//
// Queryable.cs
//
// Authors:
//  Marek Safar (marek.safar@gmail.com)
//  Alejandro Serrano "Serras" (trupill@yahoo.es)
//  Jb Evain (jbevain@novell.com)
//  Andreas Noever (andreas.noever@gmail.com)
//
// Copyright (C) 2008 Novell, Inc (http://www.novell.com)
//
// 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;
using System.Collections.Generic;
using System.Linq.Expressions;
using System.Reflection;
using System.Linq;

namespace System.Linq {

	public static class Queryable {

		static MethodInfo MakeGeneric (MethodBase method, params Type [] parameters)
		{
			return ((MethodInfo) method).MakeGenericMethod (parameters);
		}

		static Expression StaticCall (MethodInfo method, params Expression [] expressions)
		{
			return Expression.Call (null, method, expressions);
		}

		static TRet Execute<TRet, TSource> (this IQueryable<TSource> source, MethodBase current)
		{
			return source.Provider.Execute<TRet> (
				StaticCall (
					MakeGeneric (current, typeof (TSource)),
					source.Expression));
		}

		#region Aggregate

		public static TSource Aggregate<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, TSource, TSource>> func)
		{
			Check.SourceAndFunc (source, func);
			return source.Provider.Execute<TSource> (
			StaticCall (
				MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
				source.Expression,
				Expression.Quote (func)));
		}

		public static TAccumulate Aggregate<TSource, TAccumulate> (this IQueryable<TSource> source, TAccumulate seed, Expression<Func<TAccumulate, TSource, TAccumulate>> func)
		{
			Check.SourceAndFunc (source, func);
			return source.Provider.Execute<TAccumulate> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TAccumulate)),
					source.Expression,
					Expression.Constant (seed),
					Expression.Quote (func)));
		}

		public static TResult Aggregate<TSource, TAccumulate, TResult> (this IQueryable<TSource> source, TAccumulate seed, Expression<Func<TAccumulate, TSource, TAccumulate>> func, Expression<Func<TAccumulate, TResult>> selector)
		{
			Check.SourceAndFuncAndSelector (source, func, selector);
			return source.Provider.Execute<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TAccumulate), typeof (TResult)),
					source.Expression,
					Expression.Constant (seed),
					Expression.Quote (func),
					Expression.Quote (selector)));
		}

		#endregion

		#region All

		public static bool All<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.Execute<bool> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		#endregion

		#region Any

		public static bool Any<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.Execute<bool> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		public static bool Any<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.Execute<bool> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		#endregion

		#region AsQueryable

		public static IQueryable<TElement> AsQueryable<TElement> (this IEnumerable<TElement> source)
		{
			if (source == null)
				throw new ArgumentNullException ("source");

			var queryable = source as IQueryable<TElement>;
			if (queryable != null)
				return queryable;

			return new QueryableEnumerable<TElement> (source);
		}

		public static IQueryable AsQueryable (this IEnumerable source)
		{
			if (source == null)
				throw new ArgumentNullException ("source");

			var queryable = source as IQueryable;
			if (queryable != null)
				return queryable;

			var type = source.GetType ();

			if (!type.IsGenericImplementationOf (typeof (IEnumerable<>)))
				throw new ArgumentException ("source is not IEnumerable<>");

			return (IQueryable) Activator.CreateInstance (
				typeof (QueryableEnumerable<>).MakeGenericType (type.GetFirstGenericArgument ()), source);
		}

