X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Data%2FComplex.hs;h=bbc8a07db2449f75bf26c1d70c9eb6eef4b74cb2;hb=4d9023e9281493aea632196980543dfdedfd9910;hp=3acfa0382f18343ac996ef77aeff289dd80696b1;hpb=5ba151f462d0ec7ee9241b3c259979d51777f39b;p=ghc-base.git

diff --git a/Data/Complex.hs b/Data/Complex.hs
index 3acfa03..bbc8a07 100644
--- a/Data/Complex.hs
+++ b/Data/Complex.hs
@@ -44,6 +44,9 @@ module Data.Complex
 import Prelude
 
 import Data.Typeable
+#ifdef __GLASGOW_HASKELL__
+import Data.Data (Data)
+#endif
 
 #ifdef __HUGS__
 import Hugs.Prelude(Num(fromInt), Fractional(fromDouble))
@@ -62,7 +65,11 @@ infix  6  :+
 data (RealFloat a) => Complex a
   = !a :+ !a    -- ^ forms a complex number from its real and imaginary
                 -- rectangular components.
+# if __GLASGOW_HASKELL__
+        deriving (Eq, Show, Read, Data)
+# else
         deriving (Eq, Show, Read)
+# endif
 
 -- -----------------------------------------------------------------------------
 -- Functions over Complex
@@ -103,9 +110,10 @@ polar z          =  (magnitude z, phase z)
 {-# SPECIALISE magnitude :: Complex Double -> Double #-}
 magnitude :: (RealFloat a) => Complex a -> a
 magnitude (x:+y) =  scaleFloat k
-                     (sqrt ((scaleFloat mk x)^(2::Int) + (scaleFloat mk y)^(2::Int)))
+                     (sqrt (sqr (scaleFloat mk x) + sqr (scaleFloat mk y)))
                     where k  = max (exponent x) (exponent y)
                           mk = - k
+                          sqr z = z * z
 
 -- | The phase of a complex number, in the range @(-'pi', 'pi']@.
 -- If the magnitude is zero, then so is the phase.