From: Corwin Brust <corwin@bru.st>
To: goncholden <goncholden@protonmail.com>
Cc: Help Gnu Emacs mailing list <help-gnu-emacs@gnu.org>,
Emanuel Berg <moasenwood@zoho.eu>
Subject: Re: Function passing flag
Date: Tue, 8 Mar 2022 14:15:16 -0600 [thread overview]
Message-ID: <CAJf-WoR7ZX19YkXBnaHJ5n51FULkyK2PCpuEDuCSUJVsRX6JGw@mail.gmail.com> (raw)
In-Reply-To: <CAJf-WoS68on6yMAu6T=VYpUGr+p8OWeiqmm9bh5D7N6TGujr4Q@mail.gmail.com>
Apologies, I answered only half of your question, I think. As to
where you can read about this:
I recommend reading the entire Functions section of the elisp manual
however you can get to the specific section that introduces optional
arguments via:
M-: (info "(elisp)Defining Functions") RET
On Tue, Mar 8, 2022 at 2:09 PM Corwin Brust <corwin@bru.st> wrote:
>
> On Tue, Mar 8, 2022 at 1:36 PM goncholden <goncholden@protonmail.com> wrote:
> >
> > How does one do it with an optional argument? Where can I read about this?
> >
>
> A function with an optional argument ARG might look like this:
>
> (defun my:own-fun (&optional arg)
> "Do something. When ARG is non-nil do it a lot."
> (if arg
> ;; when ARG is true we run this
> (do-stuff)
> ;; else we run this
> (do-more-or-different-stuff)))
>
> Note, if you are defining a command (a function you will bind to a key
> or otherwise use interactively), you will want to to use
> (interactive), usually placed at the start of the function definition,
> so just after the docstring.
next prev parent reply other threads:[~2022-03-08 20:15 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-08 12:24 Function passing flag goncholden via Users list for the GNU Emacs text editor
2022-03-08 18:00 ` Emanuel Berg via Users list for the GNU Emacs text editor
2022-03-08 19:00 ` goncholden
2022-03-08 19:14 ` Emanuel Berg via Users list for the GNU Emacs text editor
2022-03-08 19:35 ` goncholden
2022-03-08 20:09 ` Corwin Brust
2022-03-08 20:15 ` Corwin Brust [this message]
2022-03-08 20:28 ` goncholden
2022-03-08 20:42 ` Corwin Brust
2022-03-08 20:55 ` goncholden
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=CAJf-WoR7ZX19YkXBnaHJ5n51FULkyK2PCpuEDuCSUJVsRX6JGw@mail.gmail.com \
--to=corwin@bru.st \
--cc=goncholden@protonmail.com \
--cc=help-gnu-emacs@gnu.org \
--cc=moasenwood@zoho.eu \
/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).