		#endregion

		#region Average

		public static double Average (this IQueryable<int> source)
		{
			Check.Source (source);

			return source.Provider.Execute<double>(
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static double? Average(this IQueryable<int?> source)
		{
			Check.Source (source);

			return source.Provider.Execute<double?>(
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static double Average(this IQueryable<long> source)
		{
			Check.Source (source);

			return source.Provider.Execute<double>(
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static double? Average(this IQueryable<long?> source)
		{
			Check.Source (source);

			return source.Provider.Execute<double?>(
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static float Average(this IQueryable<float> source)
		{
			Check.Source (source);

			return source.Provider.Execute<float>(
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static float? Average(this IQueryable<float?> source)
		{
			Check.Source (source);

			return source.Provider.Execute<float?>(
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static double Average (this IQueryable<double> source)
		{
			Check.Source (source);

			return source.Provider.Execute<double> (
				StaticCall (
				(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static double? Average (this IQueryable<double?> source)
		{
			Check.Source (source);

			return source.Provider.Execute<double?> (
				StaticCall (
				(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static decimal Average(this IQueryable<decimal> source)
		{
			Check.Source (source);

			return source.Provider.Execute<decimal>(
				StaticCall (
				(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static decimal? Average(this IQueryable<decimal?> source)
		{
			Check.Source (source);

			return source.Provider.Execute<decimal?>(
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static double Average<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, int>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<double>(
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static double? Average<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, int?>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<double?>(
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static double Average<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, long>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<double>(
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static double? Average<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, long?>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<double?>(
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static float Average<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, float>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<float>(
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static float? Average<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, float?>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<float?>(
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static double Average<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, double>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<double> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static double? Average<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, double?>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<double?> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static decimal Average<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, decimal>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<decimal>(
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static decimal? Average<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, decimal?>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<decimal?>(
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		#endregion

		#region Cast

		public static IQueryable<TResult> Cast<TResult> (this IQueryable source)
		{
			Check.Source (source);

			return (IQueryable<TResult>) source.Provider.CreateQuery (
				StaticCall (MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TResult)),
					source.Expression));
		}

		#endregion

		#region Concat

		public static IQueryable<TSource> Concat<TSource> (this IQueryable<TSource> source1, IEnumerable<TSource> source2)
		{
			Check.Source1AndSource2 (source1, source2);

			return source1.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source1.Expression,
					Expression.Constant (source2)));
		}

		#endregion

		#region Contains

		public static bool Contains<TSource> (this IQueryable<TSource> source, TSource item)
		{
			Check.Source (source);

			return source.Provider.Execute<bool> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Constant (item)));
		}

		public static bool Contains<TSource> (this IQueryable<TSource> source, TSource item, IEqualityComparer<TSource> comparer)
		{
			Check.Source (source);

			return source.Provider.Execute<bool> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Constant (item),
					Expression.Constant (comparer)));
		}

		#endregion

		#region Count

		public static int Count<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Execute<int, TSource> (MethodBase.GetCurrentMethod ());
		}

		public static int Count<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.Execute<int> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		#endregion

		#region DefaultIfEmpty

		public static IQueryable<TSource> DefaultIfEmpty<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		public static IQueryable<TSource> DefaultIfEmpty<TSource> (this IQueryable<TSource> source, TSource defaultValue)
		{
			Check.Source (source);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Constant (defaultValue)));
		}

		#endregion

		#region Distinct

		public static IQueryable<TSource> Distinct<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		public static IQueryable<TSource> Distinct<TSource> (this IQueryable<TSource> source, IEqualityComparer<TSource> comparer)
		{
			Check.Source (source);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Constant (comparer)));
		}

		#endregion

		#region ElementAt

		public static TSource ElementAt<TSource> (this IQueryable<TSource> source, int index)
		{
			Check.Source (source);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Constant (index)));
		}

		#endregion

		#region ElementAtOrDefault

		public static TSource ElementAtOrDefault<TSource> (this IQueryable<TSource> source, int index)
		{
			Check.Source (source);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Constant (index)));
		}

		#endregion

		#region Except

		public static IQueryable<TSource> Except<TSource> (this IQueryable<TSource> source1, IEnumerable<TSource> source2)
		{
			Check.Source1AndSource2 (source1, source2);

			return source1.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source1.Expression,
					Expression.Constant (source2)));
		}

		public static IQueryable<TSource> Except<TSource> (this IQueryable<TSource> source1, IEnumerable<TSource> source2, IEqualityComparer<TSource> comparer)
		{
			Check.Source1AndSource2 (source1, source2);

			return source1.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source1.Expression,
					Expression.Constant (source2),
					Expression.Constant (comparer)));
		}

