re: Issue: FIXNUM-NON-PORTABLE (Version 4)

[Kim A. Barrett <IIM@ECLA.USC.EDU>]

NO on both.

Basically, I don't think either proposal really addresses the problem
adequately.  I'm looking at this from the point of view of someone who has
dealt with porting C programs between machines with different native word
sizes, and therefor different definitions of the 'int' type.  I see many of the
same kinds of problems here, and the approach being taken by these proposals
really doesn't do anything about them.

Actually, I think a case could be made in favor of a third proposal,
TOSS-FIXNUM-TOSS-BIGNUM, making it explicit that neither is portable.  I'm not
planning to put this forward as a serious proposal though, since I expect it
would go over like a lead balloon for historical reasons if nothing else.
There are relatively few legitimate uses of FIXNUM in portable code, and
legislating the definition of FIXNUM in a fairly ad hoc way is not going to
improve the situation.  About the only place the FIXNUM type specifier should
appear in portable code is as part of the definition of a type used by the
portable code, with the definition parameterized according to the
implementation being ported to.  Even there it is probably better to use ranged
integer type specifiers.