unofficial mirror of bug-gnu-emacs@gnu.org 
 help / color / mirror / code / Atom feed
From: Adam Porter <adam@alphapapa.net>
To: 47368@debbugs.gnu.org
Subject: bug#47368: 28.0.50; map-elt returns nil without "deprecated" TESTFN
Date: Wed, 21 Jul 2021 10:34:14 -0500	[thread overview]
Message-ID: <CAO_b3FUCMYfUVzaz7p5bJv+hztXNxfr6=zXff0AnK5MaxiKf8g@mail.gmail.com> (raw)
In-Reply-To: <CACJP=3k08VBaj-O5KzqJyDbbkSpsOKLMFHtS5tEJfuSU2Wkmqg@mail.gmail.com>

Hi,

If I may chime in here, I'd like for map-elt to be usable with alists
having string keys.  It may not generally be very common in Elisp to
use alists with string keys, but in certain contexts, like preparing
JSON maps for encoding, it is.

In one of my packages, I came up with this workaround, which may be
tolerable when only used once in the whole package, but wouldn't be
nice to use more often:

    (cl-letf (((symbol-function 'alist-get)
               (lambda (key alist &optional _default _remove _testfn)
                 (cdr (assoc-string key alist)))))
      (let ((alist (list (cons "foo" "FOO")
                         (cons "bar" "BAR"))))
        (map-elt alist "foo")))  ;;=> "FOO"

In one of my other packages, I would have to use it more often, so I
guess I'll use alist-get for now.

In general, I think that using `equal' is a good solution.  It seems
like map-elt is intended to abstract over some Lisp implementation
details (to some extent, anyway), so using `equal' instead of `eq'
seems sensible, since I think it will usually DWIM.  If I really need
to compare Lisp object identity rather than equality, I'll probably
know how, and I probably won't need to do that as often, anyway.

Could this change be made for Emacs 28 and tagged for a 3.1 release of map.el?

Thanks,
Adam





  parent reply	other threads:[~2021-07-21 15:34 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-24 22:52 bug#47368: 28.0.50; map-elt returns nil without "deprecated" TESTFN dalanicolai
2021-03-24 23:24 ` Basil L. Contovounesios
2021-03-25  2:39   ` Michael Heerdegen
2021-03-25 14:48     ` dalanicolai
2021-03-25 15:33     ` bug#47368: [External] : " Drew Adams
2021-03-26 18:47       ` Basil L. Contovounesios
2021-03-26 20:04         ` Drew Adams
2021-03-26 20:23           ` Basil L. Contovounesios
2021-03-26 22:40             ` Drew Adams
2021-03-26 22:59               ` Basil L. Contovounesios
2021-03-26  3:59     ` Michael Heerdegen
2021-03-26  7:38       ` dalanicolai
2021-03-26 13:31       ` Stefan Monnier
2021-03-26 15:32         ` dalanicolai
2021-03-26 18:57         ` Basil L. Contovounesios
2021-03-26 23:18           ` Michael Heerdegen
2021-03-27 20:37           ` Basil L. Contovounesios
2021-03-26 23:23         ` Michael Heerdegen
2021-03-26 18:58     ` Basil L. Contovounesios
2021-07-21 15:34 ` Adam Porter [this message]
2021-07-22  2:15   ` Michael Heerdegen
2021-07-31  2:15     ` Michael Heerdegen
2021-09-13 14:06       ` Adam Porter
2021-09-14 14:40         ` Michael Heerdegen
2021-09-14 20:22           ` Basil L. Contovounesios via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-09-15  0:48             ` Michael Heerdegen
2021-09-15  9:26               ` Basil L. Contovounesios via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-09-15 12:39               ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-09-15 21:53                 ` Michael Heerdegen
2021-09-15 12:50             ` Basil L. Contovounesios via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-09-15 21:55               ` Michael Heerdegen
2021-09-21 12:42                 ` Basil L. Contovounesios via Bug reports for GNU Emacs, the Swiss army knife of text editors

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/emacs/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAO_b3FUCMYfUVzaz7p5bJv+hztXNxfr6=zXff0AnK5MaxiKf8g@mail.gmail.com' \
    --to=adam@alphapapa.net \
    --cc=47368@debbugs.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).