[project @ 2002-08-25 09:16:07 by panne]

[ghc-base.git] / GHC / Real.lhs

diff --git a/GHC/Real.lhs b/GHC/Real.lhs
index be30073..e1696cc 100644 (file)
--- a/GHC/Real.lhs
+++ b/GHC/Real.lhs
@@ -40,8 +40,16 @@ default ()           -- Double isn't available yet,
 
 \begin{code}
 data  (Integral a)     => Ratio a = !a :% !a  deriving (Eq)
+
+-- | Arbitrary-precision rational numbers, represented as a ratio of
+-- two 'Integer' values.  A rational number may be constructed using
+-- the '%' operator.
 type  Rational         =  Ratio Integer
 
+ratioPrec, ratioPrec1 :: Int
+ratioPrec  = 7         -- Precedence of ':%' constructor
+ratioPrec1 = ratioPrec + 1
+
 infinity, notANumber :: Rational
 infinity   = 1 :% 0
 notANumber = 0 :% 0
@@ -242,11 +250,10 @@ instance  (Integral a)    => RealFrac (Ratio a)  where
 
 instance  (Integral a)  => Show (Ratio a)  where
     {-# SPECIALIZE instance Show Rational #-}
-    showsPrec p (x:%y) =  showParen (p > ratio_prec)
-                              (shows x . showString " % " . shows y)
-
-ratio_prec :: Int
-ratio_prec = 7
+    showsPrec p (x:%y) =  showParen (p > ratioPrec) $
+                          showsPrec ratioPrec1 x . 
+                          showString " % " . 
+                          showsPrec ratioPrec1 y
 
 instance  (Integral a) => Enum (Ratio a)  where
     {-# SPECIALIZE instance Enum Rational #-}