[Scheme-reports] Problems with the 9th ballot Mark H Weaver (26 Nov 2012 16:31 UTC)
Re: [Scheme-reports] Problems with the 9th ballot John Cowan (26 Nov 2012 16:52 UTC)

[Scheme-reports] Problems with the 9th ballot Mark H Weaver 26 Nov 2012 16:26 UTC

The 9th ballot was clearly written by the (only) member of the working
group who wants 'eqv?' to be defined in terms of '='.  Ballots should
present the options fairly, and not be abused to present a
heavily-biased summary of the issues from a minority perspective.

The ballot states: <http://trac.sacrideo.us/wg/wiki/WG1Ballot>

   Ultra-brief history:

   R2RS was purely mathematical, defining 'eqv?' on numbers in terms of
   '='.  R3RS defined a simple operational equivalence by distinguishing
   exact and inexact.

This history is a crock.

Both the RRRS and R3RS make it crystal clear in their primary
definitions of 'eqv?' that it is based on operational equivalence, and
they both provide the explicit guarantee that 'eqv?' will return #f if
the objects are distinguishable.

The R3RS makes it clear that the suggested rule for numeric
representations at the time (involving = and exactness) is merely an
"interpretation" of the definition of "operational equivalence".

I'd invite everyone to read those reports' definitions of 'eqv?' to see
for yourself:

RRRS: <http://dspace.mit.edu/bitstream/handle/1721.1/5600/AIM-848.pdf>
(page 24)

R3RS: <http://people.csail.mit.edu/jaffer/r3rs_8.html>

For another history, see http://trac.sacrideo.us/wg/ticket/477

     Mark

_______________________________________________
Scheme-reports mailing list
Scheme-reports@scheme-reports.org
http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports