source: trunk/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Analysis/DeclarationSpace/LocalDeclarationSpace.cs

// 
// LovalVariableDeclarationSpace.cs
//  
// Author:
//       Simon Lindgren <simon.n.lindgren@gmail.com>
// 
// Copyright (c) 2013 Simon Lindgren
// 
// 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 ICSharpCode.NRefactory.Utils;
using System.Collections.Generic;
using System.Linq;
using System;

namespace ICSharpCode.NRefactory.CSharp.Analysis
{
  /// <summary>
  /// Represents a declaration space. (§3.3)
  /// </summary>
  public class LocalDeclarationSpace
  {
    /// <summary>
    /// Maps from variable name to the declarations in this declaration space.
    /// </summary>
    /// <remarks>
    /// This maps from variable name
    /// </remarks>
    MultiDictionary<string, AstNode> declarations = new MultiDictionary<string, AstNode> ();

    public LocalDeclarationSpace()
    {
      Children = new List<LocalDeclarationSpace> ();
    }

    /// <summary>
    /// The child declaration spaces.
    /// </summary>
    public IList<LocalDeclarationSpace> Children {
      get;
      private set;
    }

    /// <summary>
    /// The parent declaration space.
    /// </summary>
    /// <value>The parent.</value>
    public LocalDeclarationSpace Parent {
      get;
      private set;
    }

    /// <summary>
    /// The names declared in this declaration space, excluding child spaces.
    /// </summary>
    /// <value>The declared names.</value>
    public ICollection<string> DeclaredNames {
      get {
        return declarations.Keys;
      }
    }

    /// <summary>
    /// Get all nodes declaring the name specified in <paramref name="name"/>.
    /// </summary>
    /// <returns>The declaring nodes.</returns>
    /// <param name="name">The declaration name.</param>
    public IEnumerable<AstNode> GetNameDeclarations(string name)
    {
      return declarations [name].Concat(Children.SelectMany(child => child.GetNameDeclarations(name)));
    }

    /// <summary>
    /// Adds a child declaration space.
    /// </summary>
    /// <param name="child">The <see cref="LocalDeclarationSpace"/> to add.</param>
    public void AddChildSpace(LocalDeclarationSpace child)
    {
      if (child == null)
        throw new ArgumentNullException("child");
      if (Children.Contains(child))
        throw new InvalidOperationException("the child was already added");

      Children.Add(child);
      child.Parent = this;
    }

    /// <summary>
    /// Adds a new declaration to the declaration space.
    /// </summary>
    /// <param name="name">The name of the declared variable.</param>
    /// <param name="node">A node associated with the declaration.</param>
    public void AddDeclaration(string name, AstNode node)
    {
      if (name == null)
        throw new ArgumentNullException("name");
      if (node == null)
        throw new ArgumentNullException("node");
      declarations.Add(name, node);
    }

    /// <summary>
    /// Determines if the name exists in the this declaration space.
    /// </summary>
    /// <returns><c>true</c>, if the name specified in <paramref name="name"/> is used in this variable declaration space, <c>false</c> otherwise.</returns>
    /// <param name="name">The name to look for.</param>
    /// <param name="includeChildren">When <c>true</c>, child declaration spaces are included in the search.</param>
    public bool ContainsName(string name, bool includeChildren)
    {
      if (name == null)
        throw new ArgumentNullException("name");

      if (declarations.Keys.Contains(name)) 
        return true;
      return includeChildren && Children.Any(child => child.ContainsName(name, true));
    }

    /// <summary>
    /// Determines whether the name specified in <paramref name="name"/> is used in surrouding code.
    /// </summary>
    /// <returns><c>true</c> if the name is used, <c>false</c> otherwise.</returns>
    /// <param name="name">The name to check.</param>
    /// <remarks>
    /// Contrary to <see cref="ContainsName"/>, this method also checks parent declaration spaces
    /// for name conflicts. Typically, this will be the right method to use when determining if a name can be used.
    /// </remarks>
    public bool IsNameUsed(string name)
    {
      if (name == null)
        throw new ArgumentNullException("name");

      return IsNameUsedBySelfOrParent(name) || Children.Any(child => child.ContainsName(name, true));
    }

    bool IsNameUsedBySelfOrParent(string name)
    {
      if (declarations.Keys.Contains(name))
        return true;
      return Parent != null && Parent.IsNameUsedBySelfOrParent(name);
    }
  }
}