// 
// SequenceGenerator.cs
// 
// Authors:
//	Alexander Chebaturkin (chebaturkin@gmail.com)
// 
// Copyright (C) 2011 Alexander Chebaturkin
// 
// 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.Collections;
using System.Collections.Generic;
using Mono.CodeContracts.Static.DataStructures;

namespace Mono.CodeContracts.Static.Analysis.StackAnalysis {
	class SequenceGenerator : IIndexable<int>, IEnumerable<int> {
		private readonly short count;
		private readonly short from;

		public SequenceGenerator (int from, int count)
		{
			this.from = checked((short) from);
			this.count = checked((short) count);
		}

		#region Implementation of IIndexable<int>
		public int Count {
			get { return this.count; }
		}

		public int this [int index] {
			get { return this.from + index; }
		}
		#endregion

		#region Implementation of IEnumerable
		public IEnumerator<int> GetEnumerator ()
		{
			for (int i = 0; i < this.count; i++)
				yield return this [i];
		}

		IEnumerator IEnumerable.GetEnumerator ()
		{
			return GetEnumerator ();
		}
		#endregion
	}
}