bug#25588: 26.0.50; Wishlist: shr could support some further CSS

[Lars Ingebrigtsen <larsi@gnus.org>]

This is just a reminder to myself, unless anybody else wants to have a
go at it:

shr (by design) disregards virtually all CSS because it has to be fast
enough.  Getting bogged down in details is a sure-fire way to become so
slow that it's not useful any more.

But shr already supports display: none i direct style attributes.  I
think shr could consider parsing inline CSS sections (in emails and the
like) and make <div class="foo"> with .foo { display: inline } without a
huge performance penalty.

Implementing this should be easy, but benchmarking should be performed
before committing.


In GNU Emacs 26.0.50.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.14.5)
 of 2017-01-30 built on stories
Repository revision: ab96c8509736a7ed622916ad2749ff356e520d02
Windowing system distributor 'The X.Org Foundation', version 11.0.11604000
System Description:	Debian GNU/Linux 8.6 (jessie)

Recent messages:
Mark set
Mark saved where search started [2 times]
Mark set
Mark saved where search started [2 times]
Buffer shr.el modified; save it? (y or n) y
Saving file /home/larsi/src/emacs/trunk/lisp/net/shr.el...
Wrote /home/larsi/src/emacs/trunk/lisp/net/shr.el
Finding changes in /home/larsi/src/emacs/trunk/lisp/net/shr.el...
Discard changes in /home/larsi/src/emacs/trunk/lisp/net/shr.el? (y or n) y
Reverting /home/larsi/src/emacs/trunk/lisp/net/shr.el...done

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS
NOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
  value of $LC_ALL: en_US.UTF-8
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Emacs-Lisp

Minor modes in effect:
  diff-auto-refine-mode: t
  global-whitespace-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-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

Load-path shadows:
/home/larsi/src/cddb.el/expect hides /home/larsi/lisp/expect
/home/larsi/src/cddb.el/captitle hides /home/larsi/lisp/captitle
/home/larsi/src/clock.el/clock hides /home/larsi/lisp/clock
~/pgnus/contrib/vcard hides /home/larsi/lisp/vcard
/home/larsi/src/pvr.el/pvr hides /home/larsi/lisp/pvr
~/lisp/zenirc-2.112/src/zenirc-example hides /home/larsi/lisp/zenirc-example
~/pgnus/contrib/compface hides /home/larsi/src/emacs/trunk/lisp/image/compface

Features:
(shadow ecomplete emacsbug sendmail copyright vc vc-dispatcher edebug
misearch multi-isearch vc-git diff-mode map sort smiley ansi-color
gnus-cite mm-archive gnus-async gnus-dup qp gnus-ml gmane spam-gmane dns
mm-url disp-table gnus-fun gnus-mdrtn gnus-topic pop3 nndoc nnmbox utf-7
nnml nnfolder network-stream starttls nnir spam-report spam spam-stat
gnus-uu yenc gnus-delay gnus-draft gnus-agent gnus-srvr gnus-score
score-mode nnvirtual nntp gnus-cache gnus-msg gnus-art mm-uu mml2015
mm-view mml-smime smime dig gnus-sum nndraft nnmh gnus-group gnus-undo
gnus-start gnus-cloud nnimap utf7 netrc nnoo parse-time gnus-spec
gnus-win nnmail gnus-int gnus-range mail-source message format-spec
rfc822 mml mml-sec epa epg mailabbrev gmm-utils mailheader gnus nnheader
gnus-util rmail rmail-loaddefs mail-utils whitespace movie mkv shr svg
imdb dom pvr debug debbugs-gnu easy-mmode derived debbugs soap-client
mm-decode mm-bodies mm-encode url-http tls gnutls url-auth mail-parse
rfc2231 rfc2047 rfc2045 mm-util ietf-drums mail-prsvr url-gw nsm puny
url url-proxy url-privacy url-expand url-methods url-history url-cookie
url-domsuf url-util mailcap warnings rng-xsd rng-dt rng-util xsd-regexp
xml ido flyspell ispell benchmark w3m browse-url doc-view subr-x dired
dired-loaddefs image-mode timezone w3m-hist w3m-fb w3m-ems wid-edit
w3m-ccl ccl w3m-favicon w3m-image w3m-proc w3m-util add-log mail-extr
jka-compr cl finder-inf package epg-config url-handlers url-parse
auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs
password-cache url-vars seq byte-opt gv bytecomp byte-compile cl-extra
help-mode easymenu cconv cl-loaddefs pcase cl-lib time-date mule-util
tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type
mwheel term/x-win x-win term/common-win x-dnd tool-bar dnd fontset image
regexp-opt fringe tabulated-list replace newcomment text-mode elisp-mode
lisp-mode prog-mode register page menu-bar rfn-eshadow isearch timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame 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 charscript case-table epa-hook jka-cmpr-hook help
simple abbrev obarray minibuffer cl-preloaded 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 dbusbind inotify dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty
make-network-process emacs)

Memory information:
((conses 16 690424 45358)
 (symbols 48 171172 1)
 (miscs 40 1699 616)
 (strings 32 220714 11228)
 (string-bytes 1 8899852)
 (vectors 16 43109)
 (vector-slots 8 1699378 217800)
 (floats 8 6775 482)
 (intervals 56 6045 1105)
 (buffers 976 44)
 (heap 1024 117771 3510))

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