[commit: ghc] wip/occname: Wiring in tuples note (e13f37a)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : wip/occname
Link       : http://ghc.haskell.org/trac/ghc/changeset/e13f37aef116eca7cb0548abbf7b8fdce7650c79/ghc

>---------------------------------------------------------------

commit e13f37aef116eca7cb0548abbf7b8fdce7650c79
Author: Ben Gamari <ben at smart-cactus.org>
Date:   Tue Jul 12 00:12:52 2016 +0200

    Wiring in tuples note
    
    This should probably just be folded in to the note above


>---------------------------------------------------------------

e13f37aef116eca7cb0548abbf7b8fdce7650c79
 compiler/iface/IfaceEnv.hs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/compiler/iface/IfaceEnv.hs b/compiler/iface/IfaceEnv.hs
index b70c8e9..d4aa03b 100644
--- a/compiler/iface/IfaceEnv.hs
+++ b/compiler/iface/IfaceEnv.hs
@@ -202,6 +202,16 @@ However, there are two reasons why we might look up an Orig RdrName:
     go this route (Trac #8954).
 -}
 
+{-
+Note [Wiring in tuples]
+~~~~~~~~~~~~~~~~~~~~~~~
+
+The wiring-in of the tuple types is a bit tricky. The reason is that there are
+very many of them and we consequently want to avoid cluttering the name cache
+with them unnecessarily. For this reason we specially encode tuple Names in
+interface files,
+-}
+
 lookupOrigNameCache :: OrigNameCache -> Module -> OccName -> Maybe Name
 lookupOrigNameCache nc mod occ
   | mod == gHC_TYPES