Lars Brinkhoff <lars.spam@nocrew.org> wrote:
+
 rpw3@rpw3.org (Rob Warnock) writes:
 > Sidney Markowitz <sidney@sidney.com> wrote:
 > > Johan Bockgård wrote:
 > > > Actually, [in Emacs Lisp?] (/ 3 5) ==> 0
 > > CLtL 12.4 Arithmetic Operations / will produce a ratio if the
 > > mathematical quotient of two integers is not an exact integer.
 > Exactly. Which breaks the "equivalent semantics" rule of CLHS 1.7.
 > [So it's going to be hard to use Emac Lisp as the implementation
 > substrate of a conforming "CL subset".]

 I don't understand that. I have used Emacs Lisp as the implementation
 substrate of a (purportedly) conforming CL subset, and I didn't find
 the differences between / in Emacs Lisp and Common Lisp to be a hard
 problem. It's probably on par with using, say, C as a substrate,
 which is common enough.
+
So you're saying you implemented rationals in your CL subset?
O.k., then no problem, any more than doing it in C [with all
that that implies!] is a "problem". But in that case you didn't
use Emac's own arithmetic *as* the arithmetic for the subset,
which is what I addressing.
And my apologies if I misunderstood the context of your previous
remarks...
+
 You wouldn't be say that C is an inappropriate *implementation*
 language just because its operators doesn't have a subset of CL
 semantics, would you? Of course, C isn't a CL subset. :)
+
So is it your opinion that Emacs Lisp is a reasonable  or at least,
substantially easier/better than C  implementation substrate for
a conforming CL subset? If so, that's a interesting & potentially
very useful datapoint, since AFAIK Emacs can iteself be compiled
directly from C.
Rob

Rob Warnock <rpw3@rpw3.org>
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