// Licensed to the .NET Foundation under one or more agreements. // The .NET Foundation licenses this file to you under the Apache 2.0 License. // See the LICENSE file in the project root for more information. using System; using System.Collections.Generic; using System.Linq; using System.Threading.Tasks; namespace System.Linq { public static partial class EnumerableEx { /// /// Creates a sequence whose termination or disposal of an enumerator causes a finally action to be executed. /// /// Source sequence element type. /// Source sequence. /// Action to run upon termination of the sequence, or when an enumerator is disposed. /// Source sequence with guarantees on the invocation of the finally action. public static IEnumerable Finally(this IEnumerable source, Action finallyAction) { if (source == null) throw new ArgumentNullException(nameof(source)); if (finallyAction == null) throw new ArgumentNullException(nameof(finallyAction)); return source.Finally_(finallyAction); } private static IEnumerable Finally_(this IEnumerable source, Action finallyAction) { try { foreach (var item in source) yield return item; } finally { finallyAction(); } } } }