Newtonsoft.Json\Utilities\BidirectionalDictionary.cs

#region License

// Copyright (c) 2007 James Newton-King

//

// 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.

#endregion

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Newtonsoft.Json.Utilities

{

  internal class BidirectionalDictionary<TFirst, TSecond>

  {

    private readonly IDictionary<TFirst, TSecond> _firstToSecond;

    private readonly IDictionary<TSecond, TFirst> _secondToFirst;

    public BidirectionalDictionary()

      : this(EqualityComparer<TFirst>.Default, EqualityComparer<TSecond>.Default)

    {

    }

    public BidirectionalDictionary(IEqualityComparer<TFirst> firstEqualityComparer, IEqualityComparer<TSecond> secondEqualityComparer)

    {

      _firstToSecond = new Dictionary<TFirst, TSecond>(firstEqualityComparer);

      _secondToFirst = new Dictionary<TSecond, TFirst>(secondEqualityComparer);

    }

    public void Add(TFirst first, TSecond second)

    {

      if (_firstToSecond.ContainsKey(first) || _secondToFirst.ContainsKey(second))

      {

        throw new ArgumentException("Duplicate first or second");

      }

      _firstToSecond.Add(first, second);

      _secondToFirst.Add(second, first);

    }

    public bool TryGetByFirst(TFirst first, out TSecond second)

    {

      return _firstToSecond.TryGetValue(first, out second);

    }

    public bool TryGetBySecond(TSecond second, out TFirst first)

    {

      return _secondToFirst.TryGetValue(second, out first);

    }

  }

}