From d113ae78f633ea5b12a24e4fcb7693d961869d3e Mon Sep 17 00:00:00 2001
From: simonmar <unknown>
Date: Wed, 13 Feb 2002 15:08:00 +0000
Subject: [PATCH] [project @ 2002-02-13 15:07:59 by simonmar] Don't translate
 out negative (boxed) literals too early.

---
 ghc/compiler/parser/ParseUtil.lhs |    8 ++++++++
 ghc/compiler/parser/RdrHsSyn.lhs  |   12 +-----------
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/ghc/compiler/parser/ParseUtil.lhs b/ghc/compiler/parser/ParseUtil.lhs
index ca546b8..04fd6df 100644
--- a/ghc/compiler/parser/ParseUtil.lhs
+++ b/ghc/compiler/parser/ParseUtil.lhs
@@ -198,6 +198,14 @@ checkPat e [] = case e of
 			      in
 			      returnP (SigPatIn e t')
 
+	-- translate out NegApps of literals in patterns.
+	-- NB. negative primitive literals are already handled by
+	-- RdrHsSyn.mkHsNegApp
+	NegApp (HsOverLit (HsIntegral i n)) _
+		-> returnP (NPatIn (HsIntegral (-i) n))
+	NegApp (HsOverLit (HsFractional f n)) _
+		-> returnP (NPatIn (HsFractional (-f) n))
+
 	OpApp (HsVar n) (HsVar plus) _ (HsOverLit lit@(HsIntegral _ _)) 
 		  	   | plus == plus_RDR
 			   -> returnP (mkNPlusKPat n lit)
diff --git a/ghc/compiler/parser/RdrHsSyn.lhs b/ghc/compiler/parser/RdrHsSyn.lhs
index c482844..6626fce 100644
--- a/ghc/compiler/parser/RdrHsSyn.lhs
+++ b/ghc/compiler/parser/RdrHsSyn.lhs
@@ -237,21 +237,11 @@ mkHsNegApp :: RdrNameHsExpr -> RdrNameHsExpr
 -- If the type checker sees (negate 3#) it will barf, because negate
 -- can't take an unboxed arg.  But that is exactly what it will see when
 -- we write "-3#".  So we have to do the negation right now!
--- 
--- We also do the same service for boxed literals, because this function
--- is also used for patterns (which, remember, are parsed as expressions)
--- and pattern don't have negation in them.
--- 
--- Finally, it's important to represent minBound as minBound, and not
--- as (negate (-minBound)), becuase the latter is out of range. 
 
 mkHsNegApp (HsLit (HsIntPrim i))    = HsLit (HsIntPrim (-i))    
 mkHsNegApp (HsLit (HsFloatPrim i))  = HsLit (HsFloatPrim (-i))  
 mkHsNegApp (HsLit (HsDoublePrim i)) = HsLit (HsDoublePrim (-i)) 
-
-mkHsNegApp (HsOverLit (HsIntegral   i n)) = HsOverLit (HsIntegral   (-i) n)
-mkHsNegApp (HsOverLit (HsFractional f n)) = HsOverLit (HsFractional (-f) n)
-mkHsNegApp expr 		  	  = NegApp expr negateName
+mkHsNegApp expr		  	    = NegApp expr negateName
 \end{code}
 
 A useful function for building @OpApps@.  The operator is always a
-- 
1.7.10.4