shithub: MicroHs

Info  •  Files  •  Log  •  Branches

Implement properFraction

--- a/lib/Data/FloatW.hs

+++ b/lib/Data/FloatW.hs

@@ -12,6 +12,7 @@

 import Data.Fractional

 import Data.Function

 import Data.Integer

+import Data.Integral

 import Data.List

 import Data.Ord

 import Data.Ratio

@@ -77,7 +78,12 @@

       (m, e) -> toRational m * 2^^e

 instance RealFrac FloatW where

-  properFraction _ = error "FloatW.properFraction not implemented"

+  properFraction x =

+    case decodeFloat x of

+      (m, e) ->   -- x = m * 2^e

+        let m' | e < 0     = m `quot` 2^(-e)

+               | otherwise = m * 2^e

+        in  (fromInteger m', x - fromInteger m')

 instance Floating FloatW where

   pi     = 3.141592653589793