* bug#7083: Why is `copy-tree's symbol-plist carrying side-effect-free error-free?
@ 2010-09-22 6:31 MON KEY
2010-09-22 21:35 ` Andreas Schwab
0 siblings, 1 reply; 4+ messages in thread
From: MON KEY @ 2010-09-22 6:31 UTC (permalink / raw)
To: 7083
Why is `copy-tree' side-effect-free error-free?
(symbol-plist 'copy-tree)
=> (side-effect-free error-free)
It (potentially) `nconc's `nreverse's and `aset's the TREE arg recursively.
At revno: 45675 `copy-tree' was moved into subr.el from cl.el
,----
|
| committer: Colin Walters <walters@gnu.org>
| timestamp: Sat 2002-06-08 20:48:15 +0000
| message:
| (copy-list): Moved here from cl.el.
| (copy-tree): Renamed here from `cl-copy-tree' in cl.el.
|
`----
--
/s_P\
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#7083: Why is `copy-tree's symbol-plist carrying side-effect-free error-free?
2010-09-22 6:31 bug#7083: Why is `copy-tree's symbol-plist carrying side-effect-free error-free? MON KEY
@ 2010-09-22 21:35 ` Andreas Schwab
2010-09-23 5:23 ` MON KEY
0 siblings, 1 reply; 4+ messages in thread
From: Andreas Schwab @ 2010-09-22 21:35 UTC (permalink / raw)
To: MON KEY; +Cc: 7083-done
MON KEY <monkey@sandpframing.com> writes:
> It (potentially) `nconc's `nreverse's and `aset's the TREE arg recursively.
Only the copy.
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#7083: Why is `copy-tree's symbol-plist carrying side-effect-free error-free?
2010-09-22 21:35 ` Andreas Schwab
@ 2010-09-23 5:23 ` MON KEY
2010-09-23 22:19 ` Stefan Monnier
0 siblings, 1 reply; 4+ messages in thread
From: MON KEY @ 2010-09-23 5:23 UTC (permalink / raw)
To: Andreas Schwab; +Cc: 7083
On Wed, Sep 22, 2010 at 5:35 PM, Andreas Schwab <schwab@linux-m68k.org> wrote:
> MON KEY <monkey@sandpframing.com> writes:
>
>> It (potentially) `nconc's `nreverse's and `aset's the TREE arg recursively.
>
> Only the copy.
>
Only for the copy of a list.
Why has this bug been marked done?
When copy-tree copies vectors they share structure.
(let ((orig '((a b) (c d) (e f) (g h)))
new-cp)
(setq new-cp (copy-tree orig))
(equal (elt
(prog1 orig
(setf (car new-cp) "bubba")) 0)
'(a b)))
;=> t
(let ((orig [[a b] [c d] [e f] [g h]])
new-cp)
(setq new-cp (copy-tree orig))
(string-equal (aref (prog1 orig
(aset new-cp 0 "bubba"))
0)
"bubba"))
;=> t
Shouldn't idx 0 of the orig tree still be [a b]?
If not, it should be documented that when copy-tree copies vectors the
"copy" will share structure just as with `copy-sequence'.
Regardless, simply marking the bug report as done with only a terse 3
word reply is obnoxious and not the least bit helpful for anyone else
referencing this report in the future, esp. as there does appear to be
a bug.
> Andreas.
--
/s_P\
^ permalink raw reply [flat|nested] 4+ messages in thread* bug#7083: Why is `copy-tree's symbol-plist carrying side-effect-free error-free?
2010-09-23 5:23 ` MON KEY
@ 2010-09-23 22:19 ` Stefan Monnier
0 siblings, 0 replies; 4+ messages in thread
From: Stefan Monnier @ 2010-09-23 22:19 UTC (permalink / raw)
To: MON KEY; +Cc: 7083, Andreas Schwab
> Why has this bug been marked done?
> When copy-tree copies vectors they share structure.
C-h f copy-tree RET documents the second (optional) argument which
affects this behavior. So it looks perfectly correct, and documented.
Stefan
^ permalink raw reply [flat|nested] 4+ messages in thread
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2010-09-22 6:31 bug#7083: Why is `copy-tree's symbol-plist carrying side-effect-free error-free? MON KEY
2010-09-22 21:35 ` Andreas Schwab
2010-09-23 5:23 ` MON KEY
2010-09-23 22:19 ` Stefan Monnier
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