feat: support modelines

README.md

@@ -50,11 +50,11 @@ Known issues
 - `column_heading` currently only recognizes tilde `~` preceded by space (i.e.
   `foo ~` not `foo~`). This covers 99% of :help files.
 - `column_heading` children should be plaintext, but currently are parsed as `$._atom`.
+- `modeline` must be preceded by a blank line.
 
 TODO
 ----
 
-- `line_modeline` ?
 - `tag_heading` : line(s) containing only tags, typically implies a "heading"
   before a block.
 

grammar.js

@@ -26,6 +26,7 @@ module.exports = grammar({
       seq(
         repeat($._blank),  // Eat blank lines at top of file.
         repeat($.block),
+        repeat($.modeline),
       ),
 
     _atom: ($) => choice(
@@ -169,6 +170,9 @@ module.exports = grammar({
       choice($.codeblock, '\n')
     ),
 
+    // Modeline: must start with "vim:" (optionally preceded by whitespace)
+    modeline: ($) => token(prec(2, /[\t ]*vim:[^\n]+\n/)),
+
     // "Column heading": plaintext followed by "~".
     // Intended for table column names per `:help help-writing`.
     // TODO: children should be $.word (plaintext), not $.atom.

queries/vimdoc/highlights.scm

@@ -48,6 +48,8 @@
 
 (url) @string.special.url
 
+(modeline) @keyword.directive
+
 ((note) @comment.hint
   (#any-of? @comment.hint "Note:" "NOTE:" "Notes:"))