From 238491d9b5d35a1e5e44e5b34faade5f9b85effe Mon Sep 17 00:00:00 2001
From: Kei Hibino <ex8k.hibino@gmail.com>
Date: Thu, 30 Mar 2017 15:47:37 +0900
Subject: [PATCH] relational-query: add ShowConstantTermsSQL instances of tuple
 types.

---
 relational-query/src/Database/Relational/Query/Pure.hs      | 5 -----
 .../src/Database/Relational/Query/TupleInstances.hs         | 6 +++---
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/relational-query/src/Database/Relational/Query/Pure.hs b/relational-query/src/Database/Relational/Query/Pure.hs
index 9384c40a..4c1dfa60 100644
--- a/relational-query/src/Database/Relational/Query/Pure.hs
+++ b/relational-query/src/Database/Relational/Query/Pure.hs
@@ -158,8 +158,3 @@ showMaybeTerms wa = d  where
 instance (PersistableWidth a, ShowConstantTermsSQL a)
          => ShowConstantTermsSQL (Maybe a) where
   showConstantTermsSQL = showMaybeTerms persistableWidth
-
--- | Constant SQL terms of '(a, b)' type.
-instance (ShowConstantTermsSQL a, ShowConstantTermsSQL b)
-         => ShowConstantTermsSQL (a, b) where
-  showConstantTermsSQL (a, b) = showConstantTermsSQL a ++ showConstantTermsSQL b
diff --git a/relational-query/src/Database/Relational/Query/TupleInstances.hs b/relational-query/src/Database/Relational/Query/TupleInstances.hs
index 662662f3..23521bf8 100644
--- a/relational-query/src/Database/Relational/Query/TupleInstances.hs
+++ b/relational-query/src/Database/Relational/Query/TupleInstances.hs
@@ -18,11 +18,11 @@ module Database.Relational.Query.TupleInstances where
 
 import Control.Applicative ((<$>))
 
-import Database.Relational.Query.BaseTH (defineTuplePi, defineTupleProductConstructor)
+import Database.Relational.Query.BaseTH
+  (defineTuplePi, defineTupleProductConstructor, defineTupleShowConstantInstance,)
 
 
 $(concat <$> mapM defineTupleProductConstructor [2..7])
--- Generic instances of tuple types are generated from 2 to 7 in GHC.Generics.
-
 $(concat <$> mapM defineTuplePi [2..7])
+$(concat <$> mapM defineTupleShowConstantInstance [2..7])
 -- Generic instances of tuple types are generated from 2 to 7 in GHC.Generics.