On Friday 22 October 2010 02:50:41, Isaac Dupree wrote:
On 10/21/10 15:35, Daniel Fischer wrote:
trac: http://hackage.haskell.org/trac/ghc/ticket/4344#comment:10
Proposal: include faster implementations for
1. toRational :: Float -> Rational 2. toRational :: Double -> Rational 3. fromRational :: Rational -> Float 4. fromRational :: Rational -> Double
The semantics of these functions shall remain the same as it is now, only their speed will be affected.
I generally approve! If the libraries list has any non-trivial doubts then it might be best not to squeeze it into 7.0. But if not, then great!(IMHO)
Do we, the Libraries list, need to approve adding ( integerLog2# :: Integer -> Int# ) to the integer-* packages? I had the notion those are relatively private packages that GHC developers have purview over.
Well, I don't know. I'm not quite clear on which libraries concern libraries@ and which not, so I rather ask too often than too rarely (and then get told "No, can't do that").
(Then we could think separately from this proposal about adding a user-friendly integerLog2 to somewhere nice; and then I'd wish for a log2 for types like Int as well; maybe it would make sense for Data.Bits; questions like that. I would be supportive but I don't think we have to do this before we optimize Rational.)
I have also wordLog2# :: Word# -> Int#, that would cover also Int arguments (and WordN, IntN for N <= WORD_SIZE_IN_BITS, but the smaller types would profit from special implementations as the high bits are checked first; those would be easy to add).
-Isaac