unofficial mirror of help-gnu-emacs@gnu.org
 help / color / mirror / Atom feed
From: Stefan Monnier via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>
To: help-gnu-emacs@gnu.org
Subject: Re: Generic functions: Specializers like `or' or `memq'?
Date: Sat, 06 Nov 2021 19:29:02 -0400	[thread overview]
Message-ID: <jwvv914amqi.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: 87ilx6qo86.fsf@zoho.eu

Emanuel Berg via Users list for the GNU Emacs text editor [2021-11-05 22:36:25] wrote:
> Stefan Monnier via Users list for the GNU Emacs text editor wrote:
>>> My earliest confusion began when I decided that if I could
>>> find the part of the code that runs the `eql' specializer
>>> (or do we call it the `eql' generalizer?) and then worked
>>> back from there, I would be able to make sense of
>>> everything. But I couldn't even find the bit of code that
>>> looks like (eql <val> <tag>)! And still can't.
>>
>> Nah, that would be too easy. Instead it happens implicitly
>> via a lookup in a hash-table.
>>
>> I suspect that the code for cl-defstruct specializer might
>> be easier to understand in this respect.
>
> What's the typical use case for this?

Not sure what "this" refers to.  If you're talking about the use case
for adding new specializers/generalizers, it's quite rare.
It's mostly a detail of `cl-generic.el` used internally.


        Stefan




  reply	other threads:[~2021-11-06 23:29 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-04 17:31 Generic functions: Specializers like `or' or `memq'? Eric Abrahamsen
2021-11-05 21:17 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-11-05 21:36   ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-11-06 23:29     ` Stefan Monnier via Users list for the GNU Emacs text editor [this message]
2021-11-06 23:52       ` Emanuel Berg via Users list for the GNU Emacs text editor
  -- strict thread matches above, loose matches on Subject: below --
2021-11-03 17:17 Michael Heerdegen
2021-11-03 18:21 ` Philip Kaludercic
2021-11-03 21:10   ` Michael Heerdegen
2021-11-03 21:32     ` Eric Abrahamsen
2021-11-03 23:19       ` Michael Heerdegen
2021-11-03 23:38         ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-11-04  0:26           ` Michael Heerdegen
2021-11-04  1:31       ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-11-04  2:34         ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-11-04  4:01           ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-11-06 22:32         ` Michael Heerdegen
2021-11-06 23:36           ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-11-07  1:48             ` Michael Heerdegen
2021-11-21 19:43               ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-11-23  8:16                 ` Michael Heerdegen

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=jwvv914amqi.fsf-monnier+emacs@gnu.org \
    --to=help-gnu-emacs@gnu.org \
    --cc=monnier@iro.umontreal.ca \
    /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.
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).