifiers in namespace names (on certain bugs in the input file)
        if (memberName.Name == "<invalid>")
          return AstType.Null;
        return ConvertToType(memberName);
      }

      public override void Visit(UsingNamespace un)
      {
        var ud = new UsingDeclaration();
        var loc = LocationsBag.GetLocations(un);
        ud.AddChild(new CSharpTokenNode(Convert(un.Location), UsingDeclaration.UsingKeywordRole), UsingDeclaration.UsingKeywordRole);
        if (un.NamespaceExpression != null)
          ud.AddChild(ConvertToType(un.NamespaceExpression), UsingDeclaration.ImportRole);
        if (loc != null)
          ud.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Semicolon), Roles.Semicolon);
        AddToNamespace(ud);
      }

      public override void Visit(UsingAliasNamespace uan)
      {
        var ud = new UsingAliasDeclaration();
        var loc = LocationsBag.GetLocations(uan);
        
        ud.AddChild(new CSharpTokenNode(Convert(uan.Location), UsingAliasDeclaration.UsingKeywordRole), UsingAliasDeclaration.UsingKeywordRole);
        ud.AddChild(Identifier.Create(uan.Alias.Value, Convert(uan.Alias.Location)), UsingAliasDeclaration.AliasRole);
        if (loc != null)
          ud.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Assign), Roles.Assign);
        if (uan.NamespaceExpression != null)
          ud.AddChild(ConvertToType(uan.NamespaceExpression), UsingAliasDeclaration.ImportRole);
        if (loc != null && loc.Count > 1)
          ud.AddChild(new CSharpTokenNode(Convert(loc [1]), Roles.Semicolon), Roles.Semicolon);
        AddToNamespace(ud);
      }

      public override void Visit(UsingExternAlias uea)
      {
        var ud = new ExternAliasDeclaration();
        var loc = LocationsBag.GetLocations(uea);
        ud.AddChild(new CSharpTokenNode(Convert(uea.Location), Roles.ExternKeyword), Roles.ExternKeyword);
        if (loc != null)
          ud.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.AliasKeyword), Roles.AliasKeyword);
        ud.AddChild(Identifier.Create(uea.Alias.Value, Convert(uea.Alias.Location)), Roles.Identifier);
        if (loc != null && loc.Count > 1)
          ud.AddChild(new CSharpTokenNode(Convert(loc [1]), Roles.Semicolon), Roles.Semicolon);
        AddToNamespace(ud);
      }

      AstType ConvertImport(MemberName memberName)
      {
        if (memberName.Left != null) {
          // left.name
          var t = new MemberType();
//          t.IsDoubleColon = memberName.IsDoubleColon;
          t.AddChild(ConvertImport(memberName.Left), MemberType.TargetRole);
          var loc = LocationsBag.GetLocations(memberName);
          if (loc != null)
            t.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Dot), Roles.Dot);
          
          t.AddChild(Identifier.Create(memberName.Name, Convert(memberName.Location)), Roles.Identifier);
          AddTypeArguments(t, memberName);
          return t;
        } else {
          var t = new SimpleType();
          t.AddChild(Identifier.Create(memberName.Name, Convert(memberName.Location)), Roles.Identifier);
          AddTypeArguments(t, memberName);
          return t;
        }
      }

      public override void Visit(MemberCore member)
      {
        Console.WriteLine("Unknown member:");
        Console.WriteLine(member.GetType() + "-> Member {0}", member.GetSignatureForError());
      }

      readonly Stack<TypeDeclaration> typeStack = new Stack<TypeDeclaration>();

      public override void Visit(Class c)
      {
        var newType = new TypeDeclaration();
        newType.ClassType = ClassType.Class;
        AddAttributeSection(newType, c);
        var location = LocationsBag.GetMemberLocation(c);
        AddModifiers(newType, location);
        int curLoc = 0;
        if (location != null && location.Count > 0)
          newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.ClassKeyword), Roles.ClassKeyword);
        
        newType.AddChild(Identifier.Create(c.MemberName.Name, Convert(c.MemberName.Location)), Roles.Identifier);
        AddTypeParameters(newType, c.MemberName);
        
        if (c.TypeBaseExpressions != null) {
          if (location != null && curLoc < location.Count)
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.Colon), Roles.Colon);
          
          var commaLocations = LocationsBag.GetLocations(c.TypeBaseExpressions);
          int i = 0;
          foreach (var baseTypes in c.TypeBaseExpressions) {
            newType.AddChild(ConvertToType(baseTypes), Roles.BaseType);
            if (commaLocations != null && i < commaLocations.Count) {
              newType.AddChild(new CSharpTokenNode(Convert(commaLocations [i]), Roles.Comma), Roles.Comma);
              i++;
            }
          }
        }
        
        AddConstraints(newType, c.CurrentTypeParameters);
        if (location != null && curLoc < location.Count)
          newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.LBrace), Roles.LBrace);
        typeStack.Push(newType);
        base.Visit(c);
        AddAttributeSection(newType, c.UnattachedAttributes, EntityDeclaration.UnattachedAttributeRole);

        if (location != null && curLoc < location.Count) {
          newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.RBrace), Roles.RBrace);
          
          if (location != null && curLoc < location.Count)
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.Semicolon), Roles.Semicolon);
          
        } else {
          // parser error, set end node to max value.
          newType.AddChild(new ErrorNode(), Roles.Error);
        }
        typeStack.Pop();
        AddType(newType);
      }

      public override void Visit(Struct s)
      {
        var newType = new TypeDeclaration();
        newType.ClassType = ClassType.Struct;
        AddAttributeSection(newType, s);
        var location = LocationsBag.GetMemberLocation(s);
        AddModifiers(newType, location);
        int curLoc = 0;
        if (location != null && location.Count > 0)
          newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.StructKeyword), Roles.StructKeyword);
        newType.AddChild(Identifier.Create(s.MemberName.Name, Convert(s.MemberName.Location)), Roles.Identifier);
        AddTypeParameters(newType, s.MemberName);
        
        if (s.TypeBaseExpressions != null) {
          if (location != null && curLoc < location.Count)
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.Colon), Roles.Colon);
          var commaLocations = LocationsBag.GetLocations(s.TypeBaseExpressions);
          int i = 0;
          foreach (var baseTypes in s.TypeBaseExpressions) {
            newType.AddChild(ConvertToType(baseTypes), Roles.BaseType);
            if (commaLocations != null && i < commaLocations.Count) {
              newType.AddChild(new CSharpTokenNode(Convert(commaLocations [i]), Roles.Comma), Roles.Comma);
              i++;
            }
          }
        }
        
        AddConstraints(newType, s.CurrentTypeParameters);
        if (location != null && curLoc < location.Count)
          newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.LBrace), Roles.LBrace);
        typeStack.Push(newType);
        base.Visit(s);
        if (location != null && location.Count > 2) {
          if (location != null && curLoc < location.Count)
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.RBrace), Roles.RBrace);
          if (location != null && curLoc < location.Count)
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.Semicolon), Roles.Semicolon);
        } else {
          // parser error, set end node to max value.
          newType.AddChild(new ErrorNode(), Roles.Error);
        }
        typeStack.Pop();
        AddType(newType);
      }

      public override void Visit(Interface i)
      {
        var newType = new TypeDeclaration();
        newType.ClassType = ClassType.Interface;
        AddAttributeSection(newType, i);
        var location = LocationsBag.GetMemberLocation(i);
        AddModifiers(newType, location);
        int curLoc = 0;
        if (location != null && location.Count > 0)
          newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.InterfaceKeyword), Roles.InterfaceKeyword);
        newType.AddChild(Identifier.Create(i.MemberName.Name, Convert(i.MemberName.Location)), Roles.Identifier);
        AddTypeParameters(newType, i.MemberName);
        
        if (i.TypeBaseExpressions != null) {
          if (location != null && curLoc < location.Count)
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.Colon), Roles.Colon);
          var commaLocations = LocationsBag.GetLocations(i.TypeBaseExpressions);
          int j = 0;
          foreach (var baseTypes in i.TypeBaseExpressions) {
            newType.AddChild(ConvertToType(baseTypes), Roles.BaseType);
            if (commaLocations != null && j < commaLocations.Count) {
              newType.AddChild(new CSharpTokenNode(Convert(commaLocations [j]), Roles.Comma), Roles.Comma);
              j++;
            }
          }
        }
        
        AddConstraints(newType, i.CurrentTypeParameters);
        if (location != null && curLoc < location.Count)
          newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.LBrace), Roles.LBrace);
        typeStack.Push(newType);
        base.Visit(i);
        if (location != null && location.Count > 2) {
          if (location != null && curLoc < location.Count)
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.RBrace), Roles.RBrace);
          if (location != null && curLoc < location.Count)
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.Semicolon), Roles.Semicolon);
        } else {
          // parser error, set end node to max value.
          newType.AddChild(new ErrorNode(), Roles.Error);
        }
        typeStack.Pop();
        AddType(newType);
      }

      public override void Visit(Mono.CSharp.Delegate d)
      {
        var newDelegate = new DelegateDeclaration();
        var location = LocationsBag.GetMemberLocation(d);
        AddAttributeSection(newDelegate, d);
        AddModifiers(newDelegate, location);
        if (location != null && location.Count > 0) {
          newDelegate.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.DelegateKeyword), Roles.DelegateKeyword);
        }
        if (d.ReturnType != null)
          newDelegate.AddChild(ConvertToType(d.ReturnType), Roles.Type);
        newDelegate.AddChild(Identifier.Create(d.MemberName.Name, Convert(d.MemberName.Location)), Roles.Identifier);
        AddTypeParameters(newDelegate, d.MemberName);
        
        if (location != null && location.Count > 1)
          newDelegate.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.LPar), Roles.LPar);
        AddParameter(newDelegate, d.Parameters);
        
        if (location != null && location.Count > 2) {
          newDelegate.AddChild(new CSharpTokenNode(Convert(location [2]), Roles.RPar), Roles.RPar);
        }
        AddConstraints(newDelegate, d.CurrentTypeParameters);
        if (location != null && location.Count > 3) {
          newDelegate.AddChild(new CSharpTokenNode(Convert(location [3]), Roles.Semicolon), Roles.Semicolon);
        }
        AddType(newDelegate);
      }

      void AddType(EntityDeclaration child)
      {
        if (typeStack.Count > 0) {
          typeStack.Peek().AddChild(child, Roles.TypeMemberRole);
        } else {
          AddToNamespace(child);
        }
      }

      void AddToNamespace(AstNode child)
      {
        if (namespaceStack.Count > 0) {
          namespaceStack.Peek().AddChild(child, NamespaceDeclaration.MemberRole);
        } else {
          unit.AddChild(child, SyntaxTree.MemberRole);
        }
      }

      public override void Visit(Mono.CSharp.Enum e)
      {
        var newType = new TypeDeclaration();
        newType.ClassType = ClassType.Enum;
        AddAttributeSection(newType, e);
        var location = LocationsBag.GetMemberLocation(e);
        
        AddModifiers(newType, location);
        int curLoc = 0;
        if (location != null && location.Count > 0)
          newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.EnumKeyword), Roles.EnumKeyword);
        newType.AddChild(Identifier.Create(e.MemberName.Name, Convert(e.MemberName.Location)), Roles.Identifier);
        
        if (e.BaseTypeExpression != null) {
          if (location != null && curLoc < location.Count)
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.Colon), Roles.Colon);
          newType.AddChild(ConvertToType(e.BaseTypeExpression), Roles.BaseType);
        }

        if (location != null && curLoc < location.Count)
          newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.LBrace), Roles.LBrace);
        typeStack.Push(newType);
        
        foreach (var m in e.Members) {
          var member = m as EnumMember;
          if (member == null) {
            Console.WriteLine("WARNING - ENUM MEMBER: " + m);
            continue;
          }
          Visit(member);
          if (location != null && curLoc < location.Count - 1) //last one is closing brace
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.Comma), Roles.Comma);
        }
        
        if (location != null && location.Count > 2) {
          if (location != null && curLoc < location.Count)
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.RBrace), Roles.RBrace);
          if (location != null && curLoc < location.Count)
            newType.AddChild(new CSharpTokenNode(Convert(location [curLoc++]), Roles.Semicolon), Roles.Semicolon);
        } else {
          // parser error, set end node to max value.
          newType.AddChild(new ErrorNode(), Roles.Error);
        }

        AddAttributeSection(newType, e.UnattachedAttributes, EntityDeclaration.UnattachedAttributeRole);
        typeStack.Pop();
        AddType(newType);
      }

      public override void Visit(EnumMember em)
      {
        var newField = new EnumMemberDeclaration();
        AddAttributeSection(newField, em);
        newField.AddChild(Identifier.Create(em.Name, Convert(em.Location)), Roles.Identifier);
        if (em.Initializer != null) {
          newField.AddChild(new CSharpTokenNode(Convert(em.Initializer.Location), Roles.Assign), Roles.Assign);
          newField.AddChild((Expression)em.Initializer.Accept(this), EnumMemberDeclaration.InitializerRole);
        }
        //Console.WriteLine (newField.StartLocation +"-" + newField.EndLocation);
        
        typeStack.Peek().AddChild(newField, Roles.TypeMemberRole);
      }

      #endregion

      #region Type members

      public override void Visit(FixedField f)
      {
        var location = LocationsBag.GetMemberLocation(f);
        int locationIdx = 0;
        
        var newField = new FixedFieldDeclaration();
        AddAttributeSection(newField, f);
        AddModifiers(newField, location);
        if (location != null && location.Count > 0)
          newField.AddChild(new CSharpTokenNode(Convert(location [locationIdx++]), FixedFieldDeclaration.FixedKeywordRole), FixedFieldDeclaration.FixedKeywordRole);

        if (f.TypeExpression != null)
          newField.AddChild(ConvertToType(f.TypeExpression), Roles.Type);
        
        var variable = new FixedVariableInitializer();
        variable.AddChild(Identifier.Create(f.MemberName.Name, Convert(f.MemberName.Location)), Roles.Identifier);
        if (f.Initializer != null && !f.Initializer.IsNull) {
          variable.AddChild(new CSharpTokenNode(Convert(f.Initializer.Location), Roles.LBracket), Roles.LBracket);
          
          variable.AddChild((Expression)f.Initializer.Accept(this), Roles.Expression);
          var bracketLocations = LocationsBag.GetLocations(f.Initializer);
          if (bracketLocations != null)
            variable.AddChild(new CSharpTokenNode(Convert(bracketLocations [0]), Roles.RBracket), Roles.RBracket);
        }
        newField.AddChild(variable, FixedFieldDeclaration.VariableRole);
        
        if (f.Declarators != null) {
          foreach (var decl in f.Declarators) {
            var declLoc = LocationsBag.GetLocations(decl);
            if (declLoc != null)
              newField.AddChild(new CSharpTokenNode(Convert(declLoc [0]), Roles.Comma), Roles.Comma);
            
            variable = new FixedVariableInitializer();
            variable.AddChild(Identifier.Create(decl.Name.Value, Convert(decl.Name.Location)), Roles.Identifier);
            variable.AddChild(new CSharpTokenNode(Convert(decl.Initializer.Location), Roles.LBracket), Roles.LBracket);
            variable.AddChild((Expression)decl.Initializer.Accept(this), Roles.Expression);
            var bracketLocations = LocationsBag.GetLocations(decl.Initializer);
            if (bracketLocations != null)
              variable.AddChild(new CSharpTokenNode(Convert(bracketLocations [0]), Roles.RBracket), Roles.RBracket);

            newField.AddChild(variable, FixedFieldDeclaration.VariableRole);
          }
        }
        if (location != null && location.Count > locationIdx)
          newField.AddChild(new CSharpTokenNode(Convert(location [locationIdx]), Roles.Semicolon), Roles.Semicolon);
        typeStack.Peek().AddChild(newField, Roles.TypeMemberRole);
        
      }

      public override void Visit(Field f)
      {
        var location = LocationsBag.GetMemberLocation(f);
        
        var newField = new FieldDeclaration();
        AddAttributeSection(newField, f);
        AddModifiers(newField, location);
        newField.AddChild(ConvertToType(f.TypeExpression), Roles.Type);
        
        var variable = new VariableInitializer();
        variable.AddChild(Identifier.Create(f.MemberName.Name, Convert(f.MemberName.Location)), Roles.Identifier);
        int locationIdx = 0;
        if (f.Initializer != null) {
          if (location != null)
            variable.AddChild(new CSharpTokenNode(Convert(location [locationIdx++]), Roles.Assign), Roles.Assign);
          variable.AddChild((Expression)f.Initializer.Accept(this), Roles.Expression);
        }
        newField.AddChild(variable, Roles.Variable);
        if (f.Declarators != null) {
          foreach (var decl in f.Declarators) {
            var declLoc = LocationsBag.GetLocations(decl);
            if (declLoc != null)
              newField.AddChild(new CSharpTokenNode(Convert(declLoc [0]), Roles.Comma), Roles.Comma);
            
            variable = new VariableInitializer();
            variable.AddChild(Identifier.Create(decl.Name.Value, Convert(decl.Name.Location)), Roles.Identifier);
            if (decl.Initializer != null) {
              if (declLoc != null)
                variable.AddChild(new CSharpTokenNode(Convert(declLoc [1]), Roles.Assign), Roles.Assign);
              variable.AddChild((Expression)decl.Initializer.Accept(this), Roles.Expression);
            }
            newField.AddChild(variable, Roles.Variable);
          }
        }
        if (location != null && location.Count > locationIdx)
          newField.AddChild(new CSharpTokenNode(Convert(location [locationIdx++]), Roles.Semicolon), Roles.Semicolon);

        typeStack.Peek().AddChild(newField, Roles.TypeMemberRole);
      }

      public override void Visit(Const c)
      {
        var location = LocationsBag.GetMemberLocation(c);
        
        var newField = new FieldDeclaration();
        AddAttributeSection(newField, c);
        AddModifiers(newField, location);
        if (location != null)
          newField.AddChild(new CSharpModifierToken(Convert(location [0]), Modifiers.Const), EntityDeclaration.ModifierRole);
        newField.AddChild(ConvertToType(c.TypeExpression), Roles.Type);
        
        var variable = new VariableInitializer();
        variable.AddChild(Identifier.Create(c.MemberName.Name, Convert(c.MemberName.Location)), Roles.Identifier);
        
        if (c.Initializer != null) {
          variable.AddChild(new CSharpTokenNode(Convert(c.Initializer.Location), Roles.Assign), Roles.Assign);
          variable.AddChild((Expression)c.Initializer.Accept(this), Roles.Expression);
        }
        newField.AddChild(variable, Roles.Variable);
        if (c.Declarators != null) {
          foreach (var decl in c.Declarators) {
            var declLoc = LocationsBag.GetLocations(decl);
            if (declLoc != null)
              newField.AddChild(new CSharpTokenNode(Convert(declLoc [0]), Roles.Comma), Roles.Comma);
            
            variable = new VariableInitializer();
            variable.AddChild(Identifier.Create(decl.Name.Value, Convert(decl.Name.Location)), Roles.Identifier);
            if (decl.Initializer != null) {
              variable.AddChild(new CSharpTokenNode(Convert(decl.Initializer.Location), Roles.Assign), Roles.Assign);
              variable.AddChild((Expression)decl.Initializer.Accept(this), Roles.Expression);
            }
            newField.AddChild(variable, Roles.Variable);
          }
        }
        if (location != null)
          newField.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.Semicolon), Roles.Semicolon);
        
        typeStack.Peek().AddChild(newField, Roles.TypeMemberRole);