		#endregion

		#region First

		public static TSource First<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		public static TSource First<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		#endregion

		#region FirstOrDefault

		public static TSource FirstOrDefault<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		public static TSource FirstOrDefault<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		#endregion

		#region GroupBy

		public static IQueryable<IGrouping<TKey, TSource>> GroupBy<TSource, TKey> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector)
		{
			Check.SourceAndKeySelector (source, keySelector);

			return source.Provider.CreateQuery<IGrouping<TKey, TSource>> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey)),
					source.Expression,
					Expression.Quote (keySelector)));
		}
		public static IQueryable<IGrouping<TKey, TSource>> GroupBy<TSource, TKey> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, IEqualityComparer<TKey> comparer)
		{
			Check.SourceAndKeySelector (source, keySelector);

			return source.Provider.CreateQuery<IGrouping<TKey, TSource>> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey)),
					source.Expression,
					Expression.Quote (keySelector),
					Expression.Constant (comparer)));
		}
		public static IQueryable<IGrouping<TKey, TElement>> GroupBy<TSource, TKey, TElement> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, Expression<Func<TSource, TElement>> elementSelector)
		{
			Check.SourceAndKeyElementSelectors (source, keySelector, elementSelector);

			return source.Provider.CreateQuery<IGrouping<TKey, TElement>>(
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey), typeof (TElement)),
					source.Expression,
					Expression.Quote (keySelector),
					Expression.Quote (elementSelector)));
		}
		public static IQueryable<TResult> GroupBy<TSource, TKey, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, Expression<Func<TKey, IEnumerable<TSource>, TResult>> resultSelector)
		{
			Check.SourceAndKeyResultSelectors (source, keySelector, resultSelector);

			return source.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey), typeof (TResult)),
					source.Expression,
					Expression.Quote (keySelector),
					Expression.Quote (resultSelector)));
		}
		public static IQueryable<IGrouping<TKey, TElement>> GroupBy<TSource, TKey, TElement> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, Expression<Func<TSource, TElement>> elementSelector, IEqualityComparer<TKey> comparer)
		{
			Check.SourceAndKeyElementSelectors (source, keySelector, elementSelector);

			return source.Provider.CreateQuery<IGrouping<TKey, TElement>> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey), typeof (TElement)),
					source.Expression,
					Expression.Quote (keySelector),
					Expression.Quote (elementSelector),
					Expression.Constant (comparer)));
		}
		public static IQueryable<TResult> GroupBy<TSource, TKey, TElement, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, Expression<Func<TSource, TElement>> elementSelector, Expression<Func<TKey, IEnumerable<TElement>, TResult>> resultSelector)
		{
			Check.GroupBySelectors (source, keySelector, elementSelector, resultSelector);

			return source.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey), typeof (TElement), typeof (TResult)),
					source.Expression,
					Expression.Quote (keySelector),
					Expression.Quote (elementSelector),
					Expression.Quote (resultSelector)));
		}

		public static IQueryable<TResult> GroupBy<TSource, TKey, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, Expression<Func<TKey, IEnumerable<TSource>, TResult>> resultSelector, IEqualityComparer<TKey> comparer)
		{
			Check.SourceAndKeyResultSelectors (source, keySelector, resultSelector);

			return source.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey), typeof (TResult)),
					source.Expression,
					Expression.Quote (keySelector),
					Expression.Quote (resultSelector),
					Expression.Constant (comparer)));
		}
		public static IQueryable<TResult> GroupBy<TSource, TKey, TElement, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, Expression<Func<TSource, TElement>> elementSelector, Expression<Func<TKey, IEnumerable<TElement>, TResult>> resultSelector, IEqualityComparer<TKey> comparer)
		{
			Check.GroupBySelectors (source, keySelector, elementSelector, resultSelector);

			return source.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey), typeof (TElement), typeof (TResult)),
					source.Expression,
					Expression.Quote (keySelector),
					Expression.Quote (elementSelector),
					Expression.Quote (resultSelector),
					Expression.Constant (comparer)));
		}
		#endregion

