From e3cf683e71cce9cc243be3ec81f729c6d4f4982a Mon Sep 17 00:00:00 2001
From: ross <unknown>
Date: Thu, 26 Feb 2004 18:34:14 +0000
Subject: [PATCH] [project @ 2004-02-26 18:34:14 by ross] instances for
 Ordering and tuples (up to 5)

---
 Data/Monoid.hs |   30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/Data/Monoid.hs b/Data/Monoid.hs
index a328639..c3e3ff7 100644
--- a/Data/Monoid.hs
+++ b/Data/Monoid.hs
@@ -58,3 +58,33 @@ instance Monoid () where
 	mempty        = ()
 	_ `mappend` _ = ()
 	mconcat _     = ()
+
+instance (Monoid a, Monoid b) => Monoid (a,b) where
+	mempty = (mempty, mempty)
+	(a1,b1) `mappend` (a2,b2) =
+		(a1 `mappend` a2, b1 `mappend` b2)
+
+instance (Monoid a, Monoid b, Monoid c) => Monoid (a,b,c) where
+	mempty = (mempty, mempty, mempty)
+	(a1,b1,c1) `mappend` (a2,b2,c2) =
+		(a1 `mappend` a2, b1 `mappend` b2, c1 `mappend` c2)
+
+instance (Monoid a, Monoid b, Monoid c, Monoid d) => Monoid (a,b,c,d) where
+	mempty = (mempty, mempty, mempty, mempty)
+	(a1,b1,c1,d1) `mappend` (a2,b2,c2,d2) =
+		(a1 `mappend` a2, b1 `mappend` b2,
+		 c1 `mappend` c2, d1 `mappend` d2)
+
+instance (Monoid a, Monoid b, Monoid c, Monoid d, Monoid e) =>
+		Monoid (a,b,c,d,e) where
+	mempty = (mempty, mempty, mempty, mempty, mempty)
+	(a1,b1,c1,d1,e1) `mappend` (a2,b2,c2,d2,e2) =
+		(a1 `mappend` a2, b1 `mappend` b2, c1 `mappend` c2,
+		 d1 `mappend` d2, e1 `mappend` e2)
+
+-- lexicographical ordering
+instance Monoid Ordering where
+	mempty         = EQ
+	LT `mappend` _ = LT
+	EQ `mappend` y = y
+	GT `mappend` _ = GT
-- 
1.7.10.4