Commit: runtime(html): match plain tag and attribute names as keywords

[Christian Brabandt]

runtime(html): match plain tag and attribute names as keywords

Commit: https://github.com/vim/vim/commit/964a495bef698368f4e200b1d22d63da27f47948
Author: Julien Voisin <julien...@dustri.org>
Date: Thu Aug 27 20:51:07 2026 +0000

runtime(html): match plain tag and attribute names as keywords

Problem: Several tag and attribute names are highlighted with regular
expression alternations even though they are plain words. A
:syn-match with an alternation is retried at nearly every
position of every tag.
Solution: Move the plain-word tag names (b, i, u, em, strong, head,
body, title, h1-h6) and the "label", "href" and "title"
attribute names into syn-keyword lists, leaving only the
genuinely hyphenated names "accept-charset" and "http-equiv"
as matches.

Profiling a 6000-line HTML file with :syntime, the converted rules drop
from a combined 0.044s to 0.004s, lowering total per-rule syntax time
by about 15%. Highlighting is unchanged except that a bare valueless
"href" attribute is now highlighted as an attribute, consistent with a
bare "title", which already behaved that way.

closes: #21155

Signed-off-by: Julien Voisin <julien...@dustri.org>
Signed-off-by: Doug Kearns <dougk...@gmail.com>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/runtime/syntax/html.vim b/runtime/syntax/html.vim
index 0e615b70f..7c9f87267 100644
--- a/runtime/syntax/html.vim
+++ b/runtime/syntax/html.vim
@@ -6,6 +6,7 @@
" Last Change: 2023 Nov 28
" 2024 Jul 30 by Vim Project: increase syn-sync-minlines to 250
" 2025 May 10 by Vim Project: update comment
+" 2026 Aug 26 by Vim Project: match plain tag/attribute names as keywords

" See :help html.vim for some comments and a description of the options

@@ -49,7 +50,7 @@ syn keyword htmlTagName contained input isindex kbd li link map menu
syn keyword htmlTagName contained meta ol option param pre p samp span
syn keyword htmlTagName contained select small strike sub sup
syn keyword htmlTagName contained table td textarea th tr tt ul var xmp
-syn match htmlTagName contained "\<\%(b\|i\|u\|h[1-6]\|em\|strong\|head\|body\|title\)\>"
+syn keyword htmlTagName contained b i u em strong head body title h1 h2 h3 h4 h5 h6

" new html 4.0 tags
syn keyword htmlTagName contained abbr acronym bdo button col colgroup
@@ -80,15 +81,13 @@ syn keyword htmlArg contained align alink alt archive background bgcolor
syn keyword htmlArg contained border bordercolor cellpadding
syn keyword htmlArg contained cellspacing checked class clear code codebase color
syn keyword htmlArg contained cols colspan content coords enctype face
-syn keyword htmlArg contained gutter height hspace id
+syn keyword htmlArg contained gutter height href hspace id
syn keyword htmlArg contained link lowsrc marginheight
syn keyword htmlArg contained marginwidth maxlength method name prompt
-syn keyword htmlArg contained rel rev rows rowspan scrolling selected shape
-syn keyword htmlArg contained size src start target text type url
+syn keyword htmlArg contained rel rev role rows rowspan scrolling selected shape
+syn keyword htmlArg contained size src start target text title type url
syn keyword htmlArg contained usemap ismap valign value vlink vspace width wrap
-syn match htmlArg contained "\<\%(http-equiv\|href\|title\)="me=e-1
-
-syn keyword htmlArg contained role
+syn match htmlArg contained "\<http-equiv="me=e-1

" ARIA attributes {{{1
let s:aria =<< trim END
@@ -165,11 +164,11 @@ syn match htmlArg contained "\<z-index\>"
syn keyword htmlTagName contained marquee

" html 4.0 arg names
-syn match htmlArg contained "\<\%(accept-charset\|label\)\>"
+syn match htmlArg contained "\<accept-charset\>"
syn keyword htmlArg contained abbr accept accesskey axis char charoff charset
syn keyword htmlArg contained cite classid codetype compact data datetime
syn keyword htmlArg contained declare defer dir disabled for frame
-syn keyword htmlArg contained headers hreflang lang language longdesc
+syn keyword htmlArg contained headers hreflang label lang language longdesc
syn keyword htmlArg contained multiple nohref nowrap object profile readonly
syn keyword htmlArg contained rules scheme scope span standby style
syn keyword htmlArg contained summary tabindex valuetype version