source: branches/CodeEditor/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory-5.5.0/TypeSystem/SpecialType.cs @ 11700

// Copyright (c) 2010-2013 AlphaSierraPapa for the SharpDevelop Team
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

using System;
using System.Collections.Generic;
using ICSharpCode.NRefactory.TypeSystem.Implementation;

namespace ICSharpCode.NRefactory.TypeSystem
{
  /// <summary>
  /// Contains static implementations of special types.
  /// </summary>
  [Serializable]
  public sealed class SpecialType : AbstractType, ITypeReference
  {
    /// <summary>
    /// Gets the type representing resolve errors.
    /// </summary>
    public readonly static SpecialType UnknownType = new SpecialType(TypeKind.Unknown, "?", isReferenceType: null);
    
    /// <summary>
    /// The null type is used as type of the null literal. It is a reference type without any members; and it is a subtype of all reference types.
    /// </summary>
    public readonly static SpecialType NullType = new SpecialType(TypeKind.Null, "null", isReferenceType: true);
    
    /// <summary>
    /// Type representing the C# 'dynamic' type.
    /// </summary>
    public readonly static SpecialType Dynamic = new SpecialType(TypeKind.Dynamic, "dynamic", isReferenceType: true);
    
    /// <summary>
    /// A type used for unbound type arguments in partially parameterized types.
    /// </summary>
    /// <see cref="IType.GetNestedTypes(Predicate{ITypeDefinition}, GetMemberOptions)"/>
    public readonly static SpecialType UnboundTypeArgument = new SpecialType(TypeKind.UnboundTypeArgument, "", isReferenceType: null);
    
    readonly TypeKind kind;
    readonly string name;
    readonly bool? isReferenceType;
    
    private SpecialType(TypeKind kind, string name, bool? isReferenceType)
    {
      this.kind = kind;
      this.name = name;
      this.isReferenceType = isReferenceType;
    }
    
    public override ITypeReference ToTypeReference()
    {
      return this;
    }
    
    public override string Name {
      get { return name; }
    }
    
    public override TypeKind Kind {
      get { return kind; }
    }
    
    public override bool? IsReferenceType {
      get { return isReferenceType; }
    }
    
    IType ITypeReference.Resolve(ITypeResolveContext context)
    {
      if (context == null)
        throw new ArgumentNullException("context");
      return this;
    }
    
    #pragma warning disable 809
    [Obsolete("Please compare special types using the kind property instead.")]
    public override bool Equals(IType other)
    {
      // We consider a special types equal when they have equal types.
      // However, an unknown type with additional information is not considered to be equal to the SpecialType with TypeKind.Unknown.
      return other is SpecialType && other.Kind == kind;
    }
    
    public override int GetHashCode()
    {
      return 81625621 ^ (int)kind;
    }
  }
}