[project @ 2002-02-13 15:07:59 by simonmar]

Don't translate out negative (boxed) literals too early.

diff --git a/ghc/compiler/parser/ParseUtil.lhs b/ghc/compiler/parser/ParseUtil.lhs
index ca546b8..04fd6df 100644 (file)
--- 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 (file)
--- 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