[Haskell] for large x, log (x::Integer) :: Double

[Dylan Thurston]

On Mon, Jul 12, 2004 at 04:29:22PM +0200, Ronny Wichers Schreur wrote:
> Edmund GRIMLEY EVANS asks (to the Haskell mailing list):
> 
> >Does Haskell provide any means of determining the number of
> >binary digits in an Integer other than by repeated division?
> 
> Dylan Thurston answers:
> 
> >See the Data.Bits library:
> >
> >http://www.haskell.org/ghc/docs/latest/html/libraries/base/Data.Bits.html
> 
> This library will let you use a shift instead of a division,
> but won't give you a constant time size function for Integers.

You can easily get a logarithmic time size function from the shift.
But did you see Data.Bits.bitsize?

Peace,
	Dylan
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