        
      }

      public override void Visit(Operator o)
      {
        var newOperator = new OperatorDeclaration();
        newOperator.OperatorType = (OperatorType)o.OperatorType;
        
        var location = LocationsBag.GetMemberLocation(o);
        AddAttributeSection(newOperator, o);
        AddModifiers(newOperator, location);
        
        
        if (o.OperatorType == Operator.OpType.Implicit) {
          if (location != null && location.Count > 0) {
            newOperator.AddChild(new CSharpTokenNode(Convert(location [0]), OperatorDeclaration.ImplicitRole), OperatorDeclaration.ImplicitRole);
            if (location.Count > 1)
              newOperator.AddChild(new CSharpTokenNode(Convert(location [1]), OperatorDeclaration.OperatorKeywordRole), OperatorDeclaration.OperatorKeywordRole);
          }
          newOperator.AddChild(ConvertToType(o.TypeExpression), Roles.Type);
        } else if (o.OperatorType == Operator.OpType.Explicit) {
          if (location != null && location.Count > 0) {
            newOperator.AddChild(new CSharpTokenNode(Convert(location [0]), OperatorDeclaration.ExplicitRole), OperatorDeclaration.ExplicitRole);
            if (location.Count > 1)
              newOperator.AddChild(new CSharpTokenNode(Convert(location [1]), OperatorDeclaration.OperatorKeywordRole), OperatorDeclaration.OperatorKeywordRole);
          }
          newOperator.AddChild(ConvertToType(o.TypeExpression), Roles.Type);
        } else {
          newOperator.AddChild(ConvertToType(o.TypeExpression), Roles.Type);

          if (location != null && location.Count > 0)
            newOperator.AddChild(new CSharpTokenNode(Convert(location [0]), OperatorDeclaration.OperatorKeywordRole), OperatorDeclaration.OperatorKeywordRole);
          
          if (location != null && location.Count > 1) {
            var r = OperatorDeclaration.GetRole(newOperator.OperatorType);
            newOperator.AddChild(new CSharpTokenNode(Convert(location [1]), r), r);
          }
        }
        if (location != null && location.Count > 2)
          newOperator.AddChild(new CSharpTokenNode(Convert(location [2]), Roles.LPar), Roles.LPar);
        AddParameter(newOperator, o.ParameterInfo);
        if (location != null && location.Count > 3)
          newOperator.AddChild(new CSharpTokenNode(Convert(location [3]), Roles.RPar), Roles.RPar);
        
        if (o.Block != null) {
          newOperator.AddChild((BlockStatement)o.Block.Accept(this), Roles.Body);
        } else {
          if (location != null && location.Count >= 5)
            newOperator.AddChild(new CSharpTokenNode(Convert(location [4]), Roles.Semicolon), Roles.Semicolon);
        }
        typeStack.Peek().AddChild(newOperator, Roles.TypeMemberRole);
      }

      public void AddAttributeSection(AstNode parent, Attributable a)
      {
        if (a == null || a.OptAttributes == null)
          return;
        AddAttributeSection(parent, a.OptAttributes);
      }

      public void AddAttributeSection(AstNode parent, Attributes attrs, Role<AttributeSection> role)
      {
        if (attrs == null)
          return;
        foreach (var attr in attrs.Sections) {
          var section = ConvertAttributeSection(attr);
          if (section == null)
            continue;
          parent.AddChild(section, role);
        }
      }

      public void AddAttributeSection(AstNode parent, Attributes attrs)
      {
        AddAttributeSection(parent, attrs, EntityDeclaration.AttributeRole);
      }

      public override void Visit(Indexer i)
      {
        var newIndexer = new IndexerDeclaration();
        AddAttributeSection(newIndexer, i);
        var location = LocationsBag.GetMemberLocation(i);
        AddModifiers(newIndexer, location);
        newIndexer.AddChild(ConvertToType(i.TypeExpression), Roles.Type);
        AddExplicitInterface(newIndexer, i.MemberName);
        var name = i.MemberName;
        newIndexer.AddChild(new CSharpTokenNode(Convert(name.Location), IndexerDeclaration.ThisKeywordRole), IndexerDeclaration.ThisKeywordRole);
        
        if (location != null && location.Count > 0)
          newIndexer.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LBracket), Roles.LBracket);
        AddParameter(newIndexer, i.ParameterInfo);
        if (location != null && location.Count > 1)
          newIndexer.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RBracket), Roles.RBracket);
        
        if (location != null && location.Count > 2)
          newIndexer.AddChild(new CSharpTokenNode(Convert(location [2]), Roles.LBrace), Roles.LBrace);
        if (i.Get != null) {
          var getAccessor = new Accessor();
          var getLocation = LocationsBag.GetMemberLocation(i.Get);
          AddAttributeSection(getAccessor, i.Get);
          AddModifiers(getAccessor, getLocation);
          if (getLocation != null)
            getAccessor.AddChild(new CSharpTokenNode(Convert(i.Get.Location), PropertyDeclaration.GetKeywordRole), PropertyDeclaration.GetKeywordRole);
          if (i.Get.Block != null) {
            getAccessor.AddChild((BlockStatement)i.Get.Block.Accept(this), Roles.Body);
          } else {
            if (getLocation != null && getLocation.Count > 0)
              newIndexer.AddChild(new CSharpTokenNode(Convert(getLocation [0]), Roles.Semicolon), Roles.Semicolon);
          }
          newIndexer.AddChild(getAccessor, PropertyDeclaration.GetterRole);
        }
        
        if (i.Set != null) {
          var setAccessor = new Accessor();
          var setLocation = LocationsBag.GetMemberLocation(i.Set);
          AddAttributeSection(setAccessor, i.Set);
          AddModifiers(setAccessor, setLocation);
          if (setLocation != null)
            setAccessor.AddChild(new CSharpTokenNode(Convert(i.Set.Location), PropertyDeclaration.SetKeywordRole), PropertyDeclaration.SetKeywordRole);
          
          if (i.Set.Block != null) {
            setAccessor.AddChild((BlockStatement)i.Set.Block.Accept(this), Roles.Body);
          } else {
            if (setLocation != null && setLocation.Count > 0)
              newIndexer.AddChild(new CSharpTokenNode(Convert(setLocation [0]), Roles.Semicolon), Roles.Semicolon);
          }
          newIndexer.AddChild(setAccessor, PropertyDeclaration.SetterRole);
        }
        
        if (location != null) {
          if (location.Count > 3)
            newIndexer.AddChild(new CSharpTokenNode(Convert(location [3]), Roles.RBrace), Roles.RBrace);
        } else {
          // parser error, set end node to max value.
          newIndexer.AddChild(new ErrorNode(), Roles.Error);
        }
        typeStack.Peek().AddChild(newIndexer, Roles.TypeMemberRole);
      }

      public override void Visit(Method m)
      {
        var newMethod = new MethodDeclaration();
        AddAttributeSection(newMethod, m);
        var location = LocationsBag.GetMemberLocation(m);
        AddModifiers(newMethod, location);
        newMethod.AddChild(ConvertToType(m.TypeExpression), Roles.Type);
        AddExplicitInterface(newMethod, m.MethodName);
        newMethod.AddChild(Identifier.Create(m.MethodName.Name, Convert(m.Location)), Roles.Identifier);
        
        AddTypeParameters(newMethod, m.MemberName);
        
        if (location != null && location.Count > 0)
          newMethod.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        AddParameter(newMethod, m.ParameterInfo);
        
        if (location != null && location.Count > 1)
          newMethod.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        
        AddConstraints(newMethod, m.CurrentTypeParameters);
        
        if (m.Block != null) {
          var bodyBlock = (BlockStatement)m.Block.Accept(this);
//          if (m.Block is ToplevelBlock) {
//            newMethod.AddChild (bodyBlock.FirstChild.NextSibling, Roles.Body);
//          } else {
          newMethod.AddChild(bodyBlock, Roles.Body);
//          }
        } else if (location != null) {
          if (location.Count < 3) {
            // parser error, set end node to max value.
            newMethod.AddChild(new ErrorNode(), Roles.Error);
          } else {
            newMethod.AddChild(new CSharpTokenNode(Convert(location [2]), Roles.Semicolon), Roles.Semicolon);
          }
        }
        typeStack.Peek().AddChild(newMethod, Roles.TypeMemberRole);
      }

      static readonly Dictionary<Mono.CSharp.Modifiers, Modifiers> modifierTable = new Dictionary<Mono.CSharp.Modifiers, Modifiers>();
      static readonly string[] keywordTable;

      static ConversionVisitor()
      {
        modifierTable [Mono.CSharp.Modifiers.NEW] = Modifiers.New;
        modifierTable [Mono.CSharp.Modifiers.PUBLIC] = Modifiers.Public;
        modifierTable [Mono.CSharp.Modifiers.PROTECTED] = Modifiers.Protected;
        modifierTable [Mono.CSharp.Modifiers.PRIVATE] = Modifiers.Private;
        modifierTable [Mono.CSharp.Modifiers.INTERNAL] = Modifiers.Internal;
        modifierTable [Mono.CSharp.Modifiers.ABSTRACT] = Modifiers.Abstract;
        modifierTable [Mono.CSharp.Modifiers.VIRTUAL] = Modifiers.Virtual;
        modifierTable [Mono.CSharp.Modifiers.SEALED] = Modifiers.Sealed;
        modifierTable [Mono.CSharp.Modifiers.STATIC] = Modifiers.Static;
        modifierTable [Mono.CSharp.Modifiers.OVERRIDE] = Modifiers.Override;
        modifierTable [Mono.CSharp.Modifiers.READONLY] = Modifiers.Readonly;
        modifierTable [Mono.CSharp.Modifiers.PARTIAL] = Modifiers.Partial;
        modifierTable [Mono.CSharp.Modifiers.EXTERN] = Modifiers.Extern;
        modifierTable [Mono.CSharp.Modifiers.VOLATILE] = Modifiers.Volatile;
        modifierTable [Mono.CSharp.Modifiers.UNSAFE] = Modifiers.Unsafe;
        modifierTable [Mono.CSharp.Modifiers.ASYNC] = Modifiers.Async;
        
        keywordTable = new string[255];
        for (int i = 0; i< keywordTable.Length; i++)
          keywordTable [i] = "unknown";
        
        keywordTable [(int)BuiltinTypeSpec.Type.Other] = "void";
        keywordTable [(int)BuiltinTypeSpec.Type.String] = "string";
        keywordTable [(int)BuiltinTypeSpec.Type.Int] = "int";
        keywordTable [(int)BuiltinTypeSpec.Type.Object] = "object";
        keywordTable [(int)BuiltinTypeSpec.Type.Float] = "float";
        keywordTable [(int)BuiltinTypeSpec.Type.Double] = "double";
        keywordTable [(int)BuiltinTypeSpec.Type.Long] = "long";
        keywordTable [(int)BuiltinTypeSpec.Type.Byte] = "byte";
        keywordTable [(int)BuiltinTypeSpec.Type.UInt] = "uint";
        keywordTable [(int)BuiltinTypeSpec.Type.ULong] = "ulong";
        keywordTable [(int)BuiltinTypeSpec.Type.Short] = "short";
        keywordTable [(int)BuiltinTypeSpec.Type.UShort] = "ushort";
        keywordTable [(int)BuiltinTypeSpec.Type.SByte] = "sbyte";
        keywordTable [(int)BuiltinTypeSpec.Type.Decimal] = "decimal";
        keywordTable [(int)BuiltinTypeSpec.Type.Char] = "char";
        keywordTable [(int)BuiltinTypeSpec.Type.Bool] = "bool";
      }

      static void AddModifiers(EntityDeclaration parent, LocationsBag.MemberLocations location)
      {
        if (location == null || location.Modifiers == null)
          return;
        foreach (var modifier in location.Modifiers) {
          Modifiers mod;
          if (!modifierTable.TryGetValue(modifier.Item1, out mod)) {
            Console.WriteLine("modifier " + modifier.Item1 + " can't be converted,");
          }
          
          parent.AddChild(new CSharpModifierToken(Convert(modifier.Item2), mod), EntityDeclaration.ModifierRole);
        }
      }

      public override void Visit(Property p)
      {
        var newProperty = new PropertyDeclaration();
        AddAttributeSection(newProperty, p);
        var location = LocationsBag.GetMemberLocation(p);
        AddModifiers(newProperty, location);
        newProperty.AddChild(ConvertToType(p.TypeExpression), Roles.Type);
        AddExplicitInterface(newProperty, p.MemberName);
        newProperty.AddChild(Identifier.Create(p.MemberName.Name, Convert(p.Location)), Roles.Identifier);
        
        if (location != null && location.Count > 0)
          newProperty.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LBrace), Roles.LBrace);
        
        Accessor getAccessor = null;
        if (p.Get != null) {
          getAccessor = new Accessor();
          AddAttributeSection(getAccessor, p.Get);
          var getLocation = LocationsBag.GetMemberLocation(p.Get);
          AddModifiers(getAccessor, getLocation);
          getAccessor.AddChild(new CSharpTokenNode(Convert(p.Get.Location), PropertyDeclaration.GetKeywordRole), PropertyDeclaration.GetKeywordRole);
          
          if (p.Get.Block != null) {
            getAccessor.AddChild((BlockStatement)p.Get.Block.Accept(this), Roles.Body);
          } else {
            if (getLocation != null && getLocation.Count > 0)
              getAccessor.AddChild(new CSharpTokenNode(Convert(getLocation [0]), Roles.Semicolon), Roles.Semicolon);
          }
        }
        
        Accessor setAccessor = null;
        if (p.Set != null) {
          setAccessor = new Accessor();
          AddAttributeSection(setAccessor, p.Set);
          var setLocation = LocationsBag.GetMemberLocation(p.Set);
          AddModifiers(setAccessor, setLocation);
          setAccessor.AddChild(new CSharpTokenNode(Convert(p.Set.Location), PropertyDeclaration.SetKeywordRole), PropertyDeclaration.SetKeywordRole);
          
          if (p.Set.Block != null) {
            setAccessor.AddChild((BlockStatement)p.Set.Block.Accept(this), Roles.Body);
          } else {
            if (setLocation != null && setLocation.Count > 0)
              setAccessor.AddChild(new CSharpTokenNode(Convert(setLocation [0]), Roles.Semicolon), Roles.Semicolon);
          }
        }
        if (getAccessor != null && setAccessor != null) {
          if (getAccessor.StartLocation < setAccessor.StartLocation) {
            newProperty.AddChild(getAccessor, PropertyDeclaration.GetterRole);
            newProperty.AddChild(setAccessor, PropertyDeclaration.SetterRole);
          } else {
            newProperty.AddChild(setAccessor, PropertyDeclaration.SetterRole);
            newProperty.AddChild(getAccessor, PropertyDeclaration.GetterRole);
          }
        } else {
          if (getAccessor != null)
            newProperty.AddChild(getAccessor, PropertyDeclaration.GetterRole);
          if (setAccessor != null)
            newProperty.AddChild(setAccessor, PropertyDeclaration.SetterRole);
        }
        
        if (location != null && location.Count > 1) {
          newProperty.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RBrace), Roles.RBrace);
        } else {
          // parser error, set end node to max value.
          newProperty.AddChild(new ErrorNode(), Roles.Error);
        }
        
        typeStack.Peek().AddChild(newProperty, Roles.TypeMemberRole);
      }

      public override void Visit(Constructor c)
      {
        var newConstructor = new ConstructorDeclaration();
        AddAttributeSection(newConstructor, c);
        var location = LocationsBag.GetMemberLocation(c);
        AddModifiers(newConstructor, location);
        newConstructor.AddChild(Identifier.Create(c.MemberName.Name, Convert(c.MemberName.Location)), Roles.Identifier);
        if (location != null && location.Count > 0)
          newConstructor.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        
        AddParameter(newConstructor, c.ParameterInfo);
        if (location != null && location.Count > 1)
          newConstructor.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        
        if (c.Initializer != null) {
          var initializer = new ConstructorInitializer();
          initializer.ConstructorInitializerType = c.Initializer is ConstructorBaseInitializer ? ConstructorInitializerType.Base : ConstructorInitializerType.This;
          var initializerLocation = LocationsBag.GetLocations(c.Initializer);
          
          if (initializerLocation != null)
            newConstructor.AddChild(new CSharpTokenNode(Convert(initializerLocation [0]), Roles.Colon), Roles.Colon);
          
          if (initializerLocation != null && initializerLocation.Count > 1) {
            // this and base has the same length
            var r = initializer.ConstructorInitializerType == ConstructorInitializerType.This ? ConstructorInitializer.ThisKeywordRole : ConstructorInitializer.BaseKeywordRole;
            initializer.AddChild(new CSharpTokenNode(Convert(c.Initializer.Location), r), r);
            initializer.AddChild(new CSharpTokenNode(Convert(initializerLocation [1]), Roles.LPar), Roles.LPar);
            AddArguments(initializer, c.Initializer.Arguments);
            initializer.AddChild(new CSharpTokenNode(Convert(initializerLocation [2]), Roles.RPar), Roles.RPar);
            newConstructor.AddChild(initializer, ConstructorDeclaration.InitializerRole);
          }
        }
        
        if (c.Block != null)
          newConstructor.AddChild((BlockStatement)c.Block.Accept(this), Roles.Body);
        typeStack.Peek().AddChild(newConstructor, Roles.TypeMemberRole);
      }

      public override void Visit(Destructor d)
      {
        var newDestructor = new DestructorDeclaration();
        AddAttributeSection(newDestructor, d);
        var location = LocationsBag.GetMemberLocation(d);
        AddModifiers(newDestructor, location);
        if (location != null && location.Count > 0)
          newDestructor.AddChild(new CSharpTokenNode(Convert(location [0]), DestructorDeclaration.TildeRole), DestructorDeclaration.TildeRole);
        newDestructor.AddChild(Identifier.Create(d.Identifier, Convert(d.MemberName.Location)), Roles.Identifier);
        
        if (location != null && location.Count > 1) {
          newDestructor.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.LPar), Roles.LPar);
          
          if (location.Count > 2)
            newDestructor.AddChild(new CSharpTokenNode(Convert(location [2]), Roles.RPar), Roles.RPar);
        }
        
        if (d.Block != null)
          newDestructor.AddChild((BlockStatement)d.Block.Accept(this), Roles.Body);
        
        typeStack.Peek().AddChild(newDestructor, Roles.TypeMemberRole);
      }

      public override void Visit(EventField e)
      {
        var newEvent = new EventDeclaration();
        AddAttributeSection(newEvent, e);
        var location = LocationsBag.GetMemberLocation(e);
        int l = 0;
        AddModifiers(newEvent, location);
        
        if (location != null && location.Count > 0)
          newEvent.AddChild(new CSharpTokenNode(Convert(location [l++]), EventDeclaration.EventKeywordRole), EventDeclaration.EventKeywordRole);
        newEvent.AddChild(ConvertToType(e.TypeExpression), Roles.Type);
        
        var variable = new VariableInitializer();
        variable.AddChild(Identifier.Create(e.MemberName.Name, Convert(e.MemberName.Location)), Roles.Identifier);
        
        if (e.Initializer != null) {
          if (location != null && location.Count > l)
            variable.AddChild(new CSharpTokenNode(Convert(location [l++]), Roles.Assign), Roles.Assign);
          variable.AddChild((Expression)e.Initializer.Accept(this), Roles.Expression);
        }
        newEvent.AddChild(variable, Roles.Variable);
        if (e.Declarators != null) {
          foreach (var decl in e.Declarators) {
            var declLoc = LocationsBag.GetLocations(decl);
            if (declLoc != null)
              newEvent.AddChild(new CSharpTokenNode(Convert(declLoc [0]), Roles.Comma), Roles.Comma);
            
            variable = new VariableInitializer();
            variable.AddChild(Identifier.Create(decl.Name.Value, Convert(decl.Name.Location)), Roles.Identifier);

            if (decl.Initializer != null) {
              if (declLoc != null)
                variable.AddChild(new CSharpTokenNode(Convert(declLoc [1]), Roles.Assign), Roles.Assign);
              variable.AddChild((Expression)decl.Initializer.Accept(this), Roles.Expression);
            }
            newEvent.AddChild(variable, Roles.Variable);
          }
        }
        
        if (location != null && location.Count > l)
          newEvent.AddChild(new CSharpTokenNode(Convert(location [l++]), Roles.Semicolon), Roles.Semicolon);
        
        typeStack.Peek().AddChild(newEvent, Roles.TypeMemberRole);
      }

      void AddExplicitInterface(AstNode parent, MemberName memberName)
      {
        if (memberName == null || memberName.ExplicitInterface == null)
          return;
        
        parent.AddChild(ConvertToType(memberName.ExplicitInterface), EntityDeclaration.PrivateImplementationTypeRole);
        var privateImplTypeLoc = LocationsBag.GetLocations(memberName.ExplicitInterface);
        if (privateImplTypeLoc != null)
          parent.AddChild(new CSharpTokenNode(Convert(privateImplTypeLoc [0]), Roles.Dot), Roles.Dot);
      }

      public override void Visit(EventProperty ep)
      {
        var newEvent = new CustomEventDeclaration();
        AddAttributeSection(newEvent, ep);
        var location = LocationsBag.GetMemberLocation(ep);
        AddModifiers(newEvent, location);
        
        if (location != null && location.Count > 0)
          newEvent.AddChild(new CSharpTokenNode(Convert(location [0]), CustomEventDeclaration.EventKeywordRole), CustomEventDeclaration.EventKeywordRole);
        newEvent.AddChild(ConvertToType(ep.TypeExpression), Roles.Type);
        
