From c4231e1423e5c81f2779acf4462eea8872f6a4e6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9s=20Sicard-Ram=C3=ADrez?= <asr@eafit.edu.co>
Date: Sun, 7 Jan 2018 23:52:32 -0500
Subject: [PATCH] Added Semigroup instance.

The instance was required by GHC 8.4.1-alpha1.
---
 src/Control/Monad/Plus.hs | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/Control/Monad/Plus.hs b/src/Control/Monad/Plus.hs
index 25f4782..a4af848 100644
--- a/src/Control/Monad/Plus.hs
+++ b/src/Control/Monad/Plus.hs
@@ -1,5 +1,5 @@
 
-{-# LANGUAGE DeriveFunctor, DeriveFoldable, GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE CPP, DeriveFunctor, DeriveFoldable, GeneralizedNewtypeDeriving #-}
 
 -------------------------------------------------------------------------------------
 -- |
@@ -261,8 +261,13 @@ instance Category Partial where
         y <- g x
         f y
 
+#if MIN_VERSION_base(4,11,0)
+instance Semigroup (Partial a b) where
+  (<>) = mplus
+#endif
+
 instance Monoid (Partial a b) where
     mempty  = mzero
+#if !MIN_VERSION_base(4,11,0)
     mappend = mplus
-
-
+#endif