From: simonpj@microsoft.com <unknown>
Date: Thu, 29 Oct 2009 13:44:14 +0000 (+0000)
Subject: Tidy up and comment imports
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=a009c4b45817286eda2cd95259c7e7adfe69a75c;hp=ff3d1aecef407d6a1eee09f92684a96d64e27c10;p=ghc-base.git

Tidy up and comment imports
---

diff --git a/Data/Tuple.hs b/Data/Tuple.hs
index 5c752a8..22b9f78 100644
--- a/Data/Tuple.hs
+++ b/Data/Tuple.hs
@@ -41,15 +41,19 @@ module Data.Tuple
     where
 
 #ifdef __GLASGOW_HASKELL__
-import GHC.Bool
-import GHC.Classes
-import GHC.Ordering
--- XXX The standalone deriving clauses fail with
---     The data constructors of `(,)' are not all in scope
---       so you cannot derive an instance for it
---     In the stand-alone deriving instance for `Eq (a, b)'
--- if we don't import GHC.Tuple
+
+import GHC.Base
+-- We need to depend on GHC.Base so that
+-- a) so that we get GHC.Bool, GHC.Classes, GHC.Ordering
+
+-- b) so that GHC.Base.inline is available, which is used
+--    when expanding instance declarations
+
 import GHC.Tuple
+-- We must import GHC.Tuple, to ensure sure that the 
+-- data constructors of `(,)' are in scope when we do
+-- the standalone deriving instance for Eq (a,b) etc
+
 #endif  /* __GLASGOW_HASKELL__ */
 
 #ifdef __NHC__