		#region GroupJoin

		public static IQueryable<TResult> GroupJoin<TOuter, TInner, TKey, TResult> (this IQueryable<TOuter> outer, IEnumerable<TInner> inner, Expression<Func<TOuter, TKey>> outerKeySelector, Expression<Func<TInner, TKey>> innerKeySelector, Expression<Func<TOuter, IEnumerable<TInner>, TResult>> resultSelector)
		{
			if (outer == null)
				throw new ArgumentNullException ("outer");
			if (inner == null)
				throw new ArgumentNullException ("inner");
			if (outerKeySelector == null)
				throw new ArgumentNullException ("outerKeySelector");
			if (innerKeySelector == null)
				throw new ArgumentNullException ("innerKeySelector");
			if (resultSelector == null)
				throw new ArgumentNullException ("resultSelector");

			return outer.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TOuter), typeof (TInner), typeof (TKey), typeof (TResult)),
					outer.Expression,
					Expression.Constant (inner),
					Expression.Quote (outerKeySelector),
					Expression.Quote (innerKeySelector),
					Expression.Quote (resultSelector)));
		}

		public static IQueryable<TResult> GroupJoin<TOuter, TInner, TKey, TResult> (this IQueryable<TOuter> outer, IEnumerable<TInner> inner, Expression<Func<TOuter, TKey>> outerKeySelector, Expression<Func<TInner, TKey>> innerKeySelector, Expression<Func<TOuter, IEnumerable<TInner>, TResult>> resultSelector, IEqualityComparer<TKey> comparer)
		{
			if (outer == null)
				throw new ArgumentNullException ("outer");
			if (inner == null)
				throw new ArgumentNullException ("inner");
			if (outerKeySelector == null)
				throw new ArgumentNullException ("outerKeySelector");
			if (innerKeySelector == null)
				throw new ArgumentNullException ("innerKeySelector");
			if (resultSelector == null)
				throw new ArgumentNullException ("resultSelector");

			return outer.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TOuter), typeof (TInner), typeof (TKey), typeof (TResult)),
					outer.Expression,
					Expression.Constant (inner),
					Expression.Quote (outerKeySelector),
					Expression.Quote (innerKeySelector),
					Expression.Quote (resultSelector),
					Expression.Constant (comparer)));
		}

		#endregion

		#region Intersect

		public static IQueryable<TSource> Intersect<TSource> (this IQueryable<TSource> source1, IEnumerable<TSource> source2)
		{
			Check.Source1AndSource2 (source1, source2);

			return source1.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source1.Expression,
					Expression.Constant (source2)));
		}

		public static IQueryable<TSource> Intersect<TSource> (this IQueryable<TSource> source1, IEnumerable<TSource> source2, IEqualityComparer<TSource> comparer)
		{
			Check.Source1AndSource2 (source1, source2);

			return source1.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source1.Expression,
					Expression.Constant (source2),
					Expression.Constant (comparer)));
		}

