Re: bug#5082: 23.1.50; print-circle and make-hash-table

Re: bug#5082: 23.1.50; print-circle and make-hash-table

[Ted Zlatanov]

The following message is a courtesy copy of an article
that has been posted to gnu.emacs.bug as well.

On Tue, 1 Dec 2009 00:09:30 +0900 川幡太一 <kawabata.taichi@gmail.com> wrote: 

> Dear Emacs Developers,
> I've found an Emacs behavior that seems a bug concerning to `print-circle'
> and make-hash-table, so I would like to report it.

> By setting `print-circle' to `t', printing Lisp Object with recursive
> or repetitive
> list should be displayed as #N= and #N# syntax.

> However, it seems this is not true when printing lisp objects within
> hash tables
> (which become possible in Emacs 23.1.50.)  Following is an example.

> Is it possible to display the repetitive lisp object within printed hash tables
> by #N= and #N# syntax, when `print-circle' is set to `t'?

> I notify this behavior as a bug, but it may not be so.  I apologize in that
> case.

> (let ((print-circle t)
>       (x (list 10 20))
>       (y (make-hash-table)))
>   (insert (format "%S\n" (list x x)))
>   (puthash 1 x y)
>   (puthash 2 x y)
>   (insert (format "%S\n" y))
>   (setcar x 3)
>   (insert (format "%S\n" y)))

> Result:
 (#1=(10 20) #1#)
 #s(hash-table size 65 test eql rehash-size 1.5 rehash-threshold 0.8
 data (1 (10 20) 2 (10 20)))
 #s(hash-table size 65 test eql rehash-size 1.5 rehash-threshold 0.8
 data (1 (3 20) 2 (3 20)))
> nil

I looked at the source in src/print.c.  At the print_object() level the
behavior is correct for lists but fiendishly complicated so I couldn't
figure out the parallel structure for hashtables quickly.  I'll put it
on my TODO list if no one else is interested.

Ted

Re: bug#5082: 23.1.50; print-circle and make-hash-table

[Glenn Morris]

Ted Zlatanov wrote:

> I'll put it on my TODO list if no one else is interested.

?

http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=5082#10

  From: Stefan Monnier <monnier at IRO.UMontreal.CA>
  Date: Mon, 30 Nov 2009 16:08:38 -0500

  I've installed the patch below which should fix it.

Re: bug#5082: 23.1.50; print-circle and make-hash-table

[Ted Zlatanov]

On Wed, 02 Dec 2009 22:12:18 -0500 Glenn Morris <rgm@gnu.org> wrote: 

GM> Ted Zlatanov wrote:
>> I'll put it on my TODO list if no one else is interested.

GM> ?

GM> http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=5082#10

GM>   From: Stefan Monnier <monnier at IRO.UMontreal.CA>
GM>   Date: Mon, 30 Nov 2009 16:08:38 -0500

GM>   I've installed the patch below which should fix it.

This is the second emacs bugs message I've missed in the last two weeks
(I also didn't see the URL auth bug resolution).  Something is up with
my news server (I read it via NNTP:gnu.emacs.bug).  Sorry for the noise.

Ted