Proposal: Better power for Rational
schlepptop at henning-thielemann.de
Tue Sep 28 14:23:01 EDT 2010
Simon Peyton-Jones schrieb:
> | > #4101: constant folding for (**)
> | > #3676: realToFrac conversions
> | > #3744: comparisons against minBound and maxBound are not optimised away
> | > #3065: quot is sub-optimal
> | > #2269: Word type to Double or Float conversions
> | > #2271: floor, ceiling, round :: Double -> Int are awesomely slow
> | > #1434: slow conversion Double to Int
> | For the rounding issue I have already written some code for numeric-prelude:
> | http://code.haskell.org/numeric-prelude/src/Algebra/RealRing.hs
> Great. I'm not sure which ticket you are referring to, but if you could propose a patch, by email to the libraries list, that would be great
I'm referring to tickets #2271 and #1434.
I implemented round, truncate, floor, ceiling with Int result in terms
of double2Int and friends and added RULES for decomposing, e.g.
round :: Double -> Int16
(fromIntegral :: Int -> Int16) . (round :: Double -> Int)
However my code is adapted to NumericPrelude's type classes and must be
adapted to those of Haskell98's Prelude. This should not be too hard.
I'll try to create a patch, however I may need some assistance compiling
More information about the Libraries