        AddExplicitInterface(newEvent, ep.MemberName);
        
        newEvent.AddChild(Identifier.Create(ep.MemberName.Name, Convert(ep.Location)), Roles.Identifier);

        if (location != null && location.Count >= 2)
          newEvent.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.LBrace), Roles.LBrace);
        
        if (ep.Add != null) {
          var addAccessor = new Accessor();
          AddAttributeSection(addAccessor, ep.Add);
          var addLocation = LocationsBag.GetMemberLocation(ep.Add);
          AddModifiers(addAccessor, addLocation);
          addAccessor.AddChild(new CSharpTokenNode(Convert(ep.Add.Location), CustomEventDeclaration.AddKeywordRole), CustomEventDeclaration.AddKeywordRole);
          if (ep.Add.Block != null)
            addAccessor.AddChild((BlockStatement)ep.Add.Block.Accept(this), Roles.Body);
          newEvent.AddChild(addAccessor, CustomEventDeclaration.AddAccessorRole);
        }
        
        if (ep.Remove != null) {
          var removeAccessor = new Accessor();
          AddAttributeSection(removeAccessor, ep.Remove);
          var removeLocation = LocationsBag.GetMemberLocation(ep.Remove);
          AddModifiers(removeAccessor, removeLocation);
          removeAccessor.AddChild(new CSharpTokenNode(Convert(ep.Remove.Location), CustomEventDeclaration.RemoveKeywordRole), CustomEventDeclaration.RemoveKeywordRole);
          
          if (ep.Remove.Block != null)
            removeAccessor.AddChild((BlockStatement)ep.Remove.Block.Accept(this), Roles.Body);
          newEvent.AddChild(removeAccessor, CustomEventDeclaration.RemoveAccessorRole);
        }
        if (location != null && location.Count >= 3) {
          newEvent.AddChild(new CSharpTokenNode(Convert(location [2]), Roles.RBrace), Roles.RBrace);
        } else {
          // parser error, set end node to max value.
          newEvent.AddChild(new ErrorNode(), Roles.Error);
        }
        
        typeStack.Peek().AddChild(newEvent, Roles.TypeMemberRole);
      }

      #endregion

      #region Statements

      public override object Visit(Mono.CSharp.Statement stmt)
      {
        Console.WriteLine("unknown statement:" + stmt);
        return null;
      }

      public override object Visit(BlockVariable blockVariableDeclaration)
      {
        var result = new VariableDeclarationStatement();
        result.AddChild(ConvertToType(blockVariableDeclaration.TypeExpression), Roles.Type);
        
        var varInit = new VariableInitializer();
        var location = LocationsBag.GetLocations(blockVariableDeclaration);
        varInit.AddChild(Identifier.Create(blockVariableDeclaration.Variable.Name, Convert(blockVariableDeclaration.Variable.Location)), Roles.Identifier);
        if (blockVariableDeclaration.Initializer != null) {
          if (location != null && location.Count > 0)
            varInit.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Assign), Roles.Assign);
          varInit.AddChild((Expression)blockVariableDeclaration.Initializer.Accept(this), Roles.Expression);
        }
        
        result.AddChild(varInit, Roles.Variable);
        
        if (blockVariableDeclaration.Declarators != null) {
          foreach (var decl in blockVariableDeclaration.Declarators) {
            var loc = LocationsBag.GetLocations(decl);
            var init = new VariableInitializer();
            if (loc != null && loc.Count > 0)
              result.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Comma), Roles.Comma);
            init.AddChild(Identifier.Create(decl.Variable.Name, Convert(decl.Variable.Location)), Roles.Identifier);
            if (decl.Initializer != null) {
              if (loc != null && loc.Count > 1)
                init.AddChild(new CSharpTokenNode(Convert(loc [1]), Roles.Assign), Roles.Assign);
              init.AddChild((Expression)decl.Initializer.Accept(this), Roles.Expression);
            }
            result.AddChild(init, Roles.Variable);
          }
        }
        if (location != null && (blockVariableDeclaration.Initializer == null || location.Count > 1))
          result.AddChild(new CSharpTokenNode(Convert(location [location.Count - 1]), Roles.Semicolon), Roles.Semicolon);
        return result;
      }

      public override object Visit(BlockConstant blockConstantDeclaration)
      {
        var result = new VariableDeclarationStatement();
        
        var location = LocationsBag.GetLocations(blockConstantDeclaration);
        if (location != null && location.Count > 0)
          result.AddChild(new CSharpModifierToken(Convert(location [0]), Modifiers.Const), VariableDeclarationStatement.ModifierRole);
        
        result.AddChild(ConvertToType(blockConstantDeclaration.TypeExpression), Roles.Type);
        
        var varInit = new VariableInitializer();
        varInit.AddChild(Identifier.Create(blockConstantDeclaration.Variable.Name, Convert(blockConstantDeclaration.Variable.Location)), Roles.Identifier);
        if (blockConstantDeclaration.Initializer != null) {
          if (location != null && location.Count > 1)
            varInit.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.Assign), Roles.Assign);
          varInit.AddChild((Expression)blockConstantDeclaration.Initializer.Accept(this), Roles.Expression);
        }
        
        result.AddChild(varInit, Roles.Variable);
        
        if (blockConstantDeclaration.Declarators != null) {
          foreach (var decl in blockConstantDeclaration.Declarators) {
            var loc = LocationsBag.GetLocations(decl);
            var init = new VariableInitializer();
            init.AddChild(Identifier.Create(decl.Variable.Name, Convert(decl.Variable.Location)), Roles.Identifier);
            if (decl.Initializer != null) {
              if (loc != null)
                init.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Assign), Roles.Assign);
              init.AddChild((Expression)decl.Initializer.Accept(this), Roles.Expression);
              if (loc != null && loc.Count > 1)
                result.AddChild(new CSharpTokenNode(Convert(loc [1]), Roles.Comma), Roles.Comma);
            } else {
              if (loc != null && loc.Count > 0)
                result.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Comma), Roles.Comma);
            }
            result.AddChild(init, Roles.Variable);
          }
        }
        if (location != null) {
          result.AddChild(new CSharpTokenNode(Convert(location [location.Count - 1]), Roles.Semicolon), Roles.Semicolon);
        } else {
          // parser error, set end node to max value.
          result.AddChild(new ErrorNode(), Roles.Error);
        }
        return result;
      }

      public override object Visit(Mono.CSharp.EmptyStatement emptyStatement)
      {
        var result = new EmptyStatement();
        result.Location = Convert(emptyStatement.loc);
        return result;
      }

      public override object Visit(Mono.CSharp.ErrorExpression errorExpression)
      {
        return new ErrorExpression(Convert(errorExpression.Location));
      }

      public override object Visit(EmptyExpressionStatement emptyExpressionStatement)
      {
        // Should never happen.
        throw new NotSupportedException();
      }

      public override object Visit(If ifStatement)
      {
        var result = new IfElseStatement();
        
        var location = LocationsBag.GetLocations(ifStatement);
        
        result.AddChild(new CSharpTokenNode(Convert(ifStatement.loc), IfElseStatement.IfKeywordRole), IfElseStatement.IfKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        if (ifStatement.Expr != null)
          result.AddChild((Expression)ifStatement.Expr.Accept(this), Roles.Condition);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        
        if (ifStatement.TrueStatement != null)
          result.AddChild((Statement)ifStatement.TrueStatement.Accept(this), IfElseStatement.TrueRole);
        
        if (ifStatement.FalseStatement != null) {
          if (location != null && location.Count > 2)
            result.AddChild(new CSharpTokenNode(Convert(location [2]), IfElseStatement.ElseKeywordRole), IfElseStatement.ElseKeywordRole);
          result.AddChild((Statement)ifStatement.FalseStatement.Accept(this), IfElseStatement.FalseRole);
        }
        
        return result;
      }

      public override object Visit(Do doStatement)
      {
        var result = new DoWhileStatement();
        var location = LocationsBag.GetLocations(doStatement);
        result.AddChild(new CSharpTokenNode(Convert(doStatement.loc), DoWhileStatement.DoKeywordRole), DoWhileStatement.DoKeywordRole);
        if (doStatement.Statement != null)
          result.AddChild((Statement)doStatement.Statement.Accept(this), Roles.EmbeddedStatement);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), DoWhileStatement.WhileKeywordRole), DoWhileStatement.WhileKeywordRole);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.LPar), Roles.LPar);
        if (doStatement.expr != null)
          result.AddChild((Expression)doStatement.expr.Accept(this), Roles.Condition);
        if (location != null && location.Count > 2) {
          result.AddChild(new CSharpTokenNode(Convert(location [2]), Roles.RPar), Roles.RPar);
          if (location.Count > 3)
            result.AddChild(new CSharpTokenNode(Convert(location [3]), Roles.Semicolon), Roles.Semicolon);
        }
        
        return result;
      }

      public override object Visit(While whileStatement)
      {
        var result = new WhileStatement();
        var location = LocationsBag.GetLocations(whileStatement);
        result.AddChild(new CSharpTokenNode(Convert(whileStatement.loc), WhileStatement.WhileKeywordRole), WhileStatement.WhileKeywordRole);
        
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        if (whileStatement.expr != null)
          result.AddChild((Expression)whileStatement.expr.Accept(this), Roles.Condition);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        if (whileStatement.Statement != null)
          result.AddChild((Statement)whileStatement.Statement.Accept(this), Roles.EmbeddedStatement);
        return result;
      }

      void AddStatementOrList(ForStatement forStatement, Mono.CSharp.Statement init, Role<Statement> role)
      {
        if (init == null)
          return;
        var stmtList = init as StatementList;
        if (stmtList != null) {
          foreach (var stmt in stmtList.Statements) {
            forStatement.AddChild((Statement)stmt.Accept(this), role);
          }
        } else if (init is Mono.CSharp.EmptyStatement) {
          
        } else {
          forStatement.AddChild((Statement)init.Accept(this), role);
        }
      }

      public override object Visit(For forStatement)
      {
        var result = new ForStatement();
        
        var location = LocationsBag.GetLocations(forStatement);
        
        result.AddChild(new CSharpTokenNode(Convert(forStatement.loc), ForStatement.ForKeywordRole), ForStatement.ForKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        
        AddStatementOrList(result, forStatement.Initializer, ForStatement.InitializerRole);
        
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.Semicolon), Roles.Semicolon);
        if (forStatement.Condition != null)
          result.AddChild((Expression)forStatement.Condition.Accept(this), Roles.Condition);
        if (location != null && location.Count >= 3)
          result.AddChild(new CSharpTokenNode(Convert(location [2]), Roles.Semicolon), Roles.Semicolon);
        
        AddStatementOrList(result, forStatement.Iterator, ForStatement.IteratorRole);
        
        if (location != null && location.Count >= 4)
          result.AddChild(new CSharpTokenNode(Convert(location [3]), Roles.RPar), Roles.RPar);
        
        if (forStatement.Statement != null)
          result.AddChild((Statement)forStatement.Statement.Accept(this), Roles.EmbeddedStatement);
        
        return result;
      }

      public override object Visit(StatementExpression statementExpression)
      {
        var result = new ExpressionStatement();
        var expr = statementExpression.Expr.Accept(this) as Expression;
        if (expr != null)
          result.AddChild(expr, Roles.Expression);
        var location = LocationsBag.GetLocations(statementExpression);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Semicolon), Roles.Semicolon);
        return result;
      }

      public override object Visit(StatementErrorExpression errorStatement)
      {
        var result = new ExpressionStatement();
        var expr = errorStatement.Expr.Accept(this) as Expression;
        if (expr != null)
          result.AddChild(expr, Roles.Expression);
        var location = LocationsBag.GetLocations(errorStatement);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Semicolon), Roles.Semicolon);
        return result;
      }

      public override object Visit(InvalidStatementExpression invalidStatementExpression)
      {
        var result = new ExpressionStatement();
        if (invalidStatementExpression.Expression == null)
          return result;
        var expr = invalidStatementExpression.Expression.Accept(this) as Expression;
        if (expr != null)
          result.AddChild(expr, Roles.Expression);
        var location = LocationsBag.GetLocations(invalidStatementExpression);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Semicolon), Roles.Semicolon);
        return result;
      }

      public override object Visit(Return returnStatement)
      {
        var result = new ReturnStatement();
        
        result.AddChild(new CSharpTokenNode(Convert(returnStatement.loc), ReturnStatement.ReturnKeywordRole), ReturnStatement.ReturnKeywordRole);
        if (returnStatement.Expr != null)
          result.AddChild((Expression)returnStatement.Expr.Accept(this), Roles.Expression);
        
        var location = LocationsBag.GetLocations(returnStatement);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Semicolon), Roles.Semicolon);
        
        return result;
      }

      public override object Visit(Goto gotoStatement)
      {
        var result = new GotoStatement();
        var location = LocationsBag.GetLocations(gotoStatement);
        result.AddChild(new CSharpTokenNode(Convert(gotoStatement.loc), GotoStatement.GotoKeywordRole), GotoStatement.GotoKeywordRole);
        var loc = location != null ? Convert(location [0]) : TextLocation.Empty;
        result.AddChild(Identifier.Create(gotoStatement.Target, loc), Roles.Identifier);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.Semicolon), Roles.Semicolon);
        
        return result;
      }

      public override object Visit(LabeledStatement labeledStatement)
      {
        var result = new LabelStatement();
        result.AddChild(Identifier.Create(labeledStatement.Name, Convert(labeledStatement.loc)), Roles.Identifier);
        var location = LocationsBag.GetLocations(labeledStatement);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Colon), Roles.Colon);
        return result;
      }

      public override object Visit(GotoDefault gotoDefault)
      {
        var result = new GotoDefaultStatement();
        result.AddChild(new CSharpTokenNode(Convert(gotoDefault.loc), GotoDefaultStatement.GotoKeywordRole), GotoDefaultStatement.GotoKeywordRole);
        var location = LocationsBag.GetLocations(gotoDefault);
        if (location != null) {
          result.AddChild(new CSharpTokenNode(Convert(location [0]), GotoDefaultStatement.DefaultKeywordRole), GotoDefaultStatement.DefaultKeywordRole);
          if (location.Count > 1)
            result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.Semicolon), Roles.Semicolon);
        }
        
        return result;
      }

      public override object Visit(GotoCase gotoCase)
      {
        var result = new GotoCaseStatement();
        result.AddChild(new CSharpTokenNode(Convert(gotoCase.loc), GotoCaseStatement.GotoKeywordRole), GotoCaseStatement.GotoKeywordRole);
        
        var location = LocationsBag.GetLocations(gotoCase);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), GotoCaseStatement.CaseKeywordRole), GotoCaseStatement.CaseKeywordRole);
        if (gotoCase.Expr != null)
          result.AddChild((Expression)gotoCase.Expr.Accept(this), Roles.Expression);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.Semicolon), Roles.Semicolon);
        return result;
      }

      public override object Visit(Throw throwStatement)
      {
        var result = new ThrowStatement();
        var location = LocationsBag.GetLocations(throwStatement);
        
        result.AddChild(new CSharpTokenNode(Convert(throwStatement.loc), ThrowStatement.ThrowKeywordRole), ThrowStatement.ThrowKeywordRole);
        if (throwStatement.Expr != null)
          result.AddChild((Expression)throwStatement.Expr.Accept(this), Roles.Expression);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Semicolon), Roles.Semicolon);
        return result;
      }

      public override object Visit(Break breakStatement)
      {
        var result = new BreakStatement();
        var location = LocationsBag.GetLocations(breakStatement);
        
        result.AddChild(new CSharpTokenNode(Convert(breakStatement.loc), BreakStatement.BreakKeywordRole), BreakStatement.BreakKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Semicolon), Roles.Semicolon);
        return result;
      }

      public override object Visit(Continue continueStatement)
      {
        var result = new ContinueStatement();
        var location = LocationsBag.GetLocations(continueStatement);
        result.AddChild(new CSharpTokenNode(Convert(continueStatement.loc), ContinueStatement.ContinueKeywordRole), ContinueStatement.ContinueKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Semicolon), Roles.Semicolon);
        return result;
      }

      public static bool IsLower(Location left, Location right)
      {
        return left.Row < right.Row || left.Row == right.Row && left.Column < right.Column;
      }

      public UsingStatement CreateUsingStatement(Block blockStatement)
      {
        var usingResult = new UsingStatement();
        Mono.CSharp.Statement cur = blockStatement.Statements [0];
        var u = cur as Using;
        if (u != null) {
          usingResult.AddChild(new CSharpTokenNode(Convert(u.loc), UsingStatement.UsingKeywordRole), UsingStatement.UsingKeywordRole);
          usingResult.AddChild(new CSharpTokenNode(Convert(blockStatement.StartLocation), Roles.LPar), Roles.LPar);
          if (u.Variables != null) {
            var initializer = new VariableInitializer {
              NameToken = Identifier.Create(u.Variables.Variable.Name, Convert(u.Variables.Variable.Location)),
            };
            
            var loc = LocationsBag.GetLocations(u.Variables);
            if (loc != null)
              initializer.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Assign), Roles.Assign);
            if (u.Variables.Initializer != null)
              initializer.Initializer = u.Variables.Initializer.Accept(this) as Expression;
            
