Expand Choose implementation (morelinq#575)

atifaziz · May 1, 2019 · b06309d · b06309d
1 parent 3351921
commit b06309d
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Showing 2 changed files with 11 additions and 7 deletions.
diff --git a/MoreLinq/Choose.cs b/MoreLinq/Choose.cs
@@ -51,16 +51,20 @@ static partial class MoreEnumerable
         /// </example>
 
         public static IEnumerable<TResult> Choose<T, TResult>(this IEnumerable<T> source,
-            Func<T, (bool IsSome, TResult Value)> chooser)
+            Func<T, (bool, TResult)> chooser)
         {
             if (source == null) throw new ArgumentNullException(nameof(source));
             if (chooser == null) throw new ArgumentNullException(nameof(chooser));
 
-            return
-                from item in source
-                select chooser(item) into e
-                where e.IsSome
-                select e.Value;
+            return _(); IEnumerable<TResult> _()
+            {
+                foreach (var item in source)
+                {
+                    var (some, value) = chooser(item);
+                    if (some)
+                        yield return value;
+                }
+            }
         }
     }
 }
diff --git a/MoreLinq/Extensions.g.cs b/MoreLinq/Extensions.g.cs
@@ -744,7 +744,7 @@ public static partial class ChooseExtension
         /// </example>
 
         public static IEnumerable<TResult> Choose<T, TResult>(this IEnumerable<T> source,
-            Func<T, (bool IsSome, TResult Value)> chooser)
+            Func<T, (bool, TResult)> chooser)
             => MoreEnumerable.Choose(source, chooser);
 
     }