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Re: Bug in documentation for eq? ?

From: David Kastrup
Subject: Re: Bug in documentation for eq? ?
Date: Wed, 20 Jun 2012 17:16:06 +0200
User-agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1.50 (gnu/linux)

Andy Wingo <address@hidden> writes:

> On Wed 20 Jun 2012 16:27, David Kastrup <address@hidden> writes:
>> I am not comparing numbers when writing (eq? x x).
>> I am checking the identity of an object.  Whether that object is a
>> number or not, and if so, what value it has, is irrelevant.
> "x" is not an object: it is a variable.  Variables do not have identity.

Variables have values.  Values are scheme objects.  Scheme objects have
identity.  Numbers of identical numeric value may or may not be mapped
to identical scheme objects.  But identical scheme objects may not
choose to become unidentical.  Something like

(while (and (list? x) (pair? x))
  (set! x (delq (car x) x)))

should be guaranteed to terminate in any sane implementation, even if
the list contains numbers.

Whatever.  It is quite clear that you can't be bothered with caring
about sane semantics when the standard gives you a free pass.

Forget I asked.  I don't see the point in further serving as a target
for pseudointellectual mockery.

David Kastrup

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