            
            var varDec = new VariableDeclarationStatement {
              Type = ConvertToType(u.Variables.TypeExpression),
              Variables = { initializer }
            };
            
            if (u.Variables.Declarators != null) {
              foreach (var decl in u.Variables.Declarators) {
                var declLoc = LocationsBag.GetLocations(decl);
                var init = new VariableInitializer();
                if (declLoc != null && declLoc.Count > 0)
                  varDec.AddChild(new CSharpTokenNode(Convert(declLoc [0]), Roles.Comma), Roles.Comma);
                init.AddChild(Identifier.Create(decl.Variable.Name, Convert(decl.Variable.Location)), Roles.Identifier);
                if (decl.Initializer != null) {
                  if (declLoc != null && declLoc.Count > 1)
                    init.AddChild(new CSharpTokenNode(Convert(declLoc [1]), Roles.Assign), Roles.Assign);
                  init.AddChild((Expression)decl.Initializer.Accept(this), Roles.Expression);
                }
                varDec.AddChild(init, Roles.Variable);
              }
            }
            usingResult.AddChild(varDec, UsingStatement.ResourceAcquisitionRole);
          }
          cur = u.Statement;
          usingResult.AddChild(new CSharpTokenNode(Convert(blockStatement.EndLocation), Roles.RPar), Roles.RPar);
          if (cur != null)
            usingResult.AddChild((Statement)cur.Accept(this), Roles.EmbeddedStatement);
        }
        return usingResult;
      }

      void AddBlockChildren(BlockStatement result, Block blockStatement, ref int curLocal)
      {
        if (convertTypeSystemMode) {
          return;
        }
        foreach (Mono.CSharp.Statement stmt in blockStatement.Statements) {
          if (stmt == null)
            continue;
          /*          if (curLocal < localVariables.Count && IsLower (localVariables[curLocal].Location, stmt.loc)) {
            result.AddChild (CreateVariableDeclaration (localVariables[curLocal]), Roles.Statement);
            curLocal++;
          }*/
          if (stmt is Block && !(stmt is ToplevelBlock || stmt is ExplicitBlock)) {
            AddBlockChildren(result, (Block)stmt, ref curLocal);
          } else {
            result.AddChild((Statement)stmt.Accept(this), BlockStatement.StatementRole);
          }
        }
      }

      public override object Visit(Block blockStatement)
      {
        if (blockStatement.IsCompilerGenerated && blockStatement.Statements.Any()) {
          if (blockStatement.Statements.First() is Using)
            return CreateUsingStatement(blockStatement);
          return blockStatement.Statements.Last().Accept(this);
        }
        var result = new BlockStatement();
        result.AddChild(new CSharpTokenNode(Convert(blockStatement.StartLocation), Roles.LBrace), Roles.LBrace);
        int curLocal = 0;
        AddBlockChildren(result, blockStatement, ref curLocal);
        
        result.AddChild(new CSharpTokenNode(Convert(blockStatement.EndLocation), Roles.RBrace), Roles.RBrace);
        return result;
      }

      public override object Visit(Switch switchStatement)
      {
        var result = new SwitchStatement();
        
        var location = LocationsBag.GetLocations(switchStatement);
        result.AddChild(new CSharpTokenNode(Convert(switchStatement.loc), SwitchStatement.SwitchKeywordRole), SwitchStatement.SwitchKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        if (switchStatement.Expr != null)
          result.AddChild((Expression)switchStatement.Expr.Accept(this), Roles.Expression);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        if (location != null && location.Count > 2)
          result.AddChild(new CSharpTokenNode(Convert(location [2]), Roles.LBrace), Roles.LBrace);
        SwitchSection newSection = null;
        bool lastWasCase = false, added = true;
        if (switchStatement.Block != null) {
          foreach (var child in switchStatement.Block.Statements) {
            var statement = child.Accept(this);
            var caseLabel = statement as CaseLabel;
            if (caseLabel != null) {
              if (!lastWasCase) {
                newSection = new SwitchSection();
                added = false;
              }
              newSection.AddChild(caseLabel, SwitchSection.CaseLabelRole);
              lastWasCase = true;
            } else {
              if (lastWasCase) {
                result.AddChild(newSection, SwitchStatement.SwitchSectionRole);
                lastWasCase = false;
                added = true;
              }
              newSection.AddChild((Statement)statement, Roles.EmbeddedStatement);
            }
          }
        }
        if (!added)
          result.AddChild(newSection, SwitchStatement.SwitchSectionRole);

        if (location != null && location.Count > 3) {
          result.AddChild(new CSharpTokenNode(Convert(location [3]), Roles.RBrace), Roles.RBrace);
        } else {
          // parser error, set end node to max value.
          result.AddChild(new ErrorNode(), Roles.Error);
        }
        
        return result;
      }

      public override object Visit(SwitchLabel switchLabel)
      {
        var newLabel = new CaseLabel();
        if (!switchLabel.IsDefault) {
          newLabel.AddChild(new CSharpTokenNode(Convert(switchLabel.Location), CaseLabel.CaseKeywordRole), CaseLabel.CaseKeywordRole);
          if (switchLabel.Label != null)
            newLabel.AddChild((Expression)switchLabel.Label.Accept(this), Roles.Expression);
          var colonLocation = LocationsBag.GetLocations(switchLabel);
          if (colonLocation != null)
            newLabel.AddChild(new CSharpTokenNode(Convert(colonLocation [0]), Roles.Colon), Roles.Colon);
        } else {
          newLabel.AddChild(new CSharpTokenNode(Convert(switchLabel.Location), CaseLabel.DefaultKeywordRole), CaseLabel.DefaultKeywordRole);
          newLabel.AddChild(new CSharpTokenNode(new TextLocation(switchLabel.Location.Row, switchLabel.Location.Column + "default".Length), Roles.Colon), Roles.Colon);
        }
        return newLabel;
      }

      public override object Visit(Lock lockStatement)
      {
        var result = new LockStatement();
        var location = LocationsBag.GetLocations(lockStatement);
        result.AddChild(new CSharpTokenNode(Convert(lockStatement.loc), LockStatement.LockKeywordRole), LockStatement.LockKeywordRole);
        
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        if (lockStatement.Expr != null)
          result.AddChild((Expression)lockStatement.Expr.Accept(this), Roles.Expression);
        
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        if (lockStatement.Statement != null)
          result.AddChild((Statement)lockStatement.Statement.Accept(this), Roles.EmbeddedStatement);
        
        return result;
      }

      public override object Visit(Unchecked uncheckedStatement)
      {
        var result = new UncheckedStatement();
        result.AddChild(new CSharpTokenNode(Convert(uncheckedStatement.loc), UncheckedStatement.UncheckedKeywordRole), UncheckedStatement.UncheckedKeywordRole);
        if (uncheckedStatement.Block != null)
          result.AddChild((BlockStatement)uncheckedStatement.Block.Accept(this), Roles.Body);
        return result;
      }

      public override object Visit(Checked checkedStatement)
      {
        var result = new CheckedStatement();
        result.AddChild(new CSharpTokenNode(Convert(checkedStatement.loc), CheckedStatement.CheckedKeywordRole), CheckedStatement.CheckedKeywordRole);
        if (checkedStatement.Block != null)
          result.AddChild((BlockStatement)checkedStatement.Block.Accept(this), Roles.Body);
        return result;
      }

      public override object Visit(Unsafe unsafeStatement)
      {
        var result = new UnsafeStatement();
        result.AddChild(new CSharpTokenNode(Convert(unsafeStatement.loc), UnsafeStatement.UnsafeKeywordRole), UnsafeStatement.UnsafeKeywordRole);
        if (unsafeStatement.Block != null)
          result.AddChild((BlockStatement)unsafeStatement.Block.Accept(this), Roles.Body);
        return result;
      }

      public override object Visit(Fixed fixedStatement)
      {
        var result = new FixedStatement();
        var location = LocationsBag.GetLocations(fixedStatement);
        
        result.AddChild(new CSharpTokenNode(Convert(fixedStatement.loc), FixedStatement.FixedKeywordRole), FixedStatement.FixedKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        
        if (fixedStatement.Variables != null) {
          var blockVariableDeclaration = fixedStatement.Variables;
          result.AddChild(ConvertToType(blockVariableDeclaration.TypeExpression), Roles.Type);
          var varInit = new VariableInitializer();
          var initLocation = LocationsBag.GetLocations(blockVariableDeclaration);
          varInit.AddChild(Identifier.Create(blockVariableDeclaration.Variable.Name, Convert(blockVariableDeclaration.Variable.Location)), Roles.Identifier);
          if (blockVariableDeclaration.Initializer != null) {
            if (initLocation != null)
              varInit.AddChild(new CSharpTokenNode(Convert(initLocation [0]), Roles.Assign), Roles.Assign);
            varInit.AddChild((Expression)blockVariableDeclaration.Initializer.Accept(this), Roles.Expression);
          }
          
          result.AddChild(varInit, Roles.Variable);
          
          if (blockVariableDeclaration.Declarators != null) {
            foreach (var decl in blockVariableDeclaration.Declarators) {
              var loc = LocationsBag.GetLocations(decl);
              var init = new VariableInitializer();
              if (loc != null && loc.Count > 0)
                result.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Comma), Roles.Comma);
              init.AddChild(Identifier.Create(decl.Variable.Name, Convert(decl.Variable.Location)), Roles.Identifier);
              if (decl.Initializer != null) {
                if (loc != null && loc.Count > 1)
                  init.AddChild(new CSharpTokenNode(Convert(loc [1]), Roles.Assign), Roles.Assign);
                init.AddChild((Expression)decl.Initializer.Accept(this), Roles.Expression);
              }
              result.AddChild(init, Roles.Variable);
            }
          }
        }
        
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        if (fixedStatement.Statement != null)
          result.AddChild((Statement)fixedStatement.Statement.Accept(this), Roles.EmbeddedStatement);
        return result;
      }

      public override object Visit(TryFinally tryFinallyStatement)
      {
        TryCatchStatement result;
        var location = LocationsBag.GetLocations(tryFinallyStatement);
        
        if (tryFinallyStatement.Stmt is TryCatch) {
          result = (TryCatchStatement)tryFinallyStatement.Stmt.Accept(this);
        } else {
          result = new TryCatchStatement();
          result.AddChild(new CSharpTokenNode(Convert(tryFinallyStatement.loc), TryCatchStatement.TryKeywordRole), TryCatchStatement.TryKeywordRole);
          if (tryFinallyStatement.Stmt != null)
            result.AddChild((BlockStatement)tryFinallyStatement.Stmt.Accept(this), TryCatchStatement.TryBlockRole);
        }
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), TryCatchStatement.FinallyKeywordRole), TryCatchStatement.FinallyKeywordRole);
        if (tryFinallyStatement.Fini != null)
          result.AddChild((BlockStatement)tryFinallyStatement.Fini.Accept(this), TryCatchStatement.FinallyBlockRole);
        
        return result;
      }

      CatchClause ConvertCatch(Catch ctch)
      {
        var result = new CatchClause();
        var location = LocationsBag.GetLocations(ctch);
        result.AddChild(new CSharpTokenNode(Convert(ctch.loc), CatchClause.CatchKeywordRole), CatchClause.CatchKeywordRole);
        if (ctch.TypeExpression != null) {
          if (location != null)
            result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
          
          if (ctch.TypeExpression != null)
            result.AddChild(ConvertToType(ctch.TypeExpression), Roles.Type);
          if (ctch.Variable != null && !string.IsNullOrEmpty(ctch.Variable.Name))
            result.AddChild(Identifier.Create(ctch.Variable.Name, Convert(ctch.Variable.Location)), Roles.Identifier);
          
          if (location != null && location.Count > 1)
            result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        }

        if (ctch.Block != null)
          result.AddChild((BlockStatement)ctch.Block.Accept(this), Roles.Body);
        
        return result;
      }

      public override object Visit(TryCatch tryCatchStatement)
      {
        var result = new TryCatchStatement();
        result.AddChild(new CSharpTokenNode(Convert(tryCatchStatement.loc), TryCatchStatement.TryKeywordRole), TryCatchStatement.TryKeywordRole);
        if (tryCatchStatement.Block != null)
          result.AddChild((BlockStatement)tryCatchStatement.Block.Accept(this), TryCatchStatement.TryBlockRole);
        if (tryCatchStatement.Clauses != null) {
          foreach (var ctch in tryCatchStatement.Clauses) {
            result.AddChild(ConvertCatch(ctch), TryCatchStatement.CatchClauseRole);
          }
        }
//        if (tryCatchStatement.General != null)
//          result.AddChild (ConvertCatch (tryCatchStatement.General), TryCatchStatement.CatchClauseRole);
        
        return result;
      }

      public override object Visit(Using usingStatement)
      {
        var result = new UsingStatement();
        var location = LocationsBag.GetLocations(usingStatement);
        
        result.AddChild(new CSharpTokenNode(Convert(usingStatement.loc), UsingStatement.UsingKeywordRole), UsingStatement.UsingKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        if (usingStatement.Expr != null)
          result.AddChild((AstNode)usingStatement.Expr.Accept(this), UsingStatement.ResourceAcquisitionRole);
        
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        
        if (usingStatement.Statement != null)
          result.AddChild((Statement)usingStatement.Statement.Accept(this), Roles.EmbeddedStatement);
        return result;
      }

      public override object Visit(Foreach foreachStatement)
      {
        var result = new ForeachStatement();
        
        var location = LocationsBag.GetLocations(foreachStatement);
        
        result.AddChild(new CSharpTokenNode(Convert(foreachStatement.loc), ForeachStatement.ForeachKeywordRole), ForeachStatement.ForeachKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        
        if (foreachStatement.TypeExpression != null)
          result.AddChild(ConvertToType(foreachStatement.TypeExpression), Roles.Type);
        
        if (foreachStatement.Variable != null)
          result.AddChild(Identifier.Create(foreachStatement.Variable.Name, Convert(foreachStatement.Variable.Location)), Roles.Identifier);
        
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), ForeachStatement.InKeywordRole), ForeachStatement.InKeywordRole);
        
        if (foreachStatement.Expr != null)
          result.AddChild((Expression)foreachStatement.Expr.Accept(this), Roles.Expression);
        
        if (location != null && location.Count > 2)
          result.AddChild(new CSharpTokenNode(Convert(location [2]), Roles.RPar), Roles.RPar);
        
        if (foreachStatement.Statement != null)
          result.AddChild((Statement)foreachStatement.Statement.Accept(this), Roles.EmbeddedStatement);
        
        return result;
      }

      public override object Visit(Yield yieldStatement)
      {
        var result = new YieldReturnStatement();
        var location = LocationsBag.GetLocations(yieldStatement);
        
        result.AddChild(new CSharpTokenNode(Convert(yieldStatement.loc), YieldReturnStatement.YieldKeywordRole), YieldReturnStatement.YieldKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), YieldReturnStatement.ReturnKeywordRole), YieldReturnStatement.ReturnKeywordRole);
        if (yieldStatement.Expr != null)
          result.AddChild((Expression)yieldStatement.Expr.Accept(this), Roles.Expression);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.Semicolon), Roles.Semicolon);
        
        return result;
      }

      public override object Visit(YieldBreak yieldBreakStatement)
      {
        var result = new YieldBreakStatement();
        var location = LocationsBag.GetLocations(yieldBreakStatement);
        result.AddChild(new CSharpTokenNode(Convert(yieldBreakStatement.loc), YieldBreakStatement.YieldKeywordRole), YieldBreakStatement.YieldKeywordRole);
        if (location != null) {
          result.AddChild(new CSharpTokenNode(Convert(location [0]), YieldBreakStatement.BreakKeywordRole), YieldBreakStatement.BreakKeywordRole);
          if (location.Count > 1)
            result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.Semicolon), Roles.Semicolon);
        }
        return result;
      }

      #endregion

      #region Expression

      public override object Visit(Mono.CSharp.Expression expression)
      {
        Console.WriteLine("Visit unknown expression:" + expression);
        Console.WriteLine(Environment.StackTrace);
        return null;
      }

      public override object Visit(DefaultParameterValueExpression defaultParameterValueExpression)
      {
        return defaultParameterValueExpression.Child.Accept(this);
      }

      public override object Visit(TypeExpression typeExpression)
      {
        return new TypeReferenceExpression(new PrimitiveType(keywordTable [(int)typeExpression.Type.BuiltinType], Convert(typeExpression.Location)));
      }

      public override object Visit(LocalVariableReference localVariableReference)
      {
        return Identifier.Create(localVariableReference.Name, Convert(localVariableReference.Location));
      }

      public override object Visit(MemberAccess memberAccess)
      {
        Expression result;
        var ind = memberAccess.LeftExpression as Indirection;
        if (ind != null) {
          result = new PointerReferenceExpression();
          result.AddChild((Expression)ind.Expr.Accept(this), Roles.TargetExpression);
          result.AddChild(new CSharpTokenNode(Convert(ind.Location), PointerReferenceExpression.ArrowRole), PointerReferenceExpression.ArrowRole);
        } else {
          result = new MemberReferenceExpression();
          if (memberAccess.LeftExpression != null) {
            var leftExpr = memberAccess.LeftExpression.Accept(this);
            result.AddChild((Expression)leftExpr, Roles.TargetExpression);
          }
          var loc = LocationsBag.GetLocations(memberAccess);

          if (loc != null) {
            result.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Dot), Roles.Dot);
          }
        }
        
        result.AddChild(Identifier.Create(memberAccess.Name, Convert(memberAccess.Location)), Roles.Identifier);
        
        AddTypeArguments(result, memberAccess);
        return result;
      }

      public override object Visit(QualifiedAliasMember qualifiedAliasMember)
      {
        var result = new MemberType();
        result.Target = new SimpleType(qualifiedAliasMember.alias, Convert(qualifiedAliasMember.Location));
        result.IsDoubleColon = true;
        var location = LocationsBag.GetLocations(qualifiedAliasMember);
        if (location != null && location.Count > 0)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.DoubleColon), Roles.DoubleColon);

        AddTypeArguments(result, qualifiedAliasMember);
        result.AddChild(Identifier.Create(qualifiedAliasMember.Name, location != null && location.Count > 1 ? Convert(location [1]) : TextLocation.Empty), Roles.Identifier);
        return  new TypeReferenceExpression { Type = result };
      }

      public override object Visit(Constant constant)
      {
        if (constant.GetValue() == null)
          return new NullReferenceExpression(Convert(constant.Location));
        string literalValue;
        var literalConstant = constant as ILiteralConstant;
        literalValue = literalConstant != null ? new string(literalConstant.ParsedValue) : constant.GetValueAsLiteral();
        object val = constant.GetValue();
        if (val is bool)
          literalValue = (bool)val ? "true" : "false";
        var result = new PrimitiveExpression(val, Convert(constant.Location), literalValue);
        return result;
      }

      public override object Visit(SimpleName simpleName)
      {
        var result = new IdentifierExpression();
        result.AddChild(Identifier.Create(simpleName.Name, Convert(simpleName.Location)), Roles.Identifier);
        AddTypeArguments(result, simpleName);
        return result;
      }

      public override object Visit(BooleanExpression booleanExpression)
      {
        return booleanExpression.Expr.Accept(this);
      }

      public override object Visit(Mono.CSharp.ParenthesizedExpression parenthesizedExpression)
      {
        var result = new ParenthesizedExpression();
        var location = LocationsBag.GetLocations(parenthesizedExpression);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        if (parenthesizedExpression.Expr != null)
          result.AddChild((Expression)parenthesizedExpression.Expr.Accept(this), Roles.Expression);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        return result;
      }

      public override object Visit(Unary unaryExpression)
      {
        var result = new UnaryOperatorExpression();
        switch (unaryExpression.Oper) {
          case Unary.Operator.UnaryPlus:
            result.Operator = UnaryOperatorType.Plus;
            break;
          case Unary.Operator.UnaryNegation:
            result.Operator = UnaryOperatorType.Minus;
            break;
          case Unary.Operator.LogicalNot:
            result.Operator = UnaryOperatorType.Not;
            break;
          case Unary.Operator.OnesComplement:
            result.Operator = UnaryOperatorType.BitNot;
            break;
          case Unary.Operator.AddressOf:
            result.Operator = UnaryOperatorType.AddressOf;
            break;
        }
        var r = UnaryOperatorExpression.GetOperatorRole(result.Operator);
        result.AddChild(new CSharpTokenNode(Convert(unaryExpression.Location), r), r);
        if (unaryExpression.Expr != null)
          result.AddChild((Expression)unaryExpression.Expr.Accept(this), Roles.Expression);
        return result;
      }

