mono/mcs/class/System.Core/System.Linq.Parallel.QueryNodes/WrapHelper.cs

//
// WrapHelper.cs
//
// Author:
//       Jérémie "Garuma" Laval <[email protected]>
//
// Copyright (c) 2010 Jérémie "Garuma" Laval
//
// 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.Linq;
using System.Collections;
using System.Collections.Generic;

namespace System.Linq.Parallel.QueryNodes
{
	internal static class WrapHelper
	{
		class EnumeratorWrapper<TEnum> : IEnumerable<TEnum>
		{
			IEnumerator<TEnum> enumerator;

			public EnumeratorWrapper (IEnumerator<TEnum> enumerator)
			{
				this.enumerator = enumerator;
			}

			public IEnumerator<TEnum> GetEnumerator ()
			{
				return enumerator;
			}

			IEnumerator IEnumerable.GetEnumerator ()
			{
				return (IEnumerator)enumerator;
			}
		}

		internal static IList<IEnumerable<TEnum>> Wrap<TEnum> (this IList<IEnumerator<TEnum>> src)
		{
			var list = new List<IEnumerable<TEnum>> (src.Count);
			foreach (var iterator in src)
				list.Add (new EnumeratorWrapper<TEnum> (iterator));
			return list;
		}
	}
}