Remove an old comment

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

diff --git a/GHC/Real.lhs b/GHC/Real.lhs
index da6053e..971f276 100644 (file)
--- a/GHC/Real.lhs
+++ b/GHC/Real.lhs
@@ -4,7 +4,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  GHC.Real
--- Copyright   :  (c) The FFI Task Force, 1994-2002
+-- Copyright   :  (c) The University of Glasgow, 1994-2002
 -- License     :  see libraries/base/LICENSE
 -- 
 -- Maintainer  :  cvs-ghc@haskell.org
@@ -24,6 +24,7 @@ import GHC.Num
 import GHC.List
 import GHC.Enum
 import GHC.Show
+import GHC.Err
 
 infixr 8  ^, ^^
 infixl 7  /, `quot`, `rem`, `div`, `mod`
@@ -132,10 +133,15 @@ class  (Real a, Enum a) => Integral a  where
     -- | conversion to 'Integer'
     toInteger           :: a -> Integer
 
+    {-# INLINE quot #-}
+    {-# INLINE rem #-}
+    {-# INLINE div #-}
+    {-# INLINE mod #-}
     n `quot` d          =  q  where (q,_) = quotRem n d
     n `rem` d           =  r  where (_,r) = quotRem n d
     n `div` d           =  q  where (q,_) = divMod n d
     n `mod` d           =  r  where (_,r) = divMod n d
+
     divMod n d          =  if signum r == negate (signum d) then (q-1, r+d) else qr
                            where qr@(q,r) = quotRem n d
 
@@ -153,6 +159,8 @@ class  (Num a) => Fractional a  where
     -- @('Fractional' a) => a@.
     fromRational        :: Rational -> a
 
+    {-# INLINE recip #-}
+    {-# INLINE (/) #-}
     recip x             =  1 / x
     x / y               = x * recip y
 
@@ -173,13 +181,15 @@ class  (Real a, Fractional a) => RealFrac a  where
     properFraction      :: (Integral b) => a -> (b,a)
     -- | @'truncate' x@ returns the integer nearest @x@ between zero and @x@
     truncate            :: (Integral b) => a -> b
-    -- | @'round' x@ returns the nearest integer to @x@
+    -- | @'round' x@ returns the nearest integer to @x@;
+    --   the even integer if @x@ is equidistant between two integers
     round               :: (Integral b) => a -> b
     -- | @'ceiling' x@ returns the least integer not less than @x@
     ceiling             :: (Integral b) => a -> b
     -- | @'floor' x@ returns the greatest integer not greater than @x@
     floor               :: (Integral b) => a -> b
 
+    {-# INLINE truncate #-}
     truncate x          =  m  where (m,_) = properFraction x
     
     round x             =  let (n,r) = properFraction x
@@ -447,19 +457,22 @@ lcm _ 0         =  0
 lcm 0 _         =  0
 lcm x y         =  abs ((x `quot` (gcd x y)) * y)
 
+#ifdef OPTIMISE_INTEGER_GCD_LCM
 {-# RULES
 "gcd/Int->Int->Int"             gcd = gcdInt
 "gcd/Integer->Integer->Integer" gcd = gcdInteger'
 "lcm/Integer->Integer->Integer" lcm = lcmInteger
  #-}
 
--- XXX to use another Integer implementation, you might need to disable
--- the gcd/Integer and lcm/Integer RULES above
---
 gcdInteger' :: Integer -> Integer -> Integer
 gcdInteger' 0 0 = error "GHC.Real.gcdInteger': gcd 0 0 is undefined"
 gcdInteger' a b = gcdInteger a b
 
+gcdInt :: Int -> Int -> Int
+gcdInt 0 0 = error "GHC.Real.gcdInt: gcd 0 0 is undefined"
+gcdInt a b = fromIntegral (gcdInteger (fromIntegral a) (fromIntegral b))
+#endif
+
 integralEnumFrom :: (Integral a, Bounded a) => a -> [a]
 integralEnumFrom n = map fromInteger [toInteger n .. toInteger (maxBound `asTypeOf` n)]