From: Philipp <p.stephani2@gmail.com>
To: Marcin Borkowski <mbork@mbork.pl>
Cc: Help Gnu Emacs mailing list <help-gnu-emacs@gnu.org>
Subject: Re: Which Elisp types are mutable?
Date: Mon, 5 Jul 2021 20:41:58 +0200 [thread overview]
Message-ID: <4AA1E624-B979-4B08-8AE0-E33A1C9A0E94@gmail.com> (raw)
In-Reply-To: <8735tw9l14.fsf@mbork.pl>
> Am 05.06.2021 um 21:19 schrieb Marcin Borkowski <mbork@mbork.pl>:
>
>
> On 2021-06-05, at 14:58, Philipp <p.stephani2@gmail.com> wrote:
>
>>> Am 05.06.2021 um 13:22 schrieb Marcin Borkowski <mbork@mbork.pl>:
>>>
>>>
>>> On 2021-06-03, at 14:11, Philipp <p.stephani2@gmail.com> wrote:
>>>
>>>>> Am 03.06.2021 um 06:03 schrieb Marcin Borkowski <mbork@mbork.pl>:
>>>>>
>>>>> Well, the subject says it all. I could find an explicit, comprehensive
>>>>> list of mutable (or immutable) types in the Elisp manual. Is it there
>>>>> somewhere?
>>>>
>>>> Mutability is a property of objects, not types.
>>>> Some objects (numbers) are always immutable, others (markers, buffers, ...) are always mutable. But objects of most "interesting" types (strings, lists, vectors, symbols) can be either mutable or immutable.
>>>> Some time ago, I filed https://debbugs.gnu.org/cgi/bugreport.cgi?bug=43557 to document which objects are mutable, but unfortunately it's not yet fixed.
>>>
>>> Thanks. However, I still don't understand. How can a list be
>>> immutable? What about a string? I thought these are _always_ mutable
>>> (although in some cases you must not mutate them, because if you do, bad
>>> things could happen
>>
>> "You must not mutate them" is the definition of immutable.
>
> Well, in my book, "you can't mutate them" is. You always /can/ mutate
> a string, but of you do it in certain circumstances, you're asking for
> trouble.
You can mutate all objects, because all of them are stored in mutable memory.
For a reference manual, "you're asking for trouble" isn't a terribly useful statement.
next prev parent reply other threads:[~2021-07-05 18:41 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-03 4:03 Which Elisp types are mutable? Marcin Borkowski
2021-06-03 12:11 ` Philipp
2021-06-05 11:22 ` Marcin Borkowski
2021-06-05 12:58 ` Philipp
2021-06-05 14:25 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-07-05 18:40 ` Philipp
2021-07-05 20:19 ` Stefan Monnier
2021-07-05 20:44 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-07-05 20:58 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-07-05 21:03 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-06-05 19:19 ` Marcin Borkowski
2021-06-05 20:17 ` [External] : " Drew Adams
2021-06-05 20:36 ` Dmitry Gutov
2021-06-06 1:57 ` Drew Adams
2021-07-05 18:41 ` Philipp [this message]
2021-07-05 18:48 ` Eli Zaretskii
2021-07-05 18:55 ` tomas
2021-07-05 19:26 ` [External] : " Drew Adams
2021-07-05 19:40 ` tomas
2021-07-05 20:03 ` Drew Adams
2021-07-05 20:12 ` tomas
2021-07-05 20:39 ` Drew Adams
2021-07-05 20:58 ` Emanuel Berg via Users list for the GNU Emacs text editor
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