Subject: bug#52063: 28.0.60; Confusing presentation of lambda

From: Eli Zaretskii <[email-masked]>
Date: Tue, 23 Nov 2021 20:56:20 +0200

To reproduce:

  . emacs -Q
  . Type into *scratch:

    (add-hook 'mail-mode-hook
	      #'(lambda () (setq flyspell-generic-check-word-p
			         'mail-mode-flyspell-verify)))

  . Evaluate the above expression with "C-x C-e"
  . Type into *scratch*:

    mail-mode-hook C-j

  . The result:

     ((closure (t) nil (setq flyspell-generic-check-word-p 'mail-mode-flyspell-verify)))

Why are we present a simple lambda as a closure? why confuse users
with something tricky instead of showing the lambda-form the user
typed?

In GNU Emacs 28.0.60 (build 156, i686-pc-mingw32)
 of 2021-11-23 built on HOME-C4E4A596F7
Repository revision: d791cd556d622accb935e4dd230023c485d1e07a
Repository branch: emacs-28
Windowing system distributor 'Microsoft Corp.', version 5.1.2600
System Description: Microsoft Windows XP Service Pack 3 (v5.1.0.2600)

Configured using:
 'configure -C --prefix=/d/usr --with-wide-int --with-modules
 --enable-checking=yes,glyphs 'CFLAGS=-O0 -gdwarf-4 -g3''

Configured features:
ACL GIF GMP GNUTLS HARFBUZZ JPEG JSON LCMS2 LIBXML2 MODULES NOTIFY
W32NOTIFY PDUMPER PNG RSVG SOUND THREADS TIFF TOOLKIT_SCROLL_BARS XPM
ZLIB

Important settings:
  value of $LANG: ENU
  locale-coding-system: cp1255

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-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
  indent-tabs-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr warnings emacsbug message rmc puny dired
dired-loaddefs rfc822 mml mml-sec epa derived epg rfc6068 epg-config
gnus-util rmail rmail-loaddefs auth-source cl-seq eieio eieio-core
cl-macs eieio-loaddefs password-cache json map text-property-search
time-date subr-x seq byte-opt gv bytecomp byte-compile cconv mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
cl-loaddefs cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils dabbrev iso-transl tooltip eldoc paren electric
uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel dos-w32
ls-lisp disp-table term/w32-win w32-win w32-vars term/common-win
tool-bar dnd fontset image regexp-opt fringe tabulated-list replace
newcomment text-mode lisp-mode prog-mode register page tab-bar menu-bar
rfn-eshadow isearch easymenu timer select scroll-bar mouse jit-lock
font-lock syntax font-core term/tty-colors frame minibuffer cl-generic
cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech
european ethiopic indian cyrillic chinese composite emoji-zwj charscript
charprop case-table epa-hook jka-cmpr-hook help simple abbrev obarray
cl-preloaded nadvice button loaddefs faces cus-face macroexp files
window text-properties overlay sha1 md5 base64 format env code-pages
mule custom widget hashtable-print-readable backquote threads w32notify
w32 lcms2 multi-tty make-network-process emacs)

Memory information:
((conses 16 57044 6934)
 (symbols 48 7874 2)
 (strings 16 21867 2892)
 (string-bytes 1 643712)
 (vectors 16 12975)
 (vector-slots 8 175379 9690)
 (floats 8 28 53)
 (intervals 40 316 141)
 (buffers 888 12))