| From: Alan Watson <[email protected]> | Date: Thu, 29 Mar 2012 12:25:41 -0600 | | > See <http://srfi.schemers.org/srfi-60/srfi-60.html>. Bitwise | > operations on integers (both positive and negative) are well defined | > and implementable in pure R4RS using no more bits than the input | > numbers. | | The implementation of SRFI-60 assumes two's complement binary representations: | | (define (lognot n) (- -1 n))
SRFI-60 implements 2's complement. LOGNOT returns the same integer whether running on 1's complement, 2's complement, sign-magnitude, or BCD hardware (although it may require one more digit than its argument). | However, in this context, the basic point that you can implement a | mapping from any finite domain in R4RS Scheme using a look-up table | remains valid. | | Regards, | | Alan _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
