添加Append方法

Sanchime.Functional/Extensions/Either.cs

@@ -64,4 +64,6 @@ public static class EitherExtension
 
     public static Either<L, Unit> ForEach<L, R>(this Either<L, R> either, Action<R> action)
         => either.Map(action.ToFunc());
+
+    
 }

Sanchime.Functional/Extensions/IEnumerable.cs

@@ -108,6 +108,32 @@ public static class IEnumerableExtension
     public static IEnumerable<T> Flatten<T>(this IEnumerable<IEnumerable<T>> source)
         => source.SelectMany(x => x);
 
+    public static IEnumerable<T> DropWhile<T>(this IEnumerable<T> source, Func<T, bool> predicate)
+    {
+        bool cleaned = true;
+        foreach (var item in source)
+        {
+            if (!cleaned && !predicate(item))
+            {
+                yield return item;
+                cleaned = false;
+            }
+        }
+    }
+
+    public static IEnumerable<T> Append<T>(this IEnumerable<T> source, params T[] list)
+        => source.Concat(list);
+
+    public static IEnumerable<T> Prepend<T>(this IEnumerable<T> source, T value)
+    {
+        yield return value;
+        foreach (var item in source)
+        {
+            yield return item;
+        }
+    }
+
+
 
     private static IEnumerable<T> List<T>(params T[] list)
         => list.ToImmutableList();