		#endregion

		#region Join

		public static IQueryable<TResult> Join<TOuter, TInner, TKey, TResult> (this IQueryable<TOuter> outer, IEnumerable<TInner> inner, Expression<Func<TOuter, TKey>> outerKeySelector, Expression<Func<TInner, TKey>> innerKeySelector, Expression<Func<TOuter, TInner, TResult>> resultSelector)
		{
			Check.JoinSelectors (outer, inner, outerKeySelector, innerKeySelector, resultSelector);

			return outer.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TOuter), typeof (TInner), typeof (TKey), typeof (TResult)),
					outer.Expression,
					Expression.Constant (inner),
					Expression.Quote (outerKeySelector),
					Expression.Quote (innerKeySelector),
					Expression.Quote (resultSelector)));
		}

		public static IQueryable<TResult> Join<TOuter, TInner, TKey, TResult> (this IQueryable<TOuter> outer, IEnumerable<TInner> inner, Expression<Func<TOuter, TKey>> outerKeySelector, Expression<Func<TInner, TKey>> innerKeySelector, Expression<Func<TOuter, TInner, TResult>> resultSelector, IEqualityComparer<TKey> comparer)
		{
			Check.JoinSelectors (outer, inner, outerKeySelector, innerKeySelector, resultSelector);

			return outer.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TOuter), typeof (TInner), typeof (TKey), typeof (TResult)),
					outer.Expression,
					Expression.Constant (inner),
					Expression.Quote (outerKeySelector),
					Expression.Quote (innerKeySelector),
					Expression.Quote (resultSelector),
					Expression.Constant (comparer)));
		}


		#endregion

		#region Last

		public static TSource Last<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		public static TSource Last<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		#endregion

		#region LastOrDefault

		public static TSource LastOrDefault<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		public static TSource LastOrDefault<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		#endregion

		#region LongCount

		public static long LongCount<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Execute<long, TSource> (MethodBase.GetCurrentMethod ());
		}

		public static long LongCount<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.Execute<long> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		#endregion

		#region Max

		public static TSource Max<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		public static TResult Max<TSource, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, TResult>> selector)
		{
			Check.Source (source);

			return source.Provider.Execute<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TResult)),
					source.Expression,
					Expression.Quote (selector)));
		}


		#endregion

		#region Min

		public static TSource Min<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		public static TResult Min<TSource, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, TResult>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TResult)),
					source.Expression,
					Expression.Quote (selector)));
		}


		#endregion

		#region OfType

		public static IQueryable<TResult> OfType<TResult> (this IQueryable source)
		{
			Check.Source (source);

			return (IQueryable<TResult>) source.Provider.CreateQuery (
			StaticCall (
				MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TResult)),
				source.Expression));
		}

		#endregion

		#region OrderBy

		public static IOrderedQueryable<TSource> OrderBy<TSource, TKey> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector)
		{
			Check.SourceAndKeySelector (source, keySelector);

			return (IOrderedQueryable<TSource>) source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey)),
					source.Expression,
					Expression.Quote (keySelector)));
		}

		public static IOrderedQueryable<TSource> OrderBy<TSource, TKey> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, IComparer<TKey> comparer)
		{
			Check.SourceAndKeySelector (source, keySelector);

			return (IOrderedQueryable<TSource>) source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey)),
					source.Expression,
					Expression.Quote (keySelector),
					Expression.Constant (comparer)));
		}

		#endregion

		#region OrderByDescending

		public static IOrderedQueryable<TSource> OrderByDescending<TSource, TKey> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector)
		{
			Check.SourceAndKeySelector (source, keySelector);

			return (IOrderedQueryable<TSource>) source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey)),
					source.Expression,
					Expression.Quote (keySelector)));
		}

		public static IOrderedQueryable<TSource> OrderByDescending<TSource, TKey> (this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, IComparer<TKey> comparer)
		{
			Check.SourceAndKeySelector (source, keySelector);

			return (IOrderedQueryable<TSource>) source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey)),
					source.Expression,
					Expression.Quote (keySelector),
					Expression.Constant (comparer)));
		}

		#endregion

		#region Reverse

		public static IQueryable<TSource> Reverse<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		#endregion

		#region Select

		public static IQueryable<TResult> Select<TSource, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, TResult>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TResult)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static IQueryable<TResult> Select<TSource, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, int, TResult>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TResult)),
					source.Expression,
					Expression.Quote (selector)));
		}