      public override object Visit(UnaryMutator unaryMutatorExpression)
      {
        var result = new UnaryOperatorExpression();
        if (unaryMutatorExpression.Expr == null)
          return result;
        var expression = (Expression)unaryMutatorExpression.Expr.Accept(this);
        switch (unaryMutatorExpression.UnaryMutatorMode) {
          case UnaryMutator.Mode.PostDecrement:
            result.Operator = UnaryOperatorType.PostDecrement;
            result.AddChild(expression, Roles.Expression);
            result.AddChild(new CSharpTokenNode(Convert(unaryMutatorExpression.Location), UnaryOperatorExpression.DecrementRole), UnaryOperatorExpression.DecrementRole);
            break;
          case UnaryMutator.Mode.PostIncrement:
            result.Operator = UnaryOperatorType.PostIncrement;
            result.AddChild(expression, Roles.Expression);
            result.AddChild(new CSharpTokenNode(Convert(unaryMutatorExpression.Location), UnaryOperatorExpression.IncrementRole), UnaryOperatorExpression.IncrementRole);
            break;
            
          case UnaryMutator.Mode.PreIncrement:
            result.Operator = UnaryOperatorType.Increment;
            result.AddChild(new CSharpTokenNode(Convert(unaryMutatorExpression.Location), UnaryOperatorExpression.IncrementRole), UnaryOperatorExpression.IncrementRole);
            result.AddChild(expression, Roles.Expression);
            break;
          case UnaryMutator.Mode.PreDecrement:
            result.Operator = UnaryOperatorType.Decrement;
            result.AddChild(new CSharpTokenNode(Convert(unaryMutatorExpression.Location), UnaryOperatorExpression.DecrementRole), UnaryOperatorExpression.DecrementRole);
            result.AddChild(expression, Roles.Expression);
            break;
        }
        
        return result;
      }

      public override object Visit(Indirection indirectionExpression)
      {
        var result = new UnaryOperatorExpression();
        result.Operator = UnaryOperatorType.Dereference;
        result.AddChild(new CSharpTokenNode(Convert(indirectionExpression.Location), UnaryOperatorExpression.DereferenceRole), UnaryOperatorExpression.DereferenceRole);
        if (indirectionExpression.Expr != null)
          result.AddChild((Expression)indirectionExpression.Expr.Accept(this), Roles.Expression);
        return result;
      }

      public override object Visit(Is isExpression)
      {
        var result = new IsExpression();
        if (isExpression.Expr != null)
          result.AddChild((Expression)isExpression.Expr.Accept(this), Roles.Expression);
        result.AddChild(new CSharpTokenNode(Convert(isExpression.Location), IsExpression.IsKeywordRole), IsExpression.IsKeywordRole);
        
        if (isExpression.ProbeType != null)
          result.AddChild(ConvertToType(isExpression.ProbeType), Roles.Type);
        return result;
      }

      public override object Visit(As asExpression)
      {
        var result = new AsExpression();
        if (asExpression.Expr != null)
          result.AddChild((Expression)asExpression.Expr.Accept(this), Roles.Expression);
        result.AddChild(new CSharpTokenNode(Convert(asExpression.Location), AsExpression.AsKeywordRole), AsExpression.AsKeywordRole);
        if (asExpression.ProbeType != null)
          result.AddChild(ConvertToType(asExpression.ProbeType), Roles.Type);
        return result;
      }

      public override object Visit(Cast castExpression)
      {
        var result = new CastExpression();
        var location = LocationsBag.GetLocations(castExpression);
        
        result.AddChild(new CSharpTokenNode(Convert(castExpression.Location), Roles.LPar), Roles.LPar);
        if (castExpression.TargetType != null)
          result.AddChild(ConvertToType(castExpression.TargetType), Roles.Type);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.RPar), Roles.RPar);
        if (castExpression.Expr != null)
          result.AddChild((Expression)castExpression.Expr.Accept(this), Roles.Expression);
        return result;
      }

      public override object Visit(ComposedCast composedCast)
      {
        var result = new ComposedType();
        result.AddChild(ConvertToType(composedCast.Left), Roles.Type);
        
        var spec = composedCast.Spec;
        while (spec != null) {
          if (spec.IsNullable) {
            result.AddChild(new CSharpTokenNode(Convert(spec.Location), ComposedType.NullableRole), ComposedType.NullableRole);
          } else if (spec.IsPointer) {
            result.AddChild(new CSharpTokenNode(Convert(spec.Location), ComposedType.PointerRole), ComposedType.PointerRole);
          } else {
            var aSpec = new ArraySpecifier();
            aSpec.AddChild(new CSharpTokenNode(Convert(spec.Location), Roles.LBracket), Roles.LBracket);
            var location = LocationsBag.GetLocations(spec);
            if (location != null)
              aSpec.AddChild(new CSharpTokenNode(Convert(spec.Location), Roles.RBracket), Roles.RBracket);
            result.AddChild(aSpec, ComposedType.ArraySpecifierRole);
          }
          spec = spec.Next;
        }
        
        return result;
      }

      public override object Visit(Mono.CSharp.DefaultValueExpression defaultValueExpression)
      {
        var result = new DefaultValueExpression();
        result.AddChild(new CSharpTokenNode(Convert(defaultValueExpression.Location), DefaultValueExpression.DefaultKeywordRole), DefaultValueExpression.DefaultKeywordRole);
        var location = LocationsBag.GetLocations(defaultValueExpression);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        result.AddChild(ConvertToType(defaultValueExpression.Expr), Roles.Type);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        return result;
      }

      public override object Visit(Binary binaryExpression)
      {
        var result = new BinaryOperatorExpression();
        switch (binaryExpression.Oper) {
          case Binary.Operator.Multiply:
            result.Operator = BinaryOperatorType.Multiply;
            break;
          case Binary.Operator.Division:
            result.Operator = BinaryOperatorType.Divide;
            break;
          case Binary.Operator.Modulus:
            result.Operator = BinaryOperatorType.Modulus;
            break;
          case Binary.Operator.Addition:
            result.Operator = BinaryOperatorType.Add;
            break;
          case Binary.Operator.Subtraction:
            result.Operator = BinaryOperatorType.Subtract;
            break;
          case Binary.Operator.LeftShift:
            result.Operator = BinaryOperatorType.ShiftLeft;
            break;
          case Binary.Operator.RightShift:
            result.Operator = BinaryOperatorType.ShiftRight;
            break;
          case Binary.Operator.LessThan:
            result.Operator = BinaryOperatorType.LessThan;
            break;
          case Binary.Operator.GreaterThan:
            result.Operator = BinaryOperatorType.GreaterThan;
            break;
          case Binary.Operator.LessThanOrEqual:
            result.Operator = BinaryOperatorType.LessThanOrEqual;
            break;
          case Binary.Operator.GreaterThanOrEqual:
            result.Operator = BinaryOperatorType.GreaterThanOrEqual;
            break;
          case Binary.Operator.Equality:
            result.Operator = BinaryOperatorType.Equality;
            break;
          case Binary.Operator.Inequality:
            result.Operator = BinaryOperatorType.InEquality;
            break;
          case Binary.Operator.BitwiseAnd:
            result.Operator = BinaryOperatorType.BitwiseAnd;
            break;
          case Binary.Operator.ExclusiveOr:
            result.Operator = BinaryOperatorType.ExclusiveOr;
            break;
          case Binary.Operator.BitwiseOr:
            result.Operator = BinaryOperatorType.BitwiseOr;
            break;
          case Binary.Operator.LogicalAnd:
            result.Operator = BinaryOperatorType.ConditionalAnd;
            break;
          case Binary.Operator.LogicalOr:
            result.Operator = BinaryOperatorType.ConditionalOr;
            break;
        }
        
        if (binaryExpression.Left != null)
          result.AddChild((Expression)binaryExpression.Left.Accept(this), BinaryOperatorExpression.LeftRole);
        var location = LocationsBag.GetLocations(binaryExpression);
        if (location != null) {
          var r = BinaryOperatorExpression.GetOperatorRole(result.Operator);
          result.AddChild(new CSharpTokenNode(Convert(location [0]), r), r);
        }
        if (binaryExpression.Right != null)
          result.AddChild((Expression)binaryExpression.Right.Accept(this), BinaryOperatorExpression.RightRole);
        return result;
      }

      public override object Visit(Mono.CSharp.Nullable.NullCoalescingOperator nullCoalescingOperator)
      {
        var result = new BinaryOperatorExpression();
        result.Operator = BinaryOperatorType.NullCoalescing;
        if (nullCoalescingOperator.LeftExpression != null)
          result.AddChild((Expression)nullCoalescingOperator.LeftExpression.Accept(this), BinaryOperatorExpression.LeftRole);
        var location = LocationsBag.GetLocations(nullCoalescingOperator);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), BinaryOperatorExpression.NullCoalescingRole), BinaryOperatorExpression.NullCoalescingRole);
        if (nullCoalescingOperator.RightExpression != null)
          result.AddChild((Expression)nullCoalescingOperator.RightExpression.Accept(this), BinaryOperatorExpression.RightRole);
        return result;
      }

      public override object Visit(Conditional conditionalExpression)
      {
        var result = new ConditionalExpression();
        
        if (conditionalExpression.Expr != null)
          result.AddChild((Expression)conditionalExpression.Expr.Accept(this), Roles.Condition);
        var location = LocationsBag.GetLocations(conditionalExpression);
        
        result.AddChild(new CSharpTokenNode(Convert(conditionalExpression.Location), ConditionalExpression.QuestionMarkRole), ConditionalExpression.QuestionMarkRole);
        if (conditionalExpression.TrueExpr != null)
          result.AddChild((Expression)conditionalExpression.TrueExpr.Accept(this), ConditionalExpression.TrueRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), ConditionalExpression.ColonRole), ConditionalExpression.ColonRole);
        if (conditionalExpression.FalseExpr != null)
          result.AddChild((Expression)conditionalExpression.FalseExpr.Accept(this), ConditionalExpression.FalseRole);
        return result;
      }

      void AddParameter(AstNode parent, AParametersCollection parameters)
      {
        if (parameters == null)
          return;
        var paramLocation = LocationsBag.GetLocations(parameters);
        
        for (int i = 0; i < parameters.Count; i++) {
          var p = (Parameter)parameters.FixedParameters [i];
          if (p == null)
            continue;
          var location = LocationsBag.GetLocations(p);
          var parameterDeclarationExpression = new ParameterDeclaration();
          AddAttributeSection(parameterDeclarationExpression, p);
          switch (p.ModFlags) {
            case Parameter.Modifier.OUT:
              parameterDeclarationExpression.ParameterModifier = ParameterModifier.Out;
              if (location != null)
                parameterDeclarationExpression.AddChild(new CSharpTokenNode(Convert(location [0]), ParameterDeclaration.OutModifierRole), ParameterDeclaration.OutModifierRole);
              break;
            case Parameter.Modifier.REF:
              parameterDeclarationExpression.ParameterModifier = ParameterModifier.Ref;
              if (location != null)
                parameterDeclarationExpression.AddChild(new CSharpTokenNode(Convert(location [0]), ParameterDeclaration.RefModifierRole), ParameterDeclaration.RefModifierRole);
              break;
            case Parameter.Modifier.PARAMS:
              parameterDeclarationExpression.ParameterModifier = ParameterModifier.Params;
              if (location != null)
                parameterDeclarationExpression.AddChild(new CSharpTokenNode(Convert(location [0]), ParameterDeclaration.ParamsModifierRole), ParameterDeclaration.ParamsModifierRole);
              break;
            default:
              if (p.HasExtensionMethodModifier) {
                parameterDeclarationExpression.ParameterModifier = ParameterModifier.This;
                if (location != null) {
                  parameterDeclarationExpression.AddChild(new CSharpTokenNode(Convert(location [0]), ParameterDeclaration.ThisModifierRole), ParameterDeclaration.ThisModifierRole);
                }
              }
              break;
          }
          if (p.TypeExpression != null) // lambdas may have no types (a, b) => ...
            parameterDeclarationExpression.AddChild(ConvertToType(p.TypeExpression), Roles.Type);
          if (p.Name != null)
            parameterDeclarationExpression.AddChild(Identifier.Create(p.Name, Convert(p.Location)), Roles.Identifier);
          if (p.HasDefaultValue) {
            if (location != null && location.Count > 1)
              parameterDeclarationExpression.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.Assign), Roles.Assign);
            parameterDeclarationExpression.AddChild((Expression)p.DefaultValue.Accept(this), Roles.Expression);
          }
          parent.AddChild(parameterDeclarationExpression, Roles.Parameter);
          if (paramLocation != null && i < paramLocation.Count) {
            parent.AddChild(new CSharpTokenNode(Convert(paramLocation [i]), Roles.Comma), Roles.Comma);
          }
        }
      }

      void AddTypeParameters(AstNode parent, MemberName memberName)
      {
        if (memberName == null || memberName.TypeParameters == null)
          return;
        var chevronLocs = LocationsBag.GetLocations(memberName.TypeParameters);
        if (chevronLocs != null)
          parent.AddChild(new CSharpTokenNode(Convert(chevronLocs [chevronLocs.Count - 2]), Roles.LChevron), Roles.LChevron);
        for (int i = 0; i < memberName.TypeParameters.Count; i++) {
          if (chevronLocs != null && i > 0 && i - 1 < chevronLocs.Count)
            parent.AddChild(new CSharpTokenNode(Convert(chevronLocs [i - 1]), Roles.Comma), Roles.Comma);
          var arg = memberName.TypeParameters [i];
          if (arg == null)
            continue;
          var tp = new TypeParameterDeclaration();
          
          List<Location> varianceLocation;
          switch (arg.Variance) {
            case Variance.Contravariant:
              tp.Variance = VarianceModifier.Contravariant;
              varianceLocation = LocationsBag.GetLocations(arg);
              if (varianceLocation != null)
                tp.AddChild(new CSharpTokenNode(Convert(varianceLocation [0]), TypeParameterDeclaration.InVarianceKeywordRole), TypeParameterDeclaration.InVarianceKeywordRole);
              break;
            case Variance.Covariant:
              tp.Variance = VarianceModifier.Covariant;
              varianceLocation = LocationsBag.GetLocations(arg);
              if (varianceLocation != null)
                tp.AddChild(new CSharpTokenNode(Convert(varianceLocation [0]), TypeParameterDeclaration.OutVarianceKeywordRole), TypeParameterDeclaration.OutVarianceKeywordRole);
              break;
            default:
              tp.Variance = VarianceModifier.Invariant;
              break;
              
          }
          
          AddAttributeSection(tp, arg.OptAttributes);

          switch (arg.Variance) {
            case Variance.Covariant:
              tp.Variance = VarianceModifier.Covariant;
              break;
            case Variance.Contravariant:
              tp.Variance = VarianceModifier.Contravariant;
              break;
          }
          tp.AddChild(Identifier.Create(arg.Name, Convert(arg.Location)), Roles.Identifier);
          parent.AddChild(tp, Roles.TypeParameter);
        }
        if (chevronLocs != null)
          parent.AddChild(new CSharpTokenNode(Convert(chevronLocs [chevronLocs.Count - 1]), Roles.RChevron), Roles.RChevron);
      }

      void AddTypeArguments(AstNode parent, MemberName memberName)
      {
        if (memberName == null || memberName.TypeParameters == null)
          return;
        var chevronLocs = LocationsBag.GetLocations(memberName.TypeParameters);
        if (chevronLocs != null)
          parent.AddChild(new CSharpTokenNode(Convert(chevronLocs [chevronLocs.Count - 2]), Roles.LChevron), Roles.LChevron);
        
        for (int i = 0; i < memberName.TypeParameters.Count; i++) {
          var arg = memberName.TypeParameters [i];
          if (arg == null)
            continue;
          parent.AddChild(ConvertToType(arg), Roles.TypeArgument);
          if (chevronLocs != null && i < chevronLocs.Count - 2)
            parent.AddChild(new CSharpTokenNode(Convert(chevronLocs [i]), Roles.Comma), Roles.Comma);
        }
        
        if (chevronLocs != null)
          parent.AddChild(new CSharpTokenNode(Convert(chevronLocs [chevronLocs.Count - 1]), Roles.RChevron), Roles.RChevron);
      }

      void AddTypeArguments(AstNode parent, ATypeNameExpression memberName)
      {
        if (memberName == null || !memberName.HasTypeArguments)
          return;
        var chevronLocs = LocationsBag.GetLocations(memberName.TypeArguments);
        if (chevronLocs != null)
          parent.AddChild(new CSharpTokenNode(Convert(chevronLocs [chevronLocs.Count - 2]), Roles.LChevron), Roles.LChevron);
        
        for (int i = 0; i < memberName.TypeArguments.Count; i++) {
          var arg = memberName.TypeArguments.Args [i];
          if (arg == null)
            continue;
          parent.AddChild(ConvertToType(arg), Roles.TypeArgument);
          if (chevronLocs != null && i < chevronLocs.Count - 2)
            parent.AddChild(new CSharpTokenNode(Convert(chevronLocs [i]), Roles.Comma), Roles.Comma);
        }
        
        if (chevronLocs != null)
          parent.AddChild(new CSharpTokenNode(Convert(chevronLocs [chevronLocs.Count - 1]), Roles.RChevron), Roles.RChevron);
      }

      void AddConstraints(AstNode parent, TypeParameters d)
      {
        if (d == null)
          return;
        for (int i = 0; i < d.Count; i++) {
          var typeParameter = d [i];
          if (typeParameter == null)
            continue;
          var c = typeParameter.Constraints;
          if (c == null)
            continue;
          var location = LocationsBag.GetLocations(c);
          var constraint = new Constraint();
          constraint.AddChild(new CSharpTokenNode(Convert(c.Location), Roles.WhereKeyword), Roles.WhereKeyword);
          constraint.AddChild(new SimpleType(Identifier.Create(c.TypeParameter.Value, Convert(c.TypeParameter.Location))), Roles.ConstraintTypeParameter);
          if (location != null)
            constraint.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Colon), Roles.Colon);
          var commaLocs = LocationsBag.GetLocations(c.ConstraintExpressions);
          int curComma = 0;
          if (c.ConstraintExpressions != null) {
            foreach (var expr in c.ConstraintExpressions) {
              constraint.AddChild(ConvertToType(expr), Roles.BaseType);
              var sce = expr as SpecialContraintExpr;
              if (sce != null) {
                switch (sce.Constraint) {
                  case SpecialConstraint.Class:
                    break;
                  case SpecialConstraint.Struct:
                    break;
                  case SpecialConstraint.Constructor:
                    var bl = LocationsBag.GetLocations(expr);
                    if (bl != null) {
                      constraint.AddChild(new CSharpTokenNode(Convert(bl [0]), Roles.LPar), Roles.LPar);
                      constraint.AddChild(new CSharpTokenNode(Convert(bl [1]), Roles.RPar), Roles.RPar);
                    }
                    break;
                }
              }

              if (commaLocs != null && curComma < commaLocs.Count)
                constraint.AddChild(new CSharpTokenNode(Convert(commaLocs [curComma++]), Roles.Comma), Roles.Comma);
            }
          }
          
          // We need to sort the constraints by position; as they might be in a different order than the type parameters
          AstNode prevSibling = parent.LastChild;
          while (prevSibling.StartLocation > constraint.StartLocation && prevSibling.PrevSibling != null)
            prevSibling = prevSibling.PrevSibling;
          parent.InsertChildAfter(prevSibling, constraint, Roles.Constraint);
        }
      }

