runtime(matchit): Update to Release 1.21

closes: #19109

Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/pack/dist/opt/matchit/autoload/matchit.vim

@@ -1,6 +1,6 @@
 "  matchit.vim: (global plugin) Extended "%" matching
 "  autload script of matchit plugin, see ../plugin/matchit.vim
-"  Last Change: May 20, 2024
+"  Last Change: Jan 06, 2025
 
 " Neovim does not support scriptversion
 if has("vimscript-4")
@@ -69,6 +69,26 @@ function matchit#Match_wrapper(word, forward, mode) range
     let startpos = [line("."), col(".")]
   endif
 
+  " Check for custom match function hook
+  if exists("b:match_function")
+    let MatchFunc = b:match_function
+    try
+      let result = call(MatchFunc, [a:forward])
+      if !empty(result)
+        call cursor(result)
+        return s:CleanUp(restore_options, a:mode, startpos)
+      endif
+    catch /.*/
+      if exists("b:match_debug")
+        echohl WarningMsg
+        echom 'matchit: b:match_function error: ' .. v:exception
+        echohl NONE
+      endif
+      return s:CleanUp(restore_options, a:mode, startpos)
+    endtry
+    " Empty result: fall through to regular matching
+  endif
+
   " First step:  if not already done, set the script variables
   "   s:do_BR   flag for whether there are backrefs
   "   s:pat     parsed version of b:match_words
@@ -91,7 +111,7 @@ function matchit#Match_wrapper(word, forward, mode) range
     let default = escape(&mps, '[$^.*~\\/?]') .. (strlen(&mps) ? "," : "") ..
       \ '\/\*:\*\/,#\s*if\%(n\=def\)\=:#\s*else\>:#\s*elif\%(n\=def\)\=\>:#\s*endif\>'
     " s:all = pattern with all the keywords
-    let match_words = match_words .. (strlen(match_words) ? "," : "") .. default
+    let match_words = s:Append(match_words, default)
     let s:last_words = match_words
     if match_words !~ s:notslash .. '\\\d'
       let s:do_BR = 0
@@ -101,8 +121,8 @@ function matchit#Match_wrapper(word, forward, mode) range
       let s:pat = s:ParseWords(match_words)
     endif
     let s:all = substitute(s:pat, s:notslash .. '\zs[,:]\+', '\\|', 'g')
-    " un-escape \, to ,
-    let s:all = substitute(s:all, '\\,', ',', 'g')
+    " un-escape \, and \: to , and :
+    let s:all = substitute(s:all, s:notslash .. '\zs\\\(:\|,\)', '\1', 'g')
     " Just in case there are too many '\(...)' groups inside the pattern, make
     " sure to use \%(...) groups, so that error E872 can be avoided
     let s:all = substitute(s:all, '\\(', '\\%(', 'g')
@@ -341,6 +361,18 @@ fun! s:InsertRefs(groupBR, prefix, group, suffix, matchline)
   return ini .. ":" .. tailBR
 endfun
 
+" String append item2 to item and add ',' in between items
+fun! s:Append(item, item2)
+  if a:item == ''
+    return a:item2
+  endif
+  " there is already a trailing comma, don't add another one
+  if a:item[-1:] == ','
+    return a:item .. a:item2
+  endif
+  return a:item .. ',' .. a:item2
+endfun
+
 " Input a comma-separated list of groups with backrefs, such as
 "   a:groups = '\(foo\):end\1,\(bar\):end\1'
 " and return a comma-separated list of groups with backrefs replaced:
@@ -538,8 +570,8 @@ fun! s:Choose(patterns, string, comma, branch, prefix, suffix, ...)
   else
     let currpat = substitute(current, s:notslash .. a:branch, '\\|', 'g')
   endif
-  " un-escape \, to ,
-  let currpat = substitute(currpat, '\\,', ',', 'g')
+  " un-escape \, and \: to , and :
+  let currpat = substitute(currpat, s:notslash .. '\zs\\\(:\|,\)', '\1', 'g')
   while a:string !~ a:prefix .. currpat .. a:suffix
     let tail = strpart(tail, i)
     let i = matchend(tail, s:notslash .. a:comma)
@@ -552,6 +584,8 @@ fun! s:Choose(patterns, string, comma, branch, prefix, suffix, ...)
     else
       let currpat = substitute(current, s:notslash .. a:branch, '\\|', 'g')
     endif
+    " un-escape \, and \: to , and :
+    let currpat = substitute(currpat, s:notslash .. '\zs\\\(:\|,\)', '\1', 'g')
     if a:0
       let alttail = strpart(alttail, j)
       let j = matchend(alttail, s:notslash .. a:comma)
@@ -621,7 +655,7 @@ fun! matchit#MultiMatch(spflag, mode)
     let default = escape(&mps, '[$^.*~\\/?]') .. (strlen(&mps) ? "," : "") ..
       \ '\/\*:\*\/,#\s*if\%(n\=def\)\=:#\s*else\>:#\s*elif\>:#\s*endif\>'
     let s:last_mps = &mps
-    let match_words = match_words .. (strlen(match_words) ? "," : "") .. default
+    let match_words = s:Append(match_words, default)
     let s:last_words = match_words
     if match_words !~ s:notslash .. '\\\d'
       let s:do_BR = 0

runtime/pack/dist/opt/matchit/doc/matchit.txt

@@ -1,13 +1,7 @@
-*matchit.txt*   Extended "%" matching
+*matchit.txt* Extended "%" matching  Last change: 2026 Jan 06
 
-For instructions on installing this file, type
-	`:help matchit-install`
-inside Vim.
+		VIM REFERENCE MANUAL    by Benji Fisher et al
 
-For Vim version 9.1.  Last change:  2024 May 20
-
-
-		  VIM REFERENCE MANUAL    by Benji Fisher et al
 
 *matchit* *matchit.vim*
 
@@ -174,7 +168,7 @@ defined automatically.
 
