From: Eric Abrahamsen <eric@ericabrahamsen.net>
To: Michael Heerdegen <michael_heerdegen@web.de>
Cc: 34708@debbugs.gnu.org
Subject: bug#34708: alist-get has unclear documentation
Date: Mon, 04 Mar 2019 14:49:15 -0800 [thread overview]
Message-ID: <878sxui7bo.fsf@ericabrahamsen.net> (raw)
In-Reply-To: <CAARdmY0+2Z-=P9RD3JXkuFV5mkeS=sXCchCfo_omVv6dWBW7vg@mail.gmail.com>
On 03/04/19 19:22 PM, Michael Heerdegen wrote:
[...]
> This makes a call like
>
> (setf (alist-get key alist default) default)
>
> ambiguous: the "goal" (which is making (alist-get key alist default)
> eval to DEFAULT) can be reached in two ways: (1) by making KEY being
> associated with DEFAULT in ALIST and (2) by removing any existing
> association for KEY.
>
> You can choose which behavior you want via the REMOVE argument which
> comes after the DEFAULT arg: specifying REMOVE non-nil gives you (2) -
> remove it - else you get (1).
Thanks for spelling all this out! I guess my confusion is the
interaction of REMOVE with DEFAULT. Why does REMOVE only do anything if
the value being set is equal to the DEFAULT? If they are not equal,
REMOVE is ignored, and the value is set. How does that make sense?
next prev parent reply other threads:[~2019-03-04 22:49 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-02 4:50 bug#34708: alist-get has unclear documentation Miguel V. S. Frasson
2019-03-02 9:25 ` Michael Heerdegen
2019-03-02 15:40 ` Miguel V. S. Frasson
2019-03-02 18:10 ` Michael Heerdegen
2019-03-02 19:06 ` Eric Abrahamsen
2019-03-03 0:15 ` Phil Sainty
2019-03-03 12:50 ` Michael Heerdegen
2019-03-19 1:35 ` Michael Heerdegen
2019-03-02 19:51 ` Miguel V. S. Frasson
2019-03-02 20:32 ` Eric Abrahamsen
2019-03-03 11:32 ` Miguel V. S. Frasson
2019-03-03 12:21 ` Michael Heerdegen
2019-03-03 15:51 ` Drew Adams
2019-03-03 16:49 ` Eric Abrahamsen
2019-03-04 16:24 ` Eric Abrahamsen
2019-03-04 16:38 ` Michael Heerdegen
2019-03-04 17:16 ` Eric Abrahamsen
2019-03-04 18:22 ` Michael Heerdegen
2019-03-04 22:49 ` Eric Abrahamsen [this message]
2019-03-05 12:35 ` Michael Heerdegen
2019-03-05 22:50 ` Eric Abrahamsen
2019-03-06 0:16 ` Drew Adams
2019-03-11 13:39 ` Michael Heerdegen
2019-03-11 14:52 ` Drew Adams
2019-03-11 16:19 ` Michael Heerdegen
2019-03-11 17:48 ` Drew Adams
2019-03-12 13:04 ` Michael Heerdegen
2019-03-12 14:48 ` Drew Adams
2019-03-12 16:08 ` Michael Heerdegen
2019-03-12 16:48 ` Drew Adams
2019-03-12 17:45 ` Michael Heerdegen
2019-03-12 13:12 ` Michael Heerdegen
2019-03-12 14:53 ` Drew Adams
2019-03-12 15:38 ` Michael Heerdegen
2019-03-12 16:18 ` Drew Adams
2019-03-12 17:55 ` Michael Heerdegen
2019-03-15 15:54 ` Michael Heerdegen
2019-03-15 18:48 ` Eric Abrahamsen
2019-03-27 22:31 ` Michael Heerdegen
2019-04-19 1:33 ` Michael Heerdegen
2019-04-19 2:24 ` bug#34708: Thanks Miguel V. S. Frasson
2019-04-19 4:18 ` Michael Heerdegen
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