realToFrac vs. fromRealFrac
Manuel M. T. Chakravarty
chak@cse.unsw.edu.au
Sat, 03 Feb 2001 23:34:37 +1100
I am not sure whether the following issue has already been
mentioned earlier.
Chapter 6 ``Predefined Types and Classes'' of The Report
says at its very end,
Also available are the following coercion functions:
fromIntegral :: (Integral a, Num b) => a -> b
fromRealFrac :: (RealFrac a, Fractional b) => a -> b
(`fromRealFrac' is also defined in Figure 7.)
However, in Appendix A ``Standard Prelude'', we have
realToFrac :: (Real a, Fractional b) => a -> b
realToFrac = fromRational . toRational
instead of a definition for `fromRealFrac'.
Both GHC and Hugs go by Appendix A. What was the original
intention?
Cheers,
Manuel