[commit: base] master: Make "100e12" not parse as an Integer; part of #5688 (bed3d79)

[Ian Lynagh]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/base

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/bed3d7937bea1619f7cf05af8babd8dd4385f348

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

commit bed3d7937bea1619f7cf05af8babd8dd4385f348
Author: Ian Lynagh <igloo at earth.li>
Date:   Thu Mar 1 14:05:36 2012 +0000

    Make "100e12" not parse as an Integer; part of #5688
    
    The report says that it isn't meant to.

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

 Text/Read/Lex.hs |    7 +------
 1 files changed, 1 insertions(+), 6 deletions(-)

diff --git a/Text/Read/Lex.hs b/Text/Read/Lex.hs
index ac6ec68..7ae8e9f 100644
--- a/Text/Read/Lex.hs
+++ b/Text/Read/Lex.hs
@@ -79,12 +79,7 @@ data Number = MkNumber Int              -- Base
 
 numberToInteger :: Number -> Maybe Integer
 numberToInteger (MkNumber base iPart) = Just (val (fromIntegral base) 0 iPart)
-numberToInteger (MkDecimal iPart Nothing mExp)
-    = let i = val 10 0 iPart
-      in case mExp of
-         Nothing             -> Just i
-         Just exp | exp >= 0 -> Just (i * (10 ^ exp))
-         _                   -> Nothing
+numberToInteger (MkDecimal iPart Nothing Nothing) = Just (val 10 0 iPart)
 numberToInteger _ = Nothing
 
 numberToRational :: Number -> Rational