From 64424297274f037afda5eaa785b5815305d29335 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nils=20L=C3=BCck?= <nils.luck@outlook.com>
Date: Mon, 16 Oct 2017 09:02:02 +0200
Subject: [PATCH] Minor optimizations to collection flattening

---
 .../Collections/OptionCollectionExtensions.cs | 22 ++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/src/Optional/Collections/OptionCollectionExtensions.cs b/src/Optional/Collections/OptionCollectionExtensions.cs
index f414ffe..da6c77f 100644
--- a/src/Optional/Collections/OptionCollectionExtensions.cs
+++ b/src/Optional/Collections/OptionCollectionExtensions.cs
@@ -18,7 +18,14 @@ public static class OptionCollectionExtensions
         public static IEnumerable<T> Values<T>(this IEnumerable<Option<T>> source)
         {
             if (source == null) throw new ArgumentNullException(nameof(source));
-            return source.SelectMany(option => option.ToEnumerable());
+
+            foreach (var option in source)
+            {
+                if (option.HasValue)
+                {
+                    yield return option.Value;
+                }
+            }
         }
 
         /// <summary>
@@ -30,7 +37,14 @@ public static IEnumerable<T> Values<T>(this IEnumerable<Option<T>> source)
         public static IEnumerable<T> Values<T, TException>(this IEnumerable<Option<T, TException>> source)
         {
             if (source == null) throw new ArgumentNullException(nameof(source));
-            return source.SelectMany(option => option.ToEnumerable());
+
+            foreach (var option in source)
+            {
+                if (option.HasValue)
+                {
+                    yield return option.Value;
+                }
+            }
         }
 
         /// <summary>
@@ -43,15 +57,13 @@ public static IEnumerable<TException> Exceptions<T, TException>(this IEnumerable
         {
             if (source == null) throw new ArgumentNullException(nameof(source));
 
-            IEnumerable<TException> ExceptionToEnumerable(Option<T, TException> option)
+            foreach (var option in source)
             {
                 if (!option.HasValue)
                 {
                     yield return option.Exception;
                 }
             }
-
-            return source.SelectMany(ExceptionToEnumerable);
         }
 
         /// <summary>