From 0e73a9fbdc8555ffb948cfd72401a700b122c395 Mon Sep 17 00:00:00 2001
From: "simonpj@microsoft.com" <unknown>
Date: Wed, 16 Dec 2009 08:45:13 +0000
Subject: [PATCH] Fix a long-standing infelicity in the type pretty printer

We weren't parenthesising
   List (C Int)
correctly, when (C Int) is a PredTy
---
 compiler/types/TypeRep.lhs |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/compiler/types/TypeRep.lhs b/compiler/types/TypeRep.lhs
index a5176ce..1660267 100644
--- a/compiler/types/TypeRep.lhs
+++ b/compiler/types/TypeRep.lhs
@@ -471,7 +471,8 @@ ppr_type :: Prec -> Type -> SDoc
 ppr_type _ (TyVarTy tv)		-- Note [Infix type variables]
   | isSymOcc (getOccName tv)  = parens (ppr tv)
   | otherwise		      = ppr tv
-ppr_type _ (PredTy pred)      = ifPprDebug (ptext (sLit "<pred>")) <> (ppr pred)
+ppr_type p (PredTy pred)      = maybeParen p TyConPrec $
+                                ifPprDebug (ptext (sLit "<pred>")) <> (ppr pred)
 ppr_type p (TyConApp tc tys)  = ppr_tc_app p tc tys
 
 ppr_type p (AppTy t1 t2) = maybeParen p TyConPrec $
-- 
1.7.10.4