emacs-orgmode@gnu.org archives
 help / color / mirror / code / Atom feed
From: Stefan Kangas <stefan@marxist.se>
To: Neil Jerram <neiljerram@gmail.com>
Cc: Org-mode <emacs-orgmode@gnu.org>
Subject: Re: [PATCH] Remove redundant 'function's around lambda
Date: Thu, 19 Nov 2020 06:51:01 -0800	[thread overview]
Message-ID: <CADwFkmn_bH0k+f50ST8cv1M4azsNmKdvXjbsDS2uHHAqmi-RFg@mail.gmail.com> (raw)
In-Reply-To: <CAKuG=vufnWctEh133-OQdUBMOtcz6dH+Nny=1ENCW4YPLoz=Tg@mail.gmail.com>

Neil Jerram <neiljerram@gmail.com> writes:

>> I've been working on removing redundant `function' around `lambda' in
>> Emacs core,
>
> I'm slightly curious about the history and reasoning around this.  If I
> understand correctly, (lambda ...) on its own has always worked, and it's
> never been strictly necessary to add (quote ...) or (function ...) around
> it.  Then sometime (Emacs 19 or later, I think) it started being
> recommended to use (function ...).
>
> Do you know why that recommendation started, and should I understand that
> the reasoning for it has now evaporated?

Correct, there is no reason to do this.

I don't know the history here, and there are people on emacs-devel that
would know better.

I _suspect_ that the byte-compiler first got the capability to optimize
calls to anonymous functions, but that it required to explicitly marked
as such with `function'.  Later, it grew the capability to recognize
lambda as such automatically.  But I don't know if that is correct; it's
just a guess.  In any case, they are no longer needed as lambda and
lambda+function are equivalent.

(Note that the worst thing here is to do `(quote (lambda ...))' as that
defeats byte-compiler optimizations altogether.)


  reply	other threads:[~2020-11-19 14:52 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-17 16:55 Stefan Kangas
2020-11-19  3:07 ` Kyle Meyer
2020-11-19  3:44   ` Stefan Kangas
2020-12-14  6:49   ` Bastien
2020-12-23  5:11     ` Kyle Meyer
2020-11-19 10:44 ` Neil Jerram
2020-11-19 14:51   ` Stefan Kangas [this message]
2020-11-19 15:16     ` Neil Jerram

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.orgmode.org/

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

  git send-email \
    --in-reply-to=CADwFkmn_bH0k+f50ST8cv1M4azsNmKdvXjbsDS2uHHAqmi-RFg@mail.gmail.com \
    --to=stefan@marxist.se \
    --cc=emacs-orgmode@gnu.org \
    --cc=neiljerram@gmail.com \
    --subject='Re: [PATCH] Remove redundant '\''function'\''s around lambda' \
    /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

Code repositories for project(s) associated with this inbox:

	https://git.savannah.gnu.org/cgit/emacs/org-mode.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).