source: branches/PersistenceOverhaul/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory-5.5.0/Utils/ProjectedList.cs

// 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;

namespace ICSharpCode.NRefactory.Utils
{
  public sealed class ProjectedList<TInput, TOutput> : IList<TOutput> where TOutput : class
  {
    readonly IList<TInput> input;
    readonly Func<TInput, TOutput> projection;
    readonly TOutput[] items;
    
    public ProjectedList(IList<TInput> input, Func<TInput, TOutput> projection)
    {
      if (input == null)
        throw new ArgumentNullException("input");
      if (projection == null)
        throw new ArgumentNullException("projection");
      this.input = input;
      this.projection = projection;
      this.items = new TOutput[input.Count];
    }
    
    public TOutput this[int index] {
      get {
        TOutput output = LazyInit.VolatileRead(ref items[index]);
        if (output != null) {
          return output;
        }
        return LazyInit.GetOrSet(ref items[index], projection(input[index]));
      }
    }
    
    TOutput IList<TOutput>.this[int index] {
      get { return this[index]; }
      set {
        throw new NotSupportedException();
      }
    }
    
    public int Count {
      get { return items.Length; }
    }
    
    bool ICollection<TOutput>.IsReadOnly {
      get { return true; }
    }
    
    int IList<TOutput>.IndexOf(TOutput item)
    {
      var comparer = EqualityComparer<TOutput>.Default;
      for (int i = 0; i < this.Count; i++) {
        if (comparer.Equals(this[i], item))
          return i;
      }
      return -1;
    }
    
    void IList<TOutput>.Insert(int index, TOutput item)
    {
      throw new NotSupportedException();
    }
    
    void IList<TOutput>.RemoveAt(int index)
    {
      throw new NotSupportedException();
    }
    
    void ICollection<TOutput>.Add(TOutput item)
    {
      throw new NotSupportedException();
    }
    
    void ICollection<TOutput>.Clear()
    {
      throw new NotSupportedException();
    }
    
    bool ICollection<TOutput>.Contains(TOutput item)
    {
      var comparer = EqualityComparer<TOutput>.Default;
      for (int i = 0; i < this.Count; i++) {
        if (comparer.Equals(this[i], item))
          return true;
      }
      return false;
    }
    
    void ICollection<TOutput>.CopyTo(TOutput[] array, int arrayIndex)
    {
      for (int i = 0; i < items.Length; i++) {
        array[arrayIndex + i] = this[i];
      }
    }
    
    bool ICollection<TOutput>.Remove(TOutput item)
    {
      throw new NotSupportedException();
    }
    
    public IEnumerator<TOutput> GetEnumerator()
    {
      for (int i = 0; i < this.Count; i++) {
        yield return this[i];
      }
    }
    
    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
    {
      return GetEnumerator();
    }
  }
  
  public sealed class ProjectedList<TContext, TInput, TOutput> : IList<TOutput> where TOutput : class
  {
    readonly IList<TInput> input;
    readonly TContext context;
    readonly Func<TContext, TInput, TOutput> projection;
    readonly TOutput[] items;
    
    public ProjectedList(TContext context, IList<TInput> input, Func<TContext, TInput, TOutput> projection)
    {
      if (input == null)
        throw new ArgumentNullException("input");
      if (projection == null)
        throw new ArgumentNullException("projection");
      this.input = input;
      this.context = context;
      this.projection = projection;
      this.items = new TOutput[input.Count];
    }
    
    public TOutput this[int index] {
      get {
        TOutput output = LazyInit.VolatileRead(ref items[index]);
        if (output != null) {
          return output;
        }
        return LazyInit.GetOrSet(ref items[index], projection(context, input[index]));
      }
    }
    
    TOutput IList<TOutput>.this[int index] {
      get { return this[index]; }
      set {
        throw new NotSupportedException();
      }
    }
    
    public int Count {
      get { return items.Length; }
    }
    
    bool ICollection<TOutput>.IsReadOnly {
      get { return true; }
    }
    
    int IList<TOutput>.IndexOf(TOutput item)
    {
      var comparer = EqualityComparer<TOutput>.Default;
      for (int i = 0; i < this.Count; i++) {
        if (comparer.Equals(this[i], item))
          return i;
      }
      return -1;
    }
    
    void IList<TOutput>.Insert(int index, TOutput item)
    {
      throw new NotSupportedException();
    }
    
    void IList<TOutput>.RemoveAt(int index)
    {
      throw new NotSupportedException();
    }
    
    void ICollection<TOutput>.Add(TOutput item)
    {
      throw new NotSupportedException();
    }
    
    void ICollection<TOutput>.Clear()
    {
      throw new NotSupportedException();
    }
    
    bool ICollection<TOutput>.Contains(TOutput item)
    {
      var comparer = EqualityComparer<TOutput>.Default;
      for (int i = 0; i < this.Count; i++) {
        if (comparer.Equals(this[i], item))
          return true;
      }
      return false;
    }
    
    void ICollection<TOutput>.CopyTo(TOutput[] array, int arrayIndex)
    {
      for (int i = 0; i < items.Length; i++) {
        array[arrayIndex + i] = this[i];
      }
    }
    
    bool ICollection<TOutput>.Remove(TOutput item)
    {
      throw new NotSupportedException();
    }
    
    public IEnumerator<TOutput> GetEnumerator()
    {
      for (int i = 0; i < this.Count; i++) {
        yield return this[i];
      }
    }
    
    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
    {
      return GetEnumerator();
    }
  }
}