X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Data%2FRatio.hs;h=f0440993a38a0bdd1452c1eb6698bb3027e8371b;hb=HEAD;hp=22f3abeeeff8661ee1dc5a620db4d98e9abc1fff;hpb=96327b0696bc28551fbdb303506c52b9ee70c95c;p=ghc-base.git

diff --git a/Data/Ratio.hs b/Data/Ratio.hs
index 22f3abe..f044099 100644
--- a/Data/Ratio.hs
+++ b/Data/Ratio.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Ratio
@@ -15,10 +17,10 @@
 module Data.Ratio
     ( Ratio
     , Rational
-    , (%)		-- :: (Integral a) => a -> a -> Ratio a
-    , numerator		-- :: (Integral a) => Ratio a -> a
-    , denominator	-- :: (Integral a) => Ratio a -> a
-    , approxRational	-- :: (RealFrac a) => a -> a -> Rational
+    , (%)               -- :: (Integral a) => a -> a -> Ratio a
+    , numerator         -- :: (Integral a) => Ratio a -> a
+    , denominator       -- :: (Integral a) => Ratio a -> a
+    , approxRational    -- :: (RealFrac a) => a -> a -> Rational
 
     -- Ratio instances: 
     --   (Integral a) => Eq   (Ratio a)
@@ -27,16 +29,16 @@ module Data.Ratio
     --   (Integral a) => Real (Ratio a)
     --   (Integral a) => Fractional (Ratio a)
     --   (Integral a) => RealFrac (Ratio a)
-    --   (Integral a) => Enum	  (Ratio a)
+    --   (Integral a) => Enum     (Ratio a)
     --   (Read a, Integral a) => Read (Ratio a)
-    --   (Integral a) => Show	  (Ratio a)
+    --   (Integral a) => Show     (Ratio a)
 
   ) where
 
 import Prelude
 
 #ifdef __GLASGOW_HASKELL__
-import GHC.Real		-- The basic defns for Ratio
+import GHC.Real         -- The basic defns for Ratio
 #endif
 
 #ifdef __HUGS__
@@ -68,27 +70,27 @@ import Ratio (Ratio(..), (%), numerator, denominator, approxRational)
 -- and abs r' < d', and the simplest rational is q%1 + the reciprocal of
 -- the simplest rational between d'%r' and d%r.
 
-approxRational		:: (RealFrac a) => a -> a -> Rational
-approxRational rat eps	=  simplest (rat-eps) (rat+eps)
-	where simplest x y | y < x	=  simplest y x
-			   | x == y	=  xr
-			   | x > 0	=  simplest' n d n' d'
-			   | y < 0	=  - simplest' (-n') d' (-n) d
-			   | otherwise	=  0 :% 1
-					where xr  = toRational x
-					      n   = numerator xr
-					      d   = denominator xr
-					      nd' = toRational y
-					      n'  = numerator nd'
-					      d'  = denominator nd'
+approxRational          :: (RealFrac a) => a -> a -> Rational
+approxRational rat eps  =  simplest (rat-eps) (rat+eps)
+        where simplest x y | y < x      =  simplest y x
+                           | x == y     =  xr
+                           | x > 0      =  simplest' n d n' d'
+                           | y < 0      =  - simplest' (-n') d' (-n) d
+                           | otherwise  =  0 :% 1
+                                        where xr  = toRational x
+                                              n   = numerator xr
+                                              d   = denominator xr
+                                              nd' = toRational y
+                                              n'  = numerator nd'
+                                              d'  = denominator nd'
 
-	      simplest' n d n' d'	-- assumes 0 < n%d < n'%d'
-			| r == 0     =	q :% 1
-			| q /= q'    =	(q+1) :% 1
-			| otherwise  =	(q*n''+d'') :% n''
-				     where (q,r)      =	 quotRem n d
-					   (q',r')    =	 quotRem n' d'
-					   nd''       =  simplest' d' r' d r
-					   n''        =  numerator nd''
-					   d''        =	 denominator nd''
+              simplest' n d n' d'       -- assumes 0 < n%d < n'%d'
+                        | r == 0     =  q :% 1
+                        | q /= q'    =  (q+1) :% 1
+                        | otherwise  =  (q*n''+d'') :% n''
+                                     where (q,r)      =  quotRem n d
+                                           (q',r')    =  quotRem n' d'
+                                           nd''       =  simplest' d' r' d r
+                                           n''        =  numerator nd''
+                                           d''        =  denominator nd''
 #endif