using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using ICSharpCode.NRefactory.CSharp;

namespace System.Collections.Generic

{

static class CollectionExtensions

{

public static bool Parallel = true;

public static Action ParallelPreAction { get; set; }

public static void ForEachParallel<T>(this IEnumerable<T> items, Action<T> action, bool parallel)

{

if (parallel)

{

Action<T> action2 = action;

if (ParallelPreAction != null)

action2 = t => {ParallelPreAction(); action(t);};

items.AsParallel().ForAll(action2);

}

else

items.ForEach(action);

}

public static void ForEachParallel<T>(this IEnumerable<T> items, Action<T> action)

{

items.ForEachParallel(action, Parallel);

}

public static IEnumerable<T> NotNull<T>(this IEnumerable<T> list)

{

if (list == null)

return Enumerable.Empty<T>();

return list;

}

public static R IfNotNull<T, R>(this T obj, Func<T, R> func) where T : class

{

if (obj != null)

return func(obj);

return default(R);

}

public static bool Matches<T>(this IEnumerable<T> list, IEnumerable<T> list2, Func<T, T, bool> match)

{

var x = list.GetEnumerator();

var y = list2.GetEnumerator();

while (true)

{

var x1 = x.MoveNext();

var x2 = y.MoveNext();

if (x1 != x2)

return false;

if (!x1)

return true;

if (!match(x.Current, y.Current))

return false;

}

}

}

}