Subject: Re: C++ briar patch (Was: Object IDs are bad)
From: (Rob Warnock)
Date: 1997/06/03
Newsgroups: comp.lang.scheme,comp.lang.lisp,comp.lang.misc,comp.lang.functional,comp.lang.c++
Message-ID: <5n0rst$>

Erik Naggum  <> wrote:
| it's worth noting that (cons 1 2) yields a pointer (!) to a cons cell that
| contains two fixnums, not two pointers.

Not in all Lisps. For example, in SIOD Scheme *all* objects are boxed,
thus a cons cell is two pointers, period.


p.s. Yes, there is a small amount of magic in the corners that avoids
allocating in the heap for the most common small numbers by preallocating
a few "inums" in fixed locations, and arranging so that arithmetic results
in that range share such an instance if it exists.

p.p.s. And yes, SIOD cons cells also have a type field. But that's not a
Lisp/Scheme requirement either, since you can always use BiBOP for typing.

Rob Warnock, 7L-551
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