unofficial mirror of help-gnu-emacs@gnu.org
 help / color / mirror / Atom feed
From: Michael Heerdegen <michael_heerdegen@web.de>
To: help-gnu-emacs@gnu.org
Subject: Re: Help setting nadvice for indent-region
Date: Thu, 11 Feb 2016 20:14:52 +0100	[thread overview]
Message-ID: <87vb5vys7n.fsf@web.de> (raw)
In-Reply-To: CAFyQvY2B7jtzo=3+MM_LPK9DfqLGdc8XeprMa1XHar1yQD1=FQ@mail.gmail.com

Kaushal Modi <kaushal.modi@gmail.com> writes:

> But what should be the return value of an :around advice fn?

The around advice function should return the value you want the adviced
function to return.  This will very often be the value gotten by
applying the original function (aka "don't change the return value"), or
a value derived from it.  Or something completely different.  The
advised function will return just this value as well.  The around advice
works like this:

  (lambda (&rest r) (apply FUNCTION OLDFUN r))

where FUNCTION is the advice defined.  As you see, the combined call has
the call of FUNCTION at the outermost level.

When several advices are in effect, the order is significant.

But note that this is not the case for all advice types.

Michael.




  reply	other threads:[~2016-02-11 19:14 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-05 23:49 Help setting nadvice for indent-region Kaushal Modi
2016-02-05 23:58 ` Kaushal Modi
2016-02-06  0:00   ` Kaushal Modi
2016-02-06  0:30   ` Emanuel Berg
2016-02-06  3:31     ` Kaushal Modi
2016-02-06 10:43 ` Michael Heerdegen
2016-02-07  3:12   ` Kaushal Modi
2016-02-07 17:46     ` Kaushal Modi
2016-02-07 18:51       ` John Mastro
2016-02-08  0:03         ` Emanuel Berg
2016-02-08  4:22           ` Kaushal Modi
2016-02-08 17:05             ` Eli Zaretskii
2016-02-08 17:27               ` Kaushal Modi
2016-02-09  3:07             ` Emanuel Berg
2016-02-08 20:03           ` John Mastro
2016-02-08 23:13             ` Emanuel Berg
2016-02-11 14:02         ` Stefan Monnier
2016-02-11 17:36           ` Kaushal Modi
2016-02-11 18:10             ` Michael Heerdegen
2016-02-11 18:47               ` Kaushal Modi
2016-02-11 18:56                 ` Kaushal Modi
2016-02-11 19:14                   ` Michael Heerdegen [this message]
2016-02-11 20:15                     ` Kaushal Modi
2016-02-11 20:38                       ` Kaushal Modi
2016-02-12 14:09                         ` Michael Heerdegen
2016-02-12 14:21                           ` Michael Heerdegen
2016-02-12 16:02                             ` Kaushal Modi
2016-02-12 19:04                               ` Michael Heerdegen
2016-02-12 13:57                       ` Michael Heerdegen
2016-02-11 19:03                 ` Michael Heerdegen
2016-02-07 23:48       ` Emanuel Berg

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=87vb5vys7n.fsf@web.de \
    --to=michael_heerdegen@web.de \
    --cc=help-gnu-emacs@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.
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).