		#endregion

		#region SelectMany

		public static IQueryable<TResult> SelectMany<TSource, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, IEnumerable<TResult>>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TResult)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static IQueryable<TResult> SelectMany<TSource, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, int, IEnumerable<TResult>>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TResult)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static IQueryable<TResult> SelectMany<TSource, TCollection, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, int, IEnumerable<TCollection>>> collectionSelector, Expression<Func<TSource, TCollection, TResult>> resultSelector)
		{
			Check.SourceAndCollectionSelectorAndResultSelector (source, collectionSelector, resultSelector);

			return source.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TCollection), typeof (TResult)),
					source.Expression,
					Expression.Quote (collectionSelector),
					Expression.Quote (resultSelector)));
		}

		public static IQueryable<TResult> SelectMany<TSource, TCollection, TResult> (this IQueryable<TSource> source, Expression<Func<TSource, IEnumerable<TCollection>>> collectionSelector, Expression<Func<TSource, TCollection, TResult>> resultSelector)
		{
			Check.SourceAndCollectionSelectorAndResultSelector (source, collectionSelector, resultSelector);

			return source.Provider.CreateQuery<TResult> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TCollection), typeof (TResult)),
					source.Expression,
					Expression.Quote (collectionSelector),
					Expression.Quote (resultSelector)));
		}

		#endregion

		#region SequenceEqual

		public static bool SequenceEqual<TSource> (this IQueryable<TSource> source1, IEnumerable<TSource> source2)
		{
			Check.Source1AndSource2 (source1, source2);

			return source1.Provider.Execute<bool> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source1.Expression,
					Expression.Constant (source2)));
		}

		public static bool SequenceEqual<TSource> (this IQueryable<TSource> source1, IEnumerable<TSource> source2, IEqualityComparer<TSource> comparer)
		{
			Check.Source1AndSource2 (source1, source2);

			return source1.Provider.Execute<bool> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source1.Expression,
					Expression.Constant (source2),
					Expression.Constant (comparer)));
		}

		#endregion

		#region Single

		public static TSource Single<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		public static TSource Single<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		#endregion

		#region SingleOrDefault

		public static TSource SingleOrDefault<TSource> (this IQueryable<TSource> source)
		{
			Check.Source (source);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression));
		}

		public static TSource SingleOrDefault<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.Execute<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		#endregion

		#region Skip

		public static IQueryable<TSource> Skip<TSource> (this IQueryable<TSource> source, int count)
		{
			Check.Source (source);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Constant (count)));
		}

		#endregion

		#region SkipWhile

		public static IQueryable<TSource> SkipWhile<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		public static IQueryable<TSource> SkipWhile<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, int, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}


		#endregion

		#region Sum


		public static int Sum<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, int>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<int> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static int? Sum<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, int?>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<int?> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static long Sum<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, long>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<long> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static long? Sum<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, long?>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<long?> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static float Sum<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, float>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<float> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static float? Sum<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, float?>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<float?> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static double Sum<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, double>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<double> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static double? Sum<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, double?>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<double?> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static decimal Sum<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, decimal>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<decimal> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static decimal? Sum<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, decimal?>> selector)
		{
			Check.SourceAndSelector (source, selector);

			return source.Provider.Execute<decimal?> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (selector)));
		}

		public static int Sum (this IQueryable<int> source)
		{
			Check.Source (source);

			return source.Provider.Execute<int> (
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static int? Sum (this IQueryable<int?> source)
		{
			Check.Source (source);

			return source.Provider.Execute<int?> (
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}



		public static long Sum (this IQueryable<long> source)
		{
			Check.Source (source);

			return source.Provider.Execute<long> (
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}



		public static long? Sum (this IQueryable<long?> source)
		{
			Check.Source (source);

			return source.Provider.Execute<long?> (
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static float Sum (this IQueryable<float> source)
		{
			Check.Source (source);

			return source.Provider.Execute<float> (
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}

