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

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:

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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