 2.1 Temporarily disable the matchit plugin	*matchit-disable* *:MatchDisable*
 
-To temporarily disable the matchit plugin, after it hat been loaded,
+To temporarily disable the matchit plugin, after it has been loaded,
 execute this command: >
 	:MatchDisable
 
@@ -259,6 +253,45 @@ Examples:
 	See the $VIMRUNTIME/ftplugin/vim.vim for an example that uses both
 	syntax and a regular expression.
 
+						*b:match_function*
+If b:match_function is defined, matchit.vim will first call this function to
+perform matching.  This is useful for languages with an indentation-based block
+structure (such as Python) or other complex matching requirements that cannot
+be expressed with regular expression patterns.
+
+The function should accept one argument:
+	forward - 1 for forward search (% command)
+	          0 for backward search (g% command)
+
+The function should return a list with one of these values:
+	[line, col]  - Match found at the specified position
+	[]           - No match found; fall through to regular matching
+	               (|b:match_words|, matchpairs, etc.)
+
+The cursor position is not changed by the function; matchit handles cursor
+movement based on the returned position.
+
+If the function throws an error, matchit gives up and doesn't continue.
+Enable |b:match_debug| to see error messages from custom match functions.
+
+Python example (simplified): >
+	let s:keywords = {'if': 'elif\|else', 'elif': 'elif\|else'}
+
+	function! s:PythonMatch(forward) abort
+	  let keyword = matchstr(getline('.'), '^\s*\zs\w\+')
+	  let pattern = get(s:keywords, keyword, '')
+	  if empty(pattern) | return [] | endif
+
+	  let flags = a:forward ? 'nW' : 'nbW'
+	  let [lnum, col] = searchpos('^\s*\%(' . pattern . '\)\>', flags, 0, 0,
+	  \                            'indent(".") != ' . indent('.'))
+	  return lnum > 0 ? [lnum, col] : []
+	endfunction
+
+	let b:match_function = function('s:PythonMatch')
+<
+See |matchit-newlang| below for more details on supporting new languages.
+
 ==============================================================================
 4. Supporting a New Language				*matchit-newlang*
 							*b:match_words*
@@ -270,9 +303,9 @@ Vim's |regular-expression|s.
 
 The format for |b:match_words| is similar to that of the 'matchpairs' option:
 it is a comma (,)-separated list of groups; each group is a colon(:)-separated
-list of patterns (regular expressions).  Commas and backslashes that are part
-of a pattern should be escaped with backslashes ('\:' and '\,').  It is OK to
-have only one group; the effect is undefined if a group has only one pattern.
+list of patterns (regular expressions).  Commas and colons that are part of a
+pattern should be escaped with backslashes ('\:' and '\,').  It is OK to have
+only one group; the effect is undefined if a group has only one pattern.
 A simple example is >
 	:let b:match_words = '\<if\>:\<endif\>,'
 		\ . '\<while\>:\<continue\>:\<break\>:\<endwhile\>'
@@ -315,7 +348,7 @@ expression >
 if keywords are only recognized after the start of a line or after a
 semicolon (;), with optional white space.
 
-					*matchit-backref* *matchit-\1*
+						*matchit-backref*
 In any group, the expressions |\1|, |\2|, ..., |\9| refer to parts of the
 INITIAL pattern enclosed in |\(|escaped parentheses|\)|.  These are referred
 to as back references, or backrefs.  For example, >

runtime/pack/dist/opt/matchit/doc/tags

@@ -6,6 +6,7 @@ MatchError	matchit.txt	/*MatchError*
 ]%	matchit.txt	/*]%*
 b:match_col	matchit.txt	/*b:match_col*
 b:match_debug	matchit.txt	/*b:match_debug*
+b:match_function	matchit.txt	/*b:match_function*
 b:match_ignorecase	matchit.txt	/*b:match_ignorecase*
 b:match_ini	matchit.txt	/*b:match_ini*
 b:match_iniBR	matchit.txt	/*b:match_iniBR*
@@ -20,7 +21,6 @@ b:match_words	matchit.txt	/*b:match_words*
 g%	matchit.txt	/*g%*
 matchit	matchit.txt	/*matchit*
 matchit-%	matchit.txt	/*matchit-%*
-matchit-\1	matchit.txt	/*matchit-\\1*
 matchit-activate	matchit.txt	/*matchit-activate*
 matchit-backref	matchit.txt	/*matchit-backref*
 matchit-bugs	matchit.txt	/*matchit-bugs*

runtime/pack/dist/opt/matchit/plugin/matchit.vim

@@ -1,6 +1,6 @@
 "  matchit.vim: (global plugin) Extended "%" matching
 "  Maintainer:  Christian Brabandt
-"  Version:     1.20
+"  Version:     1.21
 "  Last Change: 2024 May 20
 "  Repository:  https://github.com/chrisbra/matchit
 "  Previous URL:http://www.vim.org/script.php?script_id=39