		public static float? Sum (this IQueryable<float?> source)
		{
			Check.Source (source);

			return source.Provider.Execute<float?> (
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}


		public static double Sum (this IQueryable<double> source)
		{
			Check.Source (source);

			return source.Provider.Execute<double> (
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}



		public static double? Sum (this IQueryable<double?> source)
		{
			Check.Source (source);

			return source.Provider.Execute<double?> (
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}


		public static decimal Sum (this IQueryable<decimal> source)
		{
			Check.Source (source);

			return source.Provider.Execute<decimal> (
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}



		public static decimal? Sum (this IQueryable<decimal?> source)
		{
			Check.Source (source);

			return source.Provider.Execute<decimal?> (
				StaticCall (
					(MethodInfo) MethodBase.GetCurrentMethod (),
					source.Expression));
		}



		#endregion

		#region Take

		public static IQueryable<TSource> Take<TSource> (this IQueryable<TSource> source, int count)
		{
			Check.Source (source);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Constant (count)));
		}

		#endregion

		#region TakeWhile

		public static IQueryable<TSource> TakeWhile<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		public static IQueryable<TSource> TakeWhile<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, int, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		#endregion

		#region ThenBy

		public static IOrderedQueryable<TSource> ThenBy<TSource, TKey> (this IOrderedQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector)
		{
			Check.SourceAndKeySelector (source, keySelector);

			return (IOrderedQueryable<TSource>) source.Provider.CreateQuery (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey)),
					source.Expression,
					Expression.Quote (keySelector)));
		}

		public static IOrderedQueryable<TSource> ThenBy<TSource, TKey> (this IOrderedQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, IComparer<TKey> comparer)
		{
			Check.SourceAndKeySelector (source, keySelector);

			return (IOrderedQueryable<TSource>) source.Provider.CreateQuery (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey)),
					source.Expression,
					Expression.Quote (keySelector),
					Expression.Constant (comparer)));
		}

		#endregion

		#region ThenByDescending

		public static IOrderedQueryable<TSource> ThenByDescending<TSource, TKey> (this IOrderedQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector)
		{
			Check.SourceAndKeySelector (source, keySelector);

			return (IOrderedQueryable<TSource>) source.Provider.CreateQuery (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey)),
					source.Expression,
					Expression.Quote (keySelector)));
		}

		public static IOrderedQueryable<TSource> ThenByDescending<TSource, TKey> (this IOrderedQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, IComparer<TKey> comparer)
		{
			Check.SourceAndKeySelector (source, keySelector);

			return (IOrderedQueryable<TSource>) source.Provider.CreateQuery (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource), typeof (TKey)),
					source.Expression,
					Expression.Quote (keySelector),
					Expression.Constant (comparer)));
		}

		#endregion

		#region Union

		public static IQueryable<TSource> Union<TSource> (this IQueryable<TSource> source1, IEnumerable<TSource> source2)
		{
			Check.Source1AndSource2 (source1, source2);

			return source1.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source1.Expression,
					Expression.Constant (source2)));
		}

		public static IQueryable<TSource> Union<TSource>(this IQueryable<TSource> source1, IEnumerable<TSource> source2, IEqualityComparer<TSource> comparer)
		{
			Check.Source1AndSource2 (source1, source2);

			return source1.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source1.Expression,
					Expression.Constant (source2),
					Expression.Constant (comparer)));
		}


		#endregion

		#region Where

		public static IQueryable<TSource> Where<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}

		public static IQueryable<TSource> Where<TSource> (this IQueryable<TSource> source, Expression<Func<TSource, int, bool>> predicate)
		{
			Check.SourceAndPredicate (source, predicate);

			return source.Provider.CreateQuery<TSource> (
				StaticCall (
					MakeGeneric (MethodBase.GetCurrentMethod (), typeof (TSource)),
					source.Expression,
					Expression.Quote (predicate)));
		}


		#endregion

	}
}