// 
// IImmutableSet.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;
using System.Collections.Generic;
using System.IO;

namespace Mono.CodeContracts.Static.DataStructures {
	interface IImmutableSet<T> {
		T Any { get; }
		int Count { get; }
		IEnumerable<T> Elements { get; }
		IImmutableSet<T> Add (T item);
        IImmutableSet<T> AddRange (IEnumerable<T> item);
		IImmutableSet<T> Remove (T item);
		bool Contains (T item);
		bool IsContainedIn (IImmutableSet<T> that);
		IImmutableSet<T> Intersect (IImmutableSet<T> that);
		IImmutableSet<T> Union (IImmutableSet<T> that);
		void Visit (Action<T> visitor);
		void Dump (TextWriter tw);
	}
}