      Expression ConvertArgument(Argument arg)
      {
        var na = arg as NamedArgument;
        if (na != null) {
          var newArg = new NamedArgumentExpression();
          newArg.AddChild(Identifier.Create(na.Name, Convert(na.Location)), Roles.Identifier);
          
          var loc = LocationsBag.GetLocations(na);
          if (loc != null)
            newArg.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.Colon), Roles.Colon);
          
          if (arg.ArgType == Argument.AType.Out || arg.ArgType == Argument.AType.Ref) {
            var direction = new DirectionExpression();
            direction.FieldDirection = arg.ArgType == Argument.AType.Out ? FieldDirection.Out : FieldDirection.Ref;
            var argLocation = LocationsBag.GetLocations(arg);
            if (argLocation != null) {
              var r = arg.ArgType == Argument.AType.Out ? DirectionExpression.OutKeywordRole : DirectionExpression.RefKeywordRole;
              direction.AddChild(new CSharpTokenNode(Convert(argLocation [0]), r), r);
            }
            direction.AddChild((Expression)arg.Expr.Accept(this), Roles.Expression);
            newArg.AddChild(direction, Roles.Expression);
          } else {
            newArg.AddChild(na.Expr != null ? (Expression)na.Expr.Accept(this) : new ErrorExpression("Named argument expression parse error"), Roles.Expression);
          }
          return newArg;
        }
        
        if (arg.ArgType == Argument.AType.Out || arg.ArgType == Argument.AType.Ref) {
          var direction = new DirectionExpression();
          direction.FieldDirection = arg.ArgType == Argument.AType.Out ? FieldDirection.Out : FieldDirection.Ref;
          var argLocation = LocationsBag.GetLocations(arg);
          if (argLocation != null) {
            var r = arg.ArgType == Argument.AType.Out ? DirectionExpression.OutKeywordRole : DirectionExpression.RefKeywordRole;
            direction.AddChild(new CSharpTokenNode(Convert(argLocation [0]), r), r);
          }
          direction.AddChild((Expression)arg.Expr.Accept(this), Roles.Expression);
          return direction;
        }
        
        return (Expression)arg.Expr.Accept(this);
      }

      void AddArguments(AstNode parent, Arguments args)
      {
        if (args == null)
          return;
        
        var commaLocations = LocationsBag.GetLocations(args);
        for (int i = 0; i < args.Count; i++) {
          parent.AddChild(ConvertArgument(args [i]), Roles.Argument);
          if (commaLocations != null && i < commaLocations.Count) {
            parent.AddChild(new CSharpTokenNode(Convert(commaLocations [i]), Roles.Comma), Roles.Comma);
          }
        }
        if (commaLocations != null && commaLocations.Count > args.Count)
          parent.AddChild(new CSharpTokenNode(Convert(commaLocations [args.Count]), Roles.Comma), Roles.Comma);
      }

      public override object Visit(Invocation invocationExpression)
      {
        var result = new InvocationExpression();
        var location = LocationsBag.GetLocations(invocationExpression);
        if (invocationExpression.Exp != null)
          result.AddChild((Expression)invocationExpression.Exp.Accept(this), Roles.TargetExpression);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        AddArguments(result, invocationExpression.Arguments);
        
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        return result;
      }

      public override object Visit(New newExpression)
      {
        var result = new ObjectCreateExpression();
        var location = LocationsBag.GetLocations(newExpression);
        result.AddChild(new CSharpTokenNode(Convert(newExpression.Location), ObjectCreateExpression.NewKeywordRole), ObjectCreateExpression.NewKeywordRole);
        
        if (newExpression.TypeRequested != null)
          result.AddChild(ConvertToType(newExpression.TypeRequested), Roles.Type);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        AddArguments(result, newExpression.Arguments);
        
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        
        return result;
      }

      public override object Visit(NewAnonymousType newAnonymousType)
      {
        var result = new AnonymousTypeCreateExpression();
        var location = LocationsBag.GetLocations(newAnonymousType);
        result.AddChild(new CSharpTokenNode(Convert(newAnonymousType.Location), ObjectCreateExpression.NewKeywordRole), ObjectCreateExpression.NewKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LBrace), Roles.LBrace);
        if (newAnonymousType.Parameters != null) {
          foreach (var par in newAnonymousType.Parameters) {
            if (par == null)
              continue;
            var parLocation = LocationsBag.GetLocations(par);
            
            if (parLocation == null) {
              if (par.Expr != null)
                result.AddChild((Expression)par.Expr.Accept(this), Roles.Expression);
            } else {
              var namedExpression = new NamedExpression();
              namedExpression.AddChild(Identifier.Create(par.Name, Convert(par.Location)), Roles.Identifier);
              namedExpression.AddChild(new CSharpTokenNode(Convert(parLocation [0]), Roles.Assign), Roles.Assign);
              if (par.Expr != null)
                namedExpression.AddChild((Expression)par.Expr.Accept(this), Roles.Expression);
              result.AddChild(namedExpression, Roles.Expression);
            }
          }
        }
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RBrace), Roles.RBrace);
        return result;
      }

      ArrayInitializerExpression ConvertCollectionOrObjectInitializers(CollectionOrObjectInitializers minit)
      {
        if (minit == null)
          return null;
        var init = new ArrayInitializerExpression();
        AddConvertCollectionOrObjectInitializers(init, minit);
        return init;
      }

      void AddConvertCollectionOrObjectInitializers(Expression init, CollectionOrObjectInitializers minit)
      {
        var initLoc = LocationsBag.GetLocations(minit);
        var commaLoc = LocationsBag.GetLocations(minit.Initializers);
        int curComma = 0;
        init.AddChild(new CSharpTokenNode(Convert(minit.Location), Roles.LBrace), Roles.LBrace);
        foreach (var expr in minit.Initializers) {
          var collectionInit = expr as CollectionElementInitializer;
          if (collectionInit != null) {
            AstNode parent;
            // For ease of use purposes in the resolver the ast representation
            // of { a, b, c }  is { {a}, {b}, {c} } - but the generated ArrayInitializerExpression
            // can be identified by expr.IsSingleElement.
            if (!collectionInit.IsSingle) {
              parent = new ArrayInitializerExpression();
              parent.AddChild(new CSharpTokenNode(Convert(collectionInit.Location), Roles.LBrace), Roles.LBrace);
            } else {
              parent = ArrayInitializerExpression.CreateSingleElementInitializer();
            }

            if (collectionInit.Arguments != null) {
              for (int i = 0; i < collectionInit.Arguments.Count; i++) {
                var arg = collectionInit.Arguments [i] as CollectionElementInitializer.ElementInitializerArgument;
                if (arg == null || arg.Expr == null)
                  continue;
                parent.AddChild(
                  (Expression)arg.Expr.Accept(this),
                  Roles.Expression
                );
              }
            }

            if (!collectionInit.IsSingle) {
              var braceLocs = LocationsBag.GetLocations(expr);
              if (braceLocs != null)
                parent.AddChild(new CSharpTokenNode(Convert(braceLocs [0]), Roles.RBrace), Roles.RBrace);
            }
            init.AddChild((ArrayInitializerExpression)parent, Roles.Expression);
          } else {
            var eleInit = expr as ElementInitializer;
            if (eleInit != null) {
              var nexpr = new NamedExpression();
              nexpr.AddChild(
                Identifier.Create(eleInit.Name, Convert(eleInit.Location)),
                Roles.Identifier
              );
              var assignLoc = LocationsBag.GetLocations(eleInit);
              if (assignLoc != null)
                nexpr.AddChild(new CSharpTokenNode(Convert(assignLoc [0]), Roles.Assign), Roles.Assign);
              if (eleInit.Source != null) {
                var colInit = eleInit.Source as CollectionOrObjectInitializers;
                if (colInit != null) {
                  var arrInit = new ArrayInitializerExpression();
                  AddConvertCollectionOrObjectInitializers(
                    arrInit,
                    colInit
                  );
                  nexpr.AddChild(arrInit, Roles.Expression);
                } else {
                  nexpr.AddChild((Expression)eleInit.Source.Accept(this), Roles.Expression);
                }
              }

              init.AddChild(nexpr, Roles.Expression);
            }
          }
          if (commaLoc != null && curComma < commaLoc.Count)
            init.AddChild(new CSharpTokenNode(Convert(commaLoc [curComma++]), Roles.Comma), Roles.Comma);
        }

        if (initLoc != null) {
          if (initLoc.Count == 2) // optional comma
            init.AddChild(new CSharpTokenNode(Convert(initLoc [0]), Roles.Comma), Roles.Comma);
          init.AddChild(new CSharpTokenNode(Convert(initLoc [initLoc.Count - 1]), Roles.RBrace), Roles.RBrace);
        }
      }

      public override object Visit(NewInitialize newInitializeExpression)
      {
        var result = new ObjectCreateExpression();
        result.AddChild(new CSharpTokenNode(Convert(newInitializeExpression.Location), ObjectCreateExpression.NewKeywordRole), ObjectCreateExpression.NewKeywordRole);
        
        if (newInitializeExpression.TypeRequested != null)
          result.AddChild(ConvertToType(newInitializeExpression.TypeRequested), Roles.Type);
        
        var location = LocationsBag.GetLocations(newInitializeExpression);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        AddArguments(result, newInitializeExpression.Arguments);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        
        var init = ConvertCollectionOrObjectInitializers(newInitializeExpression.Initializers);
        if (init != null)
          result.AddChild(init, ObjectCreateExpression.InitializerRole);
        
        return result;
      }

      public override object Visit(ArrayCreation arrayCreationExpression)
      {
        var result = new ArrayCreateExpression();
        
        var location = LocationsBag.GetLocations(arrayCreationExpression);
        result.AddChild(new CSharpTokenNode(Convert(arrayCreationExpression.Location), ArrayCreateExpression.NewKeywordRole), ArrayCreateExpression.NewKeywordRole);
        if (arrayCreationExpression.TypeExpression != null)
          result.AddChild(ConvertToType(arrayCreationExpression.TypeExpression), Roles.Type);
        
        var next = arrayCreationExpression.Rank;
        if (arrayCreationExpression.Arguments != null) {
          // skip first array rank.
          next = next.Next;
          
          if (location != null)
            result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LBracket), Roles.LBracket);
          
          var commaLocations = LocationsBag.GetLocations(arrayCreationExpression.Arguments);
          for (int i = 0; i < arrayCreationExpression.Arguments.Count; i++) {
            var arg = arrayCreationExpression.Arguments [i];
            if (arg != null)
              result.AddChild((Expression)arg.Accept(this), Roles.Argument);
            if (commaLocations != null && i < commaLocations.Count)
              result.AddChild(new CSharpTokenNode(Convert(commaLocations [i]), Roles.Comma), Roles.Comma);
          }
          if (location != null && location.Count > 1)
            result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RBracket), Roles.RBracket);
          
        }
        
        while (next != null) {
          var spec = new ArraySpecifier(next.Dimension);
          var loc = LocationsBag.GetLocations(next);
          spec.AddChild(new CSharpTokenNode(Convert(next.Location), Roles.LBracket), Roles.LBracket);
          result.AddChild(spec, ArrayCreateExpression.AdditionalArraySpecifierRole);
          if (loc != null)
            result.AddChild(new CSharpTokenNode(Convert(loc [0]), Roles.RBracket), Roles.RBracket);
          next = next.Next;
        }
        
        if (arrayCreationExpression.Initializers != null) {
          var initLocation = LocationsBag.GetLocations(arrayCreationExpression.Initializers);
          var initializer = new ArrayInitializerExpression();
          
          initializer.AddChild(new CSharpTokenNode(Convert(arrayCreationExpression.Initializers.Location), Roles.LBrace), Roles.LBrace);
          var commaLocations = LocationsBag.GetLocations(arrayCreationExpression.Initializers.Elements);
          for (int i = 0; i < arrayCreationExpression.Initializers.Count; i++) {
            var init = arrayCreationExpression.Initializers [i];
            if (init == null)
              continue;
            initializer.AddChild((Expression)init.Accept(this), Roles.Expression);
            if (commaLocations != null && i < commaLocations.Count) {
              initializer.AddChild(new CSharpTokenNode(Convert(commaLocations [i]), Roles.Comma), Roles.Comma);
            }
          }
          if (initLocation != null) {
            if (initLocation.Count == 2) // optional comma
              initializer.AddChild(new CSharpTokenNode(Convert(initLocation [0]), Roles.Comma), Roles.Comma);
            initializer.AddChild(new CSharpTokenNode(Convert(initLocation [initLocation.Count - 1]), Roles.RBrace), Roles.RBrace);
          }
          result.AddChild(initializer, ArrayCreateExpression.InitializerRole);
        }
        
        return result;
      }

      public override object Visit(This thisExpression)
      {
        var result = new ThisReferenceExpression();
        result.Location = Convert(thisExpression.Location);
        return result;
      }

      public override object Visit(ArglistAccess argListAccessExpression)
      {
        var result = new UndocumentedExpression {
          UndocumentedExpressionType = UndocumentedExpressionType.ArgListAccess
        };
        result.AddChild(new CSharpTokenNode(Convert(argListAccessExpression.Location), UndocumentedExpression.ArglistKeywordRole), UndocumentedExpression.ArglistKeywordRole);
        return result;
      }

      #region Undocumented expressions

      public override object Visit(Arglist argListExpression)
      {
        var result = new UndocumentedExpression { UndocumentedExpressionType = UndocumentedExpressionType.ArgList };
        result.AddChild(new CSharpTokenNode(Convert(argListExpression.Location), UndocumentedExpression.ArglistKeywordRole), UndocumentedExpression.ArglistKeywordRole);
        var location = LocationsBag.GetLocations(argListExpression);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        
        AddArguments(result, argListExpression.Arguments);
        
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        return result;
      }

      public override object Visit(MakeRefExpr makeRefExpr)
      {
        var result = new UndocumentedExpression { UndocumentedExpressionType = UndocumentedExpressionType.MakeRef };
        result.AddChild(new CSharpTokenNode(Convert(makeRefExpr.Location), UndocumentedExpression.MakerefKeywordRole), UndocumentedExpression.MakerefKeywordRole);
        var location = LocationsBag.GetLocations(makeRefExpr);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        if (makeRefExpr.Expr != null)
          result.AddChild((Expression)makeRefExpr.Expr.Accept(this), Roles.Argument);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        return result;
      }

      public override object Visit(RefTypeExpr refTypeExpr)
      {
        var result = new UndocumentedExpression { UndocumentedExpressionType = UndocumentedExpressionType.RefType };
        result.AddChild(new CSharpTokenNode(Convert(refTypeExpr.Location), UndocumentedExpression.ReftypeKeywordRole), UndocumentedExpression.ReftypeKeywordRole);
        var location = LocationsBag.GetLocations(refTypeExpr);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        
        if (refTypeExpr.Expr != null)
          result.AddChild((Expression)refTypeExpr.Expr.Accept(this), Roles.Argument);
        
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        return result;
      }

      public override object Visit(RefValueExpr refValueExpr)
      {
        var result = new UndocumentedExpression { UndocumentedExpressionType = UndocumentedExpressionType.RefValue };
        result.AddChild(new CSharpTokenNode(Convert(refValueExpr.Location), UndocumentedExpression.RefvalueKeywordRole), UndocumentedExpression.RefvalueKeywordRole);
        var location = LocationsBag.GetLocations(refValueExpr);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        
        
        if (refValueExpr.Expr != null)
          result.AddChild((Expression)refValueExpr.Expr.Accept(this), Roles.Argument);

        if (refValueExpr.FullNamedExpression != null)
          result.AddChild((Expression)refValueExpr.FullNamedExpression.Accept(this), Roles.Argument);
        
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        return result;
      }

      #endregion

      public override object Visit(TypeOf typeOfExpression)
      {
        var result = new TypeOfExpression();
        var location = LocationsBag.GetLocations(typeOfExpression);
        result.AddChild(new CSharpTokenNode(Convert(typeOfExpression.Location), TypeOfExpression.TypeofKeywordRole), TypeOfExpression.TypeofKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        if (typeOfExpression.TypeExpression != null)
          result.AddChild(ConvertToType(typeOfExpression.TypeExpression), Roles.Type);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        return result;
      }

      public override object Visit(SizeOf sizeOfExpression)
      {
        var result = new SizeOfExpression();
        var location = LocationsBag.GetLocations(sizeOfExpression);
        result.AddChild(new CSharpTokenNode(Convert(sizeOfExpression.Location), SizeOfExpression.SizeofKeywordRole), SizeOfExpression.SizeofKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        if (sizeOfExpression.TypeExpression != null)
          result.AddChild(ConvertToType(sizeOfExpression.TypeExpression), Roles.Type);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        return result;
      }

      public override object Visit(CheckedExpr checkedExpression)
      {
        var result = new CheckedExpression();
        var location = LocationsBag.GetLocations(checkedExpression);
        result.AddChild(new CSharpTokenNode(Convert(checkedExpression.Location), CheckedExpression.CheckedKeywordRole), CheckedExpression.CheckedKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        if (checkedExpression.Expr != null)
          result.AddChild((Expression)checkedExpression.Expr.Accept(this), Roles.Expression);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        return result;
      }

      public override object Visit(UnCheckedExpr uncheckedExpression)
      {
        var result = new UncheckedExpression();
        var location = LocationsBag.GetLocations(uncheckedExpression);
        result.AddChild(new CSharpTokenNode(Convert(uncheckedExpression.Location), UncheckedExpression.UncheckedKeywordRole), UncheckedExpression.UncheckedKeywordRole);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.LPar), Roles.LPar);
        if (uncheckedExpression.Expr != null)
          result.AddChild((Expression)uncheckedExpression.Expr.Accept(this), Roles.Expression);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.RPar), Roles.RPar);
        return result;
      }

      public override object Visit(ElementAccess elementAccessExpression)
      {
        var result = new IndexerExpression();
        var location = LocationsBag.GetLocations(elementAccessExpression);
        
        if (elementAccessExpression.Expr != null)
          result.AddChild((Expression)elementAccessExpression.Expr.Accept(this), Roles.TargetExpression);
        result.AddChild(new CSharpTokenNode(Convert(elementAccessExpression.Location), Roles.LBracket), Roles.LBracket);
        AddArguments(result, elementAccessExpression.Arguments);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.RBracket), Roles.RBracket);
        return result;
      }

      public override object Visit(BaseThis baseAccessExpression)
      {
        var result = new BaseReferenceExpression();
        result.Location = Convert(baseAccessExpression.Location);
        return result;
      }

      public override object Visit(StackAlloc stackAllocExpression)
      {
        var result = new StackAllocExpression();
        
        var location = LocationsBag.GetLocations(stackAllocExpression);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), StackAllocExpression.StackallocKeywordRole), StackAllocExpression.StackallocKeywordRole);
        if (stackAllocExpression.TypeExpression != null)
          result.AddChild(ConvertToType(stackAllocExpression.TypeExpression), Roles.Type);
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), Roles.LBracket), Roles.LBracket);
        if (stackAllocExpression.CountExpression != null)
          result.AddChild((Expression)stackAllocExpression.CountExpression.Accept(this), Roles.Expression);
        if (location != null && location.Count > 2)
          result.AddChild(new CSharpTokenNode(Convert(location [2]), Roles.RBracket), Roles.RBracket);
        return result;
      }

      public override object Visit(SimpleAssign simpleAssign)
      {
        var result = new AssignmentExpression();
        
        result.Operator = AssignmentOperatorType.Assign;
        if (simpleAssign.Target != null)
          result.AddChild((Expression)simpleAssign.Target.Accept(this), AssignmentExpression.LeftRole);
        var location = LocationsBag.GetLocations(simpleAssign);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), AssignmentExpression.AssignRole), AssignmentExpression.AssignRole);
        if (simpleAssign.Source != null) {
          result.AddChild((Expression)simpleAssign.Source.Accept(this), AssignmentExpression.RightRole);
        }
        return result;
      }

      public override object Visit(CompoundAssign compoundAssign)
      {
        var result = new AssignmentExpression();
        switch (compoundAssign.Op) {
          case Binary.Operator.Multiply:
            result.Operator = AssignmentOperatorType.Multiply;
            break;
          case Binary.Operator.Division:
            result.Operator = AssignmentOperatorType.Divide;
            break;
          case Binary.Operator.Modulus:
            result.Operator = AssignmentOperatorType.Modulus;
            break;
          case Binary.Operator.Addition:
            result.Operator = AssignmentOperatorType.Add;
            break;
          case Binary.Operator.Subtraction:
            result.Operator = AssignmentOperatorType.Subtract;
            break;
          case Binary.Operator.LeftShift:
            result.Operator = AssignmentOperatorType.ShiftLeft;
            break;
          case Binary.Operator.RightShift:
            result.Operator = AssignmentOperatorType.ShiftRight;
            break;
          case Binary.Operator.BitwiseAnd:
            result.Operator = AssignmentOperatorType.BitwiseAnd;
            break;
          case Binary.Operator.BitwiseOr:
            result.Operator = AssignmentOperatorType.BitwiseOr;
            break;
          case Binary.Operator.ExclusiveOr:
            result.Operator = AssignmentOperatorType.ExclusiveOr;
            break;
        }
        
