GNU bug report logs - #21048
letrec is not documented in the manual

Previous Next

To add a comment to this bug, you must first unarchive it, by sending
a message to control AT debbugs.gnu.org, with unarchive 21048 in the body.
You can then email your comments to 21048 AT debbugs.gnu.org in the normal way.

Toggle the display of automated, internal messages from the tracker.

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Rustom Mody <rustompmody <at> gmail.com>
To: bug-gnu-emacs <at> gnu.org
Subject: 24.4; Letrec docs
Date: Mon, 13 Jul 2015 21:29:13 +0530

[Message part 1 (text/plain, inline)]

I find letrec is not in the info pages though it has a brief
'describe-function' result.
Eli Zaretsii suggested a bug-report, so here it is!



In GNU Emacs 24.4.1 (x86_64-pc-linux-gnu, GTK+ Version 3.14.9)
 of 2015-03-21 on kissel, modified by Debian
Windowing system distributor `The X.Org Foundation', version 11.0.11701000
System Description:    Ubuntu 15.04

Configured using:
 `configure --build x86_64-linux-gnu --prefix=/usr
 --sharedstatedir=/var/lib --libexecdir=/usr/lib
 --localstatedir=/var/lib --infodir=/usr/share/info
 --mandir=/usr/share/man --with-pop=yes
 --enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.4/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.4/site-lisp:/usr/share/emacs/site-lisp
 --build x86_64-linux-gnu --prefix=/usr --sharedstatedir=/var/lib
 --libexecdir=/usr/lib --localstatedir=/var/lib
 --infodir=/usr/share/info --mandir=/usr/share/man --with-pop=yes
 --enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.4/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.4/site-lisp:/usr/share/emacs/site-lisp
 --with-x=yes --with-x-toolkit=gtk3 --with-toolkit-scroll-bars
 'CFLAGS=-g -O2 -fstack-protector-strong -Wformat
 -Werror=format-security -Wall' CPPFLAGS=-D_FORTIFY_SOURCE=2
 'LDFLAGS=-Wl,-Bsymbolic-functions -Wl,-z,relro''

Important settings:
  value of $LC_MONETARY: en_US.UTF-8
  value of $LC_NUMERIC: en_US.UTF-8
  value of $LC_TIME: en_US.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
M-x r e p o r t <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util help-fns mail-prsvr mail-utils time-date tooltip electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar
dnd fontset image regexp-opt fringe tabulated-list newcomment lisp-mode
prog-mode register page menu-bar rfn-eshadow timer select scroll-bar
mouse jit-lock font-lock syntax facemenu font-core frame cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev
minibuffer nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote make-network-process
dbusbind gfilenotify dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)

Memory information:
((conses 16 71135 7794)
 (symbols 48 17572 0)
 (miscs 40 35 113)
 (strings 32 9054 4369)
 (string-bytes 1 249011)
 (vectors 16 8912)
 (vector-slots 8 383118 18327)
 (floats 8 63 68)
 (intervals 56 216 0)
 (buffers 960 11)
 (heap 1024 21493 1000))

[Message part 2 (text/html, inline)]

Message #10 received at 21048 <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Rustom Mody <rustompmody <at> gmail.com>
Cc: 21048 <at> debbugs.gnu.org
Subject: Re: bug#21048: 24.4; Letrec docs
Date: Wed, 09 Oct 2019 06:06:51 +0200

Rustom Mody <rustompmody <at> gmail.com> writes:

> I find letrec is not in the info pages though it has a brief
> 'describe-function' result.
> Eli Zaretsii suggested a bug-report, so here it is!

I have now documented letrec in the Emacs 27 Emacs Lisp manual.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Message #17 received at 21048 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Lars Ingebrigtsen <larsi <at> gnus.org>
Cc: rustompmody <at> gmail.com, 21048 <at> debbugs.gnu.org
Subject: Re: bug#21048: 24.4; Letrec docs
Date: Wed, 09 Oct 2019 20:15:08 +0300

> From: Lars Ingebrigtsen <larsi <at> gnus.org>
> Date: Wed, 09 Oct 2019 06:06:51 +0200
> Cc: 21048 <at> debbugs.gnu.org
> 
> Rustom Mody <rustompmody <at> gmail.com> writes:
> 
> > I find letrec is not in the info pages though it has a brief
> > 'describe-function' result.
> > Eli Zaretsii suggested a bug-report, so here it is!
> 
> I have now documented letrec in the Emacs 27 Emacs Lisp manual.

Thanks, but I have trouble understanding what the text you wrote
says.  I think it needs clarifying, or maybe a descriptive enough
example.

Message #20 received at 21048 <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: rustompmody <at> gmail.com, 21048 <at> debbugs.gnu.org
Subject: Re: bug#21048: 24.4; Letrec docs
Date: Wed, 09 Oct 2019 19:33:20 +0200

Eli Zaretskii <eliz <at> gnu.org> writes:

> Thanks, but I have trouble understanding what the text you wrote
> says.  I think it needs clarifying, or maybe a descriptive enough
> example.

Yeah, it's pretty subtle what the difference is -- feel free to rewrite
to make it clearer.

I went through the tree looking for a real-life example of when this
macro is useful, and the first half-dozen examples I looked at could
have been written with let* instead and worked just as well, as far as I
can tell.

But I found one in elisp-mode.el and I adapted it slightly and added
this to the manual:

----

For instance, here's a closure that removes itself from a hook after
being run once:

@lisp
(letrec ((hookfun (lambda ()
                    (message "Run once")
                    (remove-hook 'post-command-hook hookfun))))
  (add-hook 'post-command-hook hookfun))
@end lisp


-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.