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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.



  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

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