Dan Piponi wrote:
Is there anything in any of the interfaces to Integer that will allow me to quickly find the highest bit set in an Integer? If not, does anyone have any recommendations for how to do it efficiently. There are some obvious things that come to mind but which might involve quite a bit of useless copying of data internally by the implementation of Integer. -- Dan The subject line and your description disagree by 1 bit. Take the number 7: its binary representation would be 0111, with 0100 being the highest bit, whereas the smallest power of 2 >= 7 is 8, or 1000 in binary. And how do you want the results? The place value of that highest bit? Or its index?
For the index, how about this: truncate . (/(log 2)) . log . fromIntegral for the place value, just add an exponent function and another cast: (2**) . fromIntegral . truncate . (/(log 2)) . log . fromIntegral If you want the smallest power of 2 >= the integer, just change truncate to ceiling.