[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Arithmetic issues



On Tue, 18 Oct 2005, bear wrote:

The bitwise operations operate on exact integers only. Should they
live in the section on exact arithmetic? Should they carry ex
prefixes? Or should they be extended to work on inexact integers as
well?

I would say that having them operate on exact integers in the first
place is questionable; These are operations on bit vectors, not
operations on numbers, and their semantics require information (the
vector length) which is not expressed by the numbers.  To say that
they are defined on numbers is to confuse the number with a particular
representation.

I share the discomfort with the bitwise operations. As far as I can tell, the SRFI does not portably specify the value of (BITWISE-NOT 42).

Are these operations truly going to be useful for portable programs?
If not, one might reasonably ask what they will be doing in a portability standard such as R6RS.

Cheers
Andre