        if (compoundAssign.Target != null)
          result.AddChild((Expression)compoundAssign.Target.Accept(this), AssignmentExpression.LeftRole);
        var location = LocationsBag.GetLocations(compoundAssign);
        if (location != null) {
          var r = AssignmentExpression.GetOperatorRole(result.Operator);
          result.AddChild(new CSharpTokenNode(Convert(location [0]), r), r);
        }
        if (compoundAssign.Source != null)
          result.AddChild((Expression)compoundAssign.Source.Accept(this), AssignmentExpression.RightRole);
        return result;
      }

      public override object Visit(Mono.CSharp.AnonymousMethodExpression anonymousMethodExpression)
      {
        var result = new AnonymousMethodExpression();
        var location = LocationsBag.GetLocations(anonymousMethodExpression);
        int l = 0;
        if (anonymousMethodExpression.IsAsync) {
          result.IsAsync = true;
          result.AddChild(new CSharpTokenNode(Convert(location [l++]), AnonymousMethodExpression.AsyncModifierRole), AnonymousMethodExpression.AsyncModifierRole);
        }
        if (location != null) {
          result.AddChild(new CSharpTokenNode(Convert(location [l++]), AnonymousMethodExpression.DelegateKeywordRole), AnonymousMethodExpression.DelegateKeywordRole);
          
          if (location.Count > l) {
            result.HasParameterList = true;
            result.AddChild(new CSharpTokenNode(Convert(location [l++]), Roles.LPar), Roles.LPar);
            AddParameter(result, anonymousMethodExpression.Parameters);
            result.AddChild(new CSharpTokenNode(Convert(location [l++]), Roles.RPar), Roles.RPar);
          }
        }
        if (anonymousMethodExpression.Block != null)
          result.AddChild((BlockStatement)anonymousMethodExpression.Block.Accept(this), Roles.Body);
        return result;
      }

      public override object Visit(Mono.CSharp.LambdaExpression lambdaExpression)
      {
        var result = new LambdaExpression();
        var location = LocationsBag.GetLocations(lambdaExpression);
        int l = 0;
        if (lambdaExpression.IsAsync) {
          result.IsAsync = true;
          result.AddChild(new CSharpTokenNode(Convert(location [l++]), LambdaExpression.AsyncModifierRole), LambdaExpression.AsyncModifierRole);
        }
        if (location == null || location.Count == l + 1) {
          if (lambdaExpression.Block != null)
            AddParameter(result, lambdaExpression.Parameters);
          if (location != null)
            result.AddChild(new CSharpTokenNode(Convert(location [l++]), LambdaExpression.ArrowRole), LambdaExpression.ArrowRole);
        } else {
          result.AddChild(new CSharpTokenNode(Convert(location [l++]), Roles.LPar), Roles.LPar);
          if (lambdaExpression.Block != null)
            AddParameter(result, lambdaExpression.Parameters);
          if (location != null) {
            result.AddChild(new CSharpTokenNode(Convert(location [l++]), Roles.RPar), Roles.RPar);
            result.AddChild(new CSharpTokenNode(Convert(location [l++]), LambdaExpression.ArrowRole), LambdaExpression.ArrowRole);
          }
        }
        if (lambdaExpression.Block != null) {
          if (lambdaExpression.Block.IsCompilerGenerated) {
            var generatedReturn = (ContextualReturn)lambdaExpression.Block.Statements [0];
            result.AddChild((AstNode)generatedReturn.Expr.Accept(this), LambdaExpression.BodyRole);
          } else {
            result.AddChild((AstNode)lambdaExpression.Block.Accept(this), LambdaExpression.BodyRole);
          }
        }
        return result;
      }

      public override object Visit(ConstInitializer constInitializer)
      {
        return constInitializer.Expr.Accept(this);
      }

      public override object Visit(ArrayInitializer arrayInitializer)
      {
        var result = new ArrayInitializerExpression();
        var location = LocationsBag.GetLocations(arrayInitializer);
        result.AddChild(new CSharpTokenNode(Convert(arrayInitializer.Location), Roles.LBrace), Roles.LBrace);
        var commaLocations = LocationsBag.GetLocations(arrayInitializer.Elements);
        for (int i = 0; i < arrayInitializer.Count; i++) {
          var init = arrayInitializer [i];
          if (init == null)
            continue;
          result.AddChild((Expression)init.Accept(this), Roles.Expression);
          if (commaLocations != null && i < commaLocations.Count)
            result.AddChild(new CSharpTokenNode(Convert(commaLocations [i]), Roles.Comma), Roles.Comma);
        }
        
        if (location != null) {
          if (location.Count == 2) // optional comma
            result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Comma), Roles.Comma);
          result.AddChild(new CSharpTokenNode(Convert(location [location.Count - 1]), Roles.RBrace), Roles.RBrace);
        }
        return result;
      }

      #endregion

      #region LINQ expressions

      QueryOrderClause currentQueryOrderClause;

      public override object Visit(Mono.CSharp.Linq.QueryExpression queryExpression)
      {
        var oldQueryOrderClause = currentQueryOrderClause;
        try {
          currentQueryOrderClause = null;
          var result = new QueryExpression();
          
          var currentClause = queryExpression.next;
          
          while (currentClause != null) {
            var clause = (QueryClause)currentClause.Accept(this);
            if (clause is QueryContinuationClause) {
              // insert preceding query at beginning of QueryContinuationClause
              clause.InsertChildAfter(null, result, QueryContinuationClause.PrecedingQueryRole);
              // create a new QueryExpression for the remaining query
              result = new QueryExpression();
            }
            if (clause != null) {
              result.AddChild(clause, QueryExpression.ClauseRole);
            }
            currentClause = currentClause.next;
          }
          
          return result;
        } finally {
          currentQueryOrderClause = oldQueryOrderClause;
        }
      }

      public override object Visit(Mono.CSharp.Linq.QueryStartClause queryExpression)
      {
        if (queryExpression.Expr == null) {
          var intoClause = new QueryContinuationClause();
          intoClause.AddChild(new CSharpTokenNode(Convert(queryExpression.Location), QueryContinuationClause.IntoKeywordRole), QueryContinuationClause.IntoKeywordRole);
          intoClause.AddChild(Identifier.Create(queryExpression.IntoVariable.Name, Convert(queryExpression.IntoVariable.Location)), Roles.Identifier);
          return intoClause;
        }
        
        var fromClause = new QueryFromClause();

        fromClause.AddChild(new CSharpTokenNode(Convert(queryExpression.Location), QueryFromClause.FromKeywordRole), QueryFromClause.FromKeywordRole);
        
        if (queryExpression.IdentifierType != null)
          fromClause.AddChild(ConvertToType(queryExpression.IdentifierType), Roles.Type);
        
        fromClause.AddChild(Identifier.Create(queryExpression.IntoVariable.Name, Convert(queryExpression.IntoVariable.Location)), Roles.Identifier);
        
        var location = LocationsBag.GetLocations(queryExpression);
        if (location != null)
          fromClause.AddChild(new CSharpTokenNode(Convert(location [0]), QueryFromClause.InKeywordRole), QueryFromClause.InKeywordRole);

        if (queryExpression.Expr != null)
          fromClause.AddChild((Expression)queryExpression.Expr.Accept(this), Roles.Expression);
        return fromClause;
      }

      public override object Visit(Mono.CSharp.Linq.SelectMany selectMany)
      {
        var fromClause = new QueryFromClause();

        fromClause.AddChild(new CSharpTokenNode(Convert(selectMany.Location), QueryFromClause.FromKeywordRole), QueryFromClause.FromKeywordRole);
        
        if (selectMany.IdentifierType != null)
          fromClause.AddChild(ConvertToType(selectMany.IdentifierType), Roles.Type);
        
        fromClause.AddChild(Identifier.Create(selectMany.IntoVariable.Name, Convert(selectMany.IntoVariable.Location)), Roles.Identifier);
        
        var location = LocationsBag.GetLocations(selectMany);
        if (location != null)
          fromClause.AddChild(new CSharpTokenNode(Convert(location [0]), QueryFromClause.InKeywordRole), QueryFromClause.InKeywordRole);

        if (selectMany.Expr != null)
          fromClause.AddChild((Expression)selectMany.Expr.Accept(this), Roles.Expression);
        return fromClause;
      }

      public override object Visit(Mono.CSharp.Linq.Select select)
      {
        var result = new QuerySelectClause();
        result.AddChild(new CSharpTokenNode(Convert(select.Location), QuerySelectClause.SelectKeywordRole), QuerySelectClause.SelectKeywordRole);
        if (select.Expr != null)
          result.AddChild((Expression)select.Expr.Accept(this), Roles.Expression);
        return result;
      }

      public override object Visit(Mono.CSharp.Linq.GroupBy groupBy)
      {
        var result = new QueryGroupClause();
        var location = LocationsBag.GetLocations(groupBy);
        result.AddChild(new CSharpTokenNode(Convert(groupBy.Location), QueryGroupClause.GroupKeywordRole), QueryGroupClause.GroupKeywordRole);
        if (groupBy.ElementSelector != null)
          result.AddChild((Expression)groupBy.ElementSelector.Accept(this), QueryGroupClause.ProjectionRole);
        if (location != null) {
          var byLoc = Convert(location[0]);
          if (byLoc.Line > 1 || byLoc.Column > 1)
            result.AddChild(new CSharpTokenNode(byLoc, QueryGroupClause.ByKeywordRole), QueryGroupClause.ByKeywordRole);
        }
        if (groupBy.Expr != null)
          result.AddChild((Expression)groupBy.Expr.Accept(this), QueryGroupClause.KeyRole);
        return result;
      }

      public override object Visit(Mono.CSharp.Linq.Let let)
      {
        var result = new QueryLetClause();
        var location = LocationsBag.GetLocations(let);
        
        result.AddChild(new CSharpTokenNode(Convert(let.Location), QueryLetClause.LetKeywordRole), QueryLetClause.LetKeywordRole);
        result.AddChild(Identifier.Create(let.IntoVariable.Name, Convert(let.IntoVariable.Location)), Roles.Identifier);
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), Roles.Assign), Roles.Assign);
        if (let.Expr != null)
          result.AddChild((Expression)let.Expr.Accept(this), Roles.Expression);
        return result;
      }

      public override object Visit(Mono.CSharp.Linq.Where where)
      {
        var result = new QueryWhereClause();
        result.AddChild(new CSharpTokenNode(Convert(where.Location), QueryWhereClause.WhereKeywordRole), QueryWhereClause.WhereKeywordRole);
        if (where.Expr != null)
          result.AddChild((Expression)where.Expr.Accept(this), Roles.Condition);
        return result;
      }

      public override object Visit(Mono.CSharp.Linq.Join join)
      {
        var result = new QueryJoinClause();
        var location = LocationsBag.GetLocations(join);
        result.AddChild(new CSharpTokenNode(Convert(join.Location), QueryJoinClause.JoinKeywordRole), QueryJoinClause.JoinKeywordRole);

        if (join.IdentifierType != null)
          result.AddChild(ConvertToType(join.IdentifierType), QueryJoinClause.TypeRole);

        result.AddChild(Identifier.Create(join.JoinVariable.Name, Convert(join.JoinVariable.Location)), QueryJoinClause.JoinIdentifierRole);

        if (join.IdentifierType != null)
          result.AddChild(ConvertToType(join.IdentifierType), QueryJoinClause.TypeRole);

        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), QueryJoinClause.InKeywordRole), QueryJoinClause.InKeywordRole);

        if (join.Expr != null)
          result.AddChild((Expression)join.Expr.Accept(this), QueryJoinClause.InExpressionRole);
        
        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), QueryJoinClause.OnKeywordRole), QueryJoinClause.OnKeywordRole);
        
        var outer = join.OuterSelector.Statements.FirstOrDefault() as ContextualReturn;
        if (outer != null)
          result.AddChild((Expression)outer.Expr.Accept(this), QueryJoinClause.OnExpressionRole);
        
        if (location != null && location.Count > 2)
          result.AddChild(new CSharpTokenNode(Convert(location [2]), QueryJoinClause.EqualsKeywordRole), QueryJoinClause.EqualsKeywordRole);
        
        var inner = join.InnerSelector.Statements.FirstOrDefault() as ContextualReturn;
        if (inner != null)
          result.AddChild((Expression)inner.Expr.Accept(this), QueryJoinClause.EqualsExpressionRole);
        
        return result;
      }

      public override object Visit(Mono.CSharp.Linq.GroupJoin groupJoin)
      {
        var result = new QueryJoinClause();
        var location = LocationsBag.GetLocations(groupJoin);
        result.AddChild(new CSharpTokenNode(Convert(groupJoin.Location), QueryJoinClause.JoinKeywordRole), QueryJoinClause.JoinKeywordRole);
        
        // mcs seems to have swapped IntoVariable with JoinVariable, so we'll swap it back here
        result.AddChild(Identifier.Create(groupJoin.IntoVariable.Name, Convert(groupJoin.IntoVariable.Location)), QueryJoinClause.JoinIdentifierRole);
        
        if (location != null)
          result.AddChild(new CSharpTokenNode(Convert(location [0]), QueryJoinClause.InKeywordRole), QueryJoinClause.InKeywordRole);

        if (groupJoin.Expr != null)
          result.AddChild((Expression)groupJoin.Expr.Accept(this), QueryJoinClause.InExpressionRole);

        if (location != null && location.Count > 1)
          result.AddChild(new CSharpTokenNode(Convert(location [1]), QueryJoinClause.OnKeywordRole), QueryJoinClause.OnKeywordRole);

        var outer = groupJoin.OuterSelector.Statements.FirstOrDefault() as ContextualReturn;
        if (outer != null)
          result.AddChild((Expression)outer.Expr.Accept(this), QueryJoinClause.OnExpressionRole);
        

        if (location != null && location.Count > 2)
          result.AddChild(new CSharpTokenNode(Convert(location [2]), QueryJoinClause.EqualsKeywordRole), QueryJoinClause.EqualsKeywordRole);
        var inner = groupJoin.InnerSelector.Statements.FirstOrDefault() as ContextualReturn;
        if (inner != null)
          result.AddChild((Expression)inner.Expr.Accept(this), QueryJoinClause.EqualsExpressionRole);
        
        if (location != null && location.Count > 3)
          result.AddChild(new CSharpTokenNode(Convert(location [3]), QueryJoinClause.IntoKeywordRole), QueryJoinClause.IntoKeywordRole);
        
        result.AddChild(Identifier.Create(groupJoin.JoinVariable.Name, Convert(groupJoin.JoinVariable.Location)), QueryJoinClause.IntoIdentifierRole);
        return result;
      }

      public override object Visit(Mono.CSharp.Linq.OrderByAscending orderByAscending)
      {
        currentQueryOrderClause = new QueryOrderClause();
        var location2 = LocationsBag.GetLocations(orderByAscending.block);
        if (location2 != null)
          currentQueryOrderClause.AddChild(new CSharpTokenNode(Convert(location2 [0]), QueryOrderClause.OrderbyKeywordRole), QueryOrderClause.OrderbyKeywordRole);
        var ordering = new QueryOrdering();
        if (orderByAscending.Expr != null)
          ordering.AddChild((Expression)orderByAscending.Expr.Accept(this), Roles.Expression);
        var location = LocationsBag.GetLocations(orderByAscending);
        if (location != null) {
          ordering.Direction = QueryOrderingDirection.Ascending;
          ordering.AddChild(new CSharpTokenNode(Convert(location [0]), QueryOrdering.AscendingKeywordRole), QueryOrdering.AscendingKeywordRole);
        }
        currentQueryOrderClause.AddChild(ordering, QueryOrderClause.OrderingRole);
        return currentQueryOrderClause;
      }

      public override object Visit(Mono.CSharp.Linq.OrderByDescending orderByDescending)
      {
        currentQueryOrderClause = new QueryOrderClause();
        
        var ordering = new QueryOrdering();
        if (orderByDescending.Expr != null)
          ordering.AddChild((Expression)orderByDescending.Expr.Accept(this), Roles.Expression);
        var location = LocationsBag.GetLocations(orderByDescending);
        if (location != null) {
          ordering.Direction = QueryOrderingDirection.Descending;
          ordering.AddChild(new CSharpTokenNode(Convert(location [0]), QueryOrdering.DescendingKeywordRole), QueryOrdering.DescendingKeywordRole);
        }
        currentQueryOrderClause.AddChild(ordering, QueryOrderClause.OrderingRole);
        return currentQueryOrderClause;
      }

      public override object Visit(Mono.CSharp.Linq.ThenByAscending thenByAscending)
      {
        var ordering = new QueryOrdering();
        if (thenByAscending.Expr != null)
          ordering.AddChild((Expression)thenByAscending.Expr.Accept(this), Roles.Expression);
        var location = LocationsBag.GetLocations(thenByAscending);
        if (location != null) {
          ordering.Direction = QueryOrderingDirection.Ascending;
          ordering.AddChild(new CSharpTokenNode(Convert(location [0]), QueryOrdering.AscendingKeywordRole), QueryOrdering.AscendingKeywordRole);
        }
        currentQueryOrderClause.AddChild(ordering, QueryOrderClause.OrderingRole);
        return null;
      }

      public override object Visit(Mono.CSharp.Linq.ThenByDescending thenByDescending)
      {
        var ordering = new QueryOrdering();
        if (thenByDescending.Expr != null)
          ordering.AddChild((Expression)thenByDescending.Expr.Accept(this), Roles.Expression);
        var location = LocationsBag.GetLocations(thenByDescending);
        if (location != null) {
          ordering.Direction = QueryOrderingDirection.Descending;
          ordering.AddChild(new CSharpTokenNode(Convert(location [0]), QueryOrdering.DescendingKeywordRole), QueryOrdering.DescendingKeywordRole);
        }
        currentQueryOrderClause.AddChild(ordering, QueryOrderClause.OrderingRole);
        return null;
      }

      public override object Visit(Await awaitExpr)
      {
        var result = new UnaryOperatorExpression();
        result.Operator = UnaryOperatorType.Await;
        result.AddChild(new CSharpTokenNode(Convert(awaitExpr.Location), UnaryOperatorExpression.AwaitRole), UnaryOperatorExpression.AwaitRole);
        if (awaitExpr.Expression != null)
          result.AddChild((Expression)awaitExpr.Expression.Accept(this), Roles.Expression);
        return result;
      }

