source: tags/3.3.13/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Ast/AstNodeCollection.cs @ 18242

// Copyright (c) 2010-2013 AlphaSierraPapa for the SharpDevelop Team
// 
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// 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
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using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using ICSharpCode.NRefactory.PatternMatching;

namespace ICSharpCode.NRefactory.CSharp
{
  /// <summary>
  /// Represents the children of an AstNode that have a specific role.
  /// </summary>
  public class AstNodeCollection<T> : ICollection<T>
    #if NET_4_5
    , IReadOnlyCollection<T>
    #endif
    where T : AstNode
  {
    readonly AstNode node;
    readonly Role<T> role;
    
    public AstNodeCollection(AstNode node, Role<T> role)
    {
      if (node == null)
        throw new ArgumentNullException("node");
      if (role == null)
        throw new ArgumentNullException("role");
      this.node = node;
      this.role = role;
    }
    
    public int Count {
      get {
        int count = 0;
        uint roleIndex = role.Index;
        for (AstNode cur = node.FirstChild; cur != null; cur = cur.NextSibling) {
          if (cur.RoleIndex == roleIndex)
            count++;
        }
        return count;
      }
    }
    
    public void Add(T element)
    {
      node.AddChild(element, role);
    }
    
    public void AddRange(IEnumerable<T> nodes)
    {
      // Evaluate 'nodes' first, since it might change when we add the new children
      // Example: collection.AddRange(collection);
      if (nodes != null) {
        foreach (T node in nodes.ToList())
          Add(node);
      }
    }
    
    public void AddRange(T[] nodes)
    {
      // Fast overload for arrays - we don't need to create a copy
      if (nodes != null) {
        foreach (T node in nodes)
          Add(node);
      }
    }
    
    public void ReplaceWith(IEnumerable<T> nodes)
    {
      // Evaluate 'nodes' first, since it might change when we call Clear()
      // Example: collection.ReplaceWith(collection);
      if (nodes != null)
        nodes = nodes.ToList();
      Clear();
      if (nodes != null) {
        foreach (T node in nodes)
          Add(node);
      }
    }
    
    public void MoveTo(ICollection<T> targetCollection)
    {
      if (targetCollection == null)
        throw new ArgumentNullException("targetCollection");
      foreach (T node in this) {
        node.Remove();
        targetCollection.Add(node);
      }
    }
    
    public bool Contains(T element)
    {
      return element != null && element.Parent == node && element.RoleIndex == role.Index;
    }
    
    public bool Remove(T element)
    {
      if (Contains(element)) {
        element.Remove();
        return true;
      } else {
        return false;
      }
    }
    
    public void CopyTo(T[] array, int arrayIndex)
    {
      foreach (T item in this)
        array[arrayIndex++] = item;
    }
    
    public void Clear()
    {
      foreach (T item in this)
        item.Remove();
    }
    
    /// <summary>
    /// Returns the first element for which the predicate returns true,
    /// or the null node (AstNode with IsNull=true) if no such object is found.
    /// </summary>
    public T FirstOrNullObject(Func<T, bool> predicate = null)
    {
      foreach (T item in this)
        if (predicate == null || predicate(item))
          return item;
      return role.NullObject;
    }
    
    /// <summary>
    /// Returns the last element for which the predicate returns true,
    /// or the null node (AstNode with IsNull=true) if no such object is found.
    /// </summary>
    public T LastOrNullObject(Func<T, bool> predicate = null)
    {
      T result = role.NullObject;
      foreach (T item in this)
        if (predicate == null || predicate(item))
          result = item;
      return result;
    }
    
    bool ICollection<T>.IsReadOnly {
      get { return false; }
    }
    
    public IEnumerator<T> GetEnumerator()
    {
      uint roleIndex = role.Index;
      AstNode next;
      for (AstNode cur = node.FirstChild; cur != null; cur = next) {
        Debug.Assert(cur.Parent == node);
        // Remember next before yielding cur.
        // This allows removing/replacing nodes while iterating through the list.
        next = cur.NextSibling;
        if (cur.RoleIndex == roleIndex)
          yield return (T)cur;
      }
    }
    
    IEnumerator IEnumerable.GetEnumerator()
    {
      return GetEnumerator();
    }
    
    #region Equals and GetHashCode implementation
    public override int GetHashCode()
    {
      return node.GetHashCode() ^ role.GetHashCode();
    }
    
    public override bool Equals(object obj)
    {
      AstNodeCollection<T> other = obj as AstNodeCollection<T>;
      if (other == null)
        return false;
      return this.node == other.node && this.role == other.role;
    }
    #endregion
    
    internal bool DoMatch(AstNodeCollection<T> other, Match match)
    {
      return Pattern.DoMatchCollection(role, node.FirstChild, other.node.FirstChild, match);
    }
    
    public void InsertAfter(T existingItem, T newItem)
    {
      node.InsertChildAfter(existingItem, newItem, role);
    }
    
    public void InsertBefore(T existingItem, T newItem)
    {
      node.InsertChildBefore(existingItem, newItem, role);
    }
    
    /// <summary>
    /// Applies the <paramref name="visitor"/> to all nodes in this collection.
    /// </summary>
    public void AcceptVisitor(IAstVisitor visitor)
    {
      uint roleIndex = role.Index;
      AstNode next;
      for (AstNode cur = node.FirstChild; cur != null; cur = next) {
        Debug.Assert(cur.Parent == node);
        // Remember next before yielding cur.
        // This allows removing/replacing nodes while iterating through the list.
        next = cur.NextSibling;
        if (cur.RoleIndex == roleIndex)
          cur.AcceptVisitor(visitor);
      }
    }
  }
}