From 0e95ca1da48808f840b3f3088eb259f07d8e8fcc Mon Sep 17 00:00:00 2001
From: RyanGlScott <ryan.gl.scott@ku.edu>
Date: Thu, 16 Jul 2015 13:00:00 -0500
Subject: [PATCH] Backport PrintfArg Natural instance to GHC 7.8

---
 src/Numeric/Natural.hs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/Numeric/Natural.hs b/src/Numeric/Natural.hs
index cbc1e0b..5ca64bd 100644
--- a/src/Numeric/Natural.hs
+++ b/src/Numeric/Natural.hs
@@ -43,6 +43,9 @@ import Data.Data
 #ifdef MIN_VERSION_hashable
 import Data.Hashable
 #endif
+#if MIN_VERSION_base(4,7,0) && !(MIN_VERSION_base(4,8,0))
+import Text.Printf (PrintfArg(..), formatInteger)
+#endif
 
 -- | Type representing arbitrary-precision non-negative integers.
 --
@@ -206,3 +209,9 @@ instance Integral Natural where
   {-# INLINE quotRem #-}
   toInteger = runNatural
   {-# INLINE toInteger #-}
+
+#if MIN_VERSION_base(4,7,0) && !(MIN_VERSION_base(4,8,0))
+instance PrintfArg Natural where
+  formatArg     = formatInteger . toInteger
+  parseFormat _ = parseFormat (undefined :: Integer)
+#endif