      #endregion

      #region XmlDoc

      public DocumentationReference ConvertXmlDoc(DocumentationBuilder doc)
      {
        var result = new DocumentationReference();
        if (doc.ParsedName != null) {
          if (doc.ParsedName.Name == "<this>") {
            result.SymbolKind = SymbolKind.Indexer;
          } else {
            result.MemberName = doc.ParsedName.Name;
          }
          if (doc.ParsedName.Left != null) {
            result.DeclaringType = ConvertToType(doc.ParsedName.Left);
          } else if (doc.ParsedBuiltinType != null) {
            result.DeclaringType = ConvertToType(doc.ParsedBuiltinType);
          }
          if (doc.ParsedName.TypeParameters != null) {
            for (int i = 0; i < doc.ParsedName.TypeParameters.Count; i++) {
              result.TypeArguments.Add(ConvertToType(doc.ParsedName.TypeParameters [i]));
            }
          }
        } else if (doc.ParsedBuiltinType != null) {
          result.SymbolKind = SymbolKind.TypeDefinition;
          result.DeclaringType = ConvertToType(doc.ParsedBuiltinType);
        }
        if (doc.ParsedParameters != null) {
          result.HasParameterList = true;
          result.Parameters.AddRange(doc.ParsedParameters.Select(ConvertXmlDocParameter));
        }
        if (doc.ParsedOperator != null) {
          result.SymbolKind = SymbolKind.Operator;
          result.OperatorType = (OperatorType)doc.ParsedOperator;
          if (result.OperatorType == OperatorType.Implicit || result.OperatorType == OperatorType.Explicit) {
            var returnTypeParam = result.Parameters.LastOrNullObject();
            returnTypeParam.Remove(); // detach from parameter list
            var returnType = returnTypeParam.Type;
            returnType.Remove();
            result.ConversionOperatorReturnType = returnType;
          }
          if (result.Parameters.Count == 0) {
            // reset HasParameterList if necessary
            result.HasParameterList = false;
          }
        }
        return result;
      }

      ParameterDeclaration ConvertXmlDocParameter(DocumentationParameter p)
      {
        var result = new ParameterDeclaration();
        switch (p.Modifier) {
          case Parameter.Modifier.OUT:
            result.ParameterModifier = ParameterModifier.Out;
            break;
          case Parameter.Modifier.REF:
            result.ParameterModifier = ParameterModifier.Ref;
            break;
          case Parameter.Modifier.PARAMS:
            result.ParameterModifier = ParameterModifier.Params;
            break;
        }
        if (p.Type != null) {
          result.Type = ConvertToType(p.Type);
        }
        return result;
      }

      #endregion

    }

    public CSharpParser()
    {
      compilerSettings = new CompilerSettings();
    }

    public CSharpParser(CompilerSettings args)
    {
      compilerSettings = args ?? new CompilerSettings();
    }

    void InsertComments(CompilerCompilationUnit top, ConversionVisitor conversionVisitor)
    {
      AstNode insertionPoint = conversionVisitor.Unit.FirstChild;
      foreach (var special in top.SpecialsBag.Specials) {
        AstNode newLeaf = null;
        Role role = null;
        bool isDocumentationComment = false;
        var comment = special as SpecialsBag.Comment;
        if (comment != null) {
          // HACK: multiline documentation comment detection; better move this logic into the mcs tokenizer
          bool isMultilineDocumentationComment = (comment.CommentType == SpecialsBag.CommentType.Multi && comment.Content.StartsWith("*", StringComparison.Ordinal) && !comment.Content.StartsWith("**", StringComparison.Ordinal));
          isDocumentationComment = comment.CommentType == SpecialsBag.CommentType.Documentation || isMultilineDocumentationComment;
          if (conversionVisitor.convertTypeSystemMode && !isDocumentationComment)
            continue;
          var type = isMultilineDocumentationComment ? CommentType.MultiLineDocumentation : (CommentType)comment.CommentType;
          var start = new TextLocation(comment.Line, comment.Col);
          var end = new TextLocation(comment.EndLine, comment.EndCol);
          newLeaf = new Comment(type, start, end) {
            StartsLine = comment.StartsLine,
            Content = isMultilineDocumentationComment ? comment.Content.Substring(1) : comment.Content
          };
          role = Roles.Comment;
        } else if (!GenerateTypeSystemMode) {
          var pragmaDirective = special as SpecialsBag.PragmaPreProcessorDirective;
          if (pragmaDirective != null) {
            var pragma = new PragmaWarningPreprocessorDirective(new TextLocation(pragmaDirective.Line, pragmaDirective.Col), new TextLocation(pragmaDirective.EndLine, pragmaDirective.EndCol));
            pragma.AddChild(new CSharpTokenNode(new TextLocation(pragmaDirective.Line, pragmaDirective.Col), PragmaWarningPreprocessorDirective.PragmaKeywordRole), PragmaWarningPreprocessorDirective.PragmaKeywordRole);
            pragma.AddChild(new CSharpTokenNode(new TextLocation(pragmaDirective.Line, pragmaDirective.WarningColumn), PragmaWarningPreprocessorDirective.WarningKeywordRole), PragmaWarningPreprocessorDirective.WarningKeywordRole);
            var pragmaRole = pragmaDirective.Disalbe ? PragmaWarningPreprocessorDirective.DisableKeywordRole : PragmaWarningPreprocessorDirective.RestoreKeywordRole;
            pragma.AddChild(new CSharpTokenNode(new TextLocation(pragmaDirective.Line, pragmaDirective.DisableRestoreColumn), pragmaRole), pragmaRole);
            foreach (var code in pragmaDirective.Codes) {
              pragma.AddChild((PrimitiveExpression)conversionVisitor.Visit(code), PragmaWarningPreprocessorDirective.WarningRole);
            }
            newLeaf = pragma;
            role = Roles.PreProcessorDirective;
            goto end;
          }
          var lineDirective = special as SpecialsBag.LineProcessorDirective;
          if (lineDirective != null) {
            var pragma = new LinePreprocessorDirective(new TextLocation(lineDirective.Line, lineDirective.Col), new TextLocation(lineDirective.EndLine, lineDirective.EndCol));
            pragma.LineNumber = lineDirective.LineNumber;
            pragma.FileName = lineDirective.FileName;
            newLeaf = pragma;
            role = Roles.PreProcessorDirective;
            goto end;
          }
          var directive = special as SpecialsBag.PreProcessorDirective;
          if (directive != null) {
            newLeaf = new PreProcessorDirective((PreProcessorDirectiveType)((int)directive.Cmd & 0xF), new TextLocation(directive.Line, directive.Col), new TextLocation(directive.EndLine, directive.EndCol)) {
              Argument = directive.Arg,
              Take = directive.Take
            };
            role = Roles.PreProcessorDirective;
          }
          end:
          ;
        }
        if (newLeaf != null) {
          InsertComment(ref insertionPoint, newLeaf, role, isDocumentationComment, conversionVisitor.Unit);
        }
      }
      if (!GenerateTypeSystemMode) {
        // We cannot insert newlines in the same loop as comments/preprocessor directives
        // because they are not correctly ordered in the specials bag
        insertionPoint = conversionVisitor.Unit.FirstChild;
        for (int i = 0; i < top.SpecialsBag.Specials.Count; i++) {
          var newLine = top.SpecialsBag.Specials [i] as SpecialsBag.NewLineToken;
          if (newLine != null) {
            var newLeaf = new NewLineNode(new TextLocation(newLine.Line, newLine.Col + 1));
            newLeaf.NewLineType = newLine.NewLine == SpecialsBag.NewLine.Unix ? UnicodeNewline.LF : UnicodeNewline.CRLF;
            InsertComment(ref insertionPoint, newLeaf, Roles.NewLine, false, conversionVisitor.Unit);
          }
        }
      }
    }

    static void InsertComment(ref AstNode insertionPoint, AstNode newNode, Role role, bool isDocumentationComment, AstNode rootNode)
    {
      TextLocation insertAt = newNode.StartLocation;
      // Advance insertionPoint to the first node that has a start location >= insertAt
      while (insertionPoint != null && insertionPoint.StartLocation < insertAt) {
        // Enter the current node if insertAt is within
        while (insertAt < insertionPoint.EndLocation && insertionPoint.FirstChild != null) {
          insertionPoint = insertionPoint.FirstChild;
        }
        // Go to next node (insertionPoint.NextSibling if it exists; otherwise the next sibling of the parent node etc.)
        insertionPoint = insertionPoint.GetNextNode();
      }
      // As a special case, XmlDoc gets inserted at the beginning of the entity declaration
      if (isDocumentationComment && insertionPoint is EntityDeclaration && insertionPoint.FirstChild != null) {
        insertionPoint = insertionPoint.FirstChild;
      }
      if (insertionPoint == null) {
        // we're at the end of the compilation unit
        rootNode.AddChildUnsafe(newNode, role);
      } else {
        insertionPoint.Parent.InsertChildBeforeUnsafe(insertionPoint, newNode, role);
      }
    }

    public class ErrorReportPrinter : ReportPrinter
    {
      readonly string fileName;
      public readonly List<Error> Errors = new List<Error>();

      public ErrorReportPrinter(string fileName)
      {
        this.fileName = fileName;
      }

      public override void Print(AbstractMessage msg, bool showFullPath)
      {
        base.Print(msg, showFullPath);
        var newError = new Error(msg.IsWarning ? ErrorType.Warning : ErrorType.Error, msg.Text, new DomRegion(fileName, msg.Location.Row, msg.Location.Column));
        Errors.Add(newError);
      }
    }

    ErrorReportPrinter errorReportPrinter = new ErrorReportPrinter(null);

    [Obsolete("Use the Errors/Warnings/ErrorsAndWarnings properties instead")]
    public ErrorReportPrinter ErrorPrinter {
      get {
        return errorReportPrinter;
      }
    }

    public bool HasErrors {
      get {
        return errorReportPrinter.ErrorsCount > 0;
      }
    }

    public bool HasWarnings {
      get {
        return errorReportPrinter.WarningsCount > 0;
      }
    }

    public IEnumerable<Error> Errors {
      get {
        return errorReportPrinter.Errors.Where(e => e.ErrorType == ErrorType.Error);
      }
    }

    public IEnumerable<Error> Warnings {
      get {
        return errorReportPrinter.Errors.Where(e => e.ErrorType == ErrorType.Warning);
      }
    }

    public IEnumerable<Error> ErrorsAndWarnings {
      get { return errorReportPrinter.Errors; }
    }

    /// <summary>
    /// Parses a C# code file.
    /// </summary>
    /// <param name="program">The source code to parse.</param>
    /// <param name="fileName">The file name. Used to identify the file (e.g. when building a type system).
    /// This can be an arbitrary identifier, NRefactory never tries to access the file on disk.</param>
    /// <returns>Returns the syntax tree.</returns>
    public SyntaxTree Parse(string program, string fileName = "")
    {
      return Parse(new StringTextSource(program), fileName);
    }

    /// <summary>
    /// Parses a C# code file.
    /// </summary>
    /// <param name="reader">The text reader containing the source code to parse.</param>
    /// <param name="fileName">The file name. Used to identify the file (e.g. when building a type system).
    /// This can be an arbitrary identifier, NRefactory never tries to access the file on disk.</param>
    /// <returns>Returns the syntax tree.</returns>
    public SyntaxTree Parse(TextReader reader, string fileName = "")
    {
      return Parse(new StringTextSource(reader.ReadToEnd()), fileName);
    }

    /// <summary>
    /// Converts a Mono.CSharp syntax tree into an NRefactory syntax tree.
    /// </summary>
    public SyntaxTree Parse(CompilerCompilationUnit top, string fileName)
    {
      if (top == null) {
        return null;
      }
      CSharpParser.ConversionVisitor conversionVisitor = new ConversionVisitor(GenerateTypeSystemMode, top.LocationsBag);
      top.ModuleCompiled.Accept(conversionVisitor);
      InsertComments(top, conversionVisitor);
      if (CompilationUnitCallback != null) {
        CompilationUnitCallback(top);
      }
      var expr = top.LastYYValue as Mono.CSharp.Expression;
      if (expr != null)
        conversionVisitor.Unit.TopExpression = expr.Accept(conversionVisitor) as AstNode;

      conversionVisitor.Unit.FileName = fileName;
      var conditionals = new List<string>();
      foreach (var settings in compilerSettings.ConditionalSymbols) {
        if (top.Conditionals.ContainsKey(settings) && !top.Conditionals [settings])
          continue;
        conditionals.Add(settings);
      }
      foreach (var kv in top.Conditionals) {
        if (!kv.Value || compilerSettings.ConditionalSymbols.Contains(kv.Key))
          continue;
        conditionals.Add(kv.Key);
      }
      conversionVisitor.Unit.ConditionalSymbols = conditionals;
      return conversionVisitor.Unit;
    }

    public CompilerSettings CompilerSettings {
      get { return compilerSettings; }
      set {
        if (value == null)
          throw new ArgumentNullException();
        compilerSettings = value;
      }
    }

    /// <summary>
    /// Callback that gets called with the Mono.CSharp syntax tree whenever some code is parsed.
    /// </summary>
    public Action<CompilerCompilationUnit> CompilationUnitCallback {
      get;
      set;
    }

    /// <summary>
    /// Specifies whether to run the parser in a special mode for generating the type system.
    /// If this property is true, the syntax tree will only contain nodes relevant for the
    /// <see cref="SyntaxTree.ToTypeSystem()"/> call and might be missing other nodes (e.g. method bodies).
    /// The default is false.
    /// </summary>
    public bool GenerateTypeSystemMode {
      get;
      set;
    }

    TextLocation initialLocation = new TextLocation(1, 1);

    /// <summary>
    /// Specifies the text location where parsing starts.
    /// This property can be used when parsing a part of a file to make the locations of the AstNodes
    /// refer to the position in the whole file.
    /// The default is (1,1).
    /// </summary>
    public TextLocation InitialLocation {
      get { return initialLocation; }
      set { initialLocation = value; }
    }

    internal static object parseLock = new object();

    /// <summary>
    /// Parses a C# code file.
    /// </summary>
    /// <param name="stream">The stream containing the source code to parse.</param>
    /// <param name="fileName">The file name. Used to identify the file (e.g. when building a type system).
    /// This can be an arbitrary identifier, NRefactory never tries to access the file on disk.</param>
    /// <returns>Returns the syntax tree.</returns>
    public SyntaxTree Parse(Stream stream, string fileName = "")
    {
      return Parse(new StreamReader(stream), fileName);
    }

    /// <summary>
    /// Parses a C# code file.
    /// </summary>
    /// <param name="program">The source code to parse.</param>
    /// <param name="fileName">The file name. Used to identify the file (e.g. when building a type system).
    /// This can be an arbitrary identifier, NRefactory never tries to access the file on disk.</param>
    /// <returns>Returns the syntax tree.</returns>
    public SyntaxTree Parse(ITextSource program, string fileName = "")
    {
      return Parse(program, fileName, initialLocation.Line, initialLocation.Column);
    }

    SyntaxTree Parse(ITextSource program, string fileName, int initialLine, int initialColumn)
    {
      lock (parseLock) {
        errorReportPrinter = new ErrorReportPrinter("");
        var ctx = new CompilerContext(compilerSettings.ToMono(), errorReportPrinter);
        ctx.Settings.TabSize = 1;
        var reader = new SeekableStreamReader(program);
        var file = new SourceFile(fileName, fileName, 0);
        Location.Initialize(new List<SourceFile>(new [] { file }));
        var module = new ModuleContainer(ctx);
        var session = new ParserSession();
        session.LocationsBag = new LocationsBag();
        var report = new Report(ctx, errorReportPrinter);
        var parser = Driver.Parse(reader, file, module, session, report, initialLine - 1, initialColumn - 1);
        var top = new CompilerCompilationUnit {
          ModuleCompiled = module,
          LocationsBag = session.LocationsBag,
          SpecialsBag = parser.Lexer.sbag,
          Conditionals = parser.Lexer.SourceFile.Conditionals
        };
        var unit = Parse(top, fileName);
        unit.Errors.AddRange(errorReportPrinter.Errors);
        CompilerCallableEntryPoint.Reset();
        return unit;
      }
    }

    public IEnumerable<EntityDeclaration> ParseTypeMembers(string code)
    {
      return ParseTypeMembers(code, initialLocation.Line, initialLocation.Column);
    }

    IEnumerable<EntityDeclaration> ParseTypeMembers(string code, int initialLine, int initialColumn)
    {
      const string prefix = "unsafe partial class MyClass { ";
      var syntaxTree = Parse(new StringTextSource(prefix + code + "}"), "parsed.cs", initialLine, initialColumn - prefix.Length);
      if (syntaxTree == null)
        return Enumerable.Empty<EntityDeclaration>();
      var td = syntaxTree.FirstChild as TypeDeclaration;
      if (td != null) {
        var members = td.Members.ToArray();
        // detach members from parent
        foreach (var m in members)
          m.Remove();
        return members;
      }
      return Enumerable.Empty<EntityDeclaration>();
    }

    public IEnumerable<Statement> ParseStatements(string code)
    {
      return ParseStatements(code, initialLocation.Line, initialLocation.Column);
    }

    IEnumerable<Statement> ParseStatements(string code, int initialLine, int initialColumn)
    {
      // the dummy method is async so that 'await' expressions are parsed as expected
      const string prefix = "async void M() { ";
      var members = ParseTypeMembers(prefix + code + "}", initialLine, initialColumn - prefix.Length);
      var method = members.FirstOrDefault() as MethodDeclaration;
      if (method != null && method.Body != null) {
        var statements = method.Body.Statements.ToArray();
        // detach statements from parent
        foreach (var st in statements)
          st.Remove();
        return statements;
      }
      return Enumerable.Empty<Statement>();
    }

    public AstType ParseTypeReference(string code)
    {
      var members = ParseTypeMembers(code + " a;");
      var field = members.FirstOrDefault() as FieldDeclaration;
      if (field != null) {
        AstType type = field.ReturnType;
        type.Remove();
        return type;
      }
      return AstType.Null;
    }

    public Expression ParseExpression(string code)
    {
      const string prefix = "tmp = ";
      var statements = ParseStatements(prefix + code + ";", initialLocation.Line, initialLocation.Column - prefix.Length);
      var es = statements.FirstOrDefault() as ExpressionStatement;
      if (es != null) {
        var ae = es.Expression as AssignmentExpression;
        if (ae != null) {
          Expression expr = ae.Right;
          expr.Remove();
          return expr;
        }
      }
      return Expression.Null;
    }
    /*
    /// <summary>
    /// Parses a file snippet; guessing what the code snippet represents (whole file, type members, block, type reference, expression).
    /// </summary>
    public AstNode ParseSnippet (string code)
    {
      // TODO: add support for parsing a part of a file
      throw new NotImplementedException ();
    }
     */
    public DocumentationReference ParseDocumentationReference(string cref)
    {
      // see Mono.CSharp.DocumentationBuilder.HandleXrefCommon
      if (cref == null)
        throw new ArgumentNullException("cref");
      
      // Additional symbols for < and > are allowed for easier XML typing
      cref = cref.Replace('{', '<').Replace('}', '>');
      
      lock (parseLock) {
        errorReportPrinter = new ErrorReportPrinter("");
        var ctx = new CompilerContext(compilerSettings.ToMono(), errorReportPrinter);
        ctx.Settings.TabSize = 1;
        var reader = new SeekableStreamReader(new StringTextSource(cref));
        var file = new SourceFile("", "", 0);
        Location.Initialize(new List<SourceFile>(new [] { file }));
        var module = new ModuleContainer(ctx);
        module.DocumentationBuilder = new DocumentationBuilder(module);
        var source_file = new CompilationSourceFile(module);
        var report = new Report(ctx, errorReportPrinter);
        var session = new ParserSession();
        session.LocationsBag = new LocationsBag();
        var parser = new Mono.CSharp.CSharpParser(reader, source_file, report, session);
        parser.Lexer.Line += initialLocation.Line - 1;
        parser.Lexer.Column += initialLocation.Column - 1;
        parser.Lexer.putback_char = Tokenizer.DocumentationXref;
        parser.Lexer.parsing_generic_declaration_doc = true;
        parser.parse();
        if (report.Errors > 0) {
//          Report.Warning (1584, 1, mc.Location, "XML comment on `{0}' has syntactically incorrect cref attribute `{1}'",
//                          mc.GetSignatureForError (), cref);
        }
        
        var conversionVisitor = new ConversionVisitor(false, session.LocationsBag);
        var docRef = conversionVisitor.ConvertXmlDoc(module.DocumentationBuilder);
        CompilerCallableEntryPoint.Reset();
        return docRef;
      }
    }
  }
}