GNU bug report logs - #18223
[PATCH] Fix thinko concerning object property docs

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From: Nala Ginrut <nalaginrut <at> gmail.com>
To: David Kastrup <dak <at> gnu.org>
Cc: 18223 <at> debbugs.gnu.org
Subject: bug#18223: Duplicate of issue 14792
Date: Sat, 9 Aug 2014 20:16:15 +0800

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I can't reproduce it, but I'm using the latest mater. Could you provide
your version?
 2014年8月9日 下午5:47于 "David Kastrup" <dak <at> gnu.org>写道：

>
> This is actually a duplicate of issue 14792 which has been ignored for
> over a year by now.
>
> Please see <URL:http://debbugs.gnu.org/cgi/bugreport.cgi?bug=14792#35>
> for the reason the provided patch (namely discouraging the use of
> numbers for object properties) is the only one making sense.
>
> Here is the rationale in code: object properties are implemented via
> key-weak hash tables, and weak hash tables will not work with eqv? as
> equivalence since key-weakness is related to garbage collection which
> cannot consider anything but eq?-equivalence.
>
> scheme@(guile-user)> (define x (make-weak-key-hash-table))
> scheme@(guile-user)> (hashv-set! x 100000000000000000000 #t)
> $6 = #t
> scheme@(guile-user)> (gc)
> scheme@(guile-user)> (hashv-ref x 100000000000000000000)
> $7 = #f
>
> Guile and/or Scheme do not store the equivalence relation in the
> hashtable itself, and user-definable hash functions may establish
> arbitrary relations regarding key uniqueness that have no clear relation
> to the object identity used by garbage collection.
>
> --
> David Kastrup
>
>
>
>

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