Parse bracket comment using external scanner

- Due to bracket comment has to have the pattern /[=*[/ follow '#'
  symbol immediately, it's easier to implement it using external scanner

grammar.js

@@ -79,7 +79,7 @@ message_args = [
 module.exports = grammar({
   name: "cmake",
 
-  externals: ($) => [$.bracket_argument],
+  externals: ($) => [$.bracket_argument, $.bracket_comment],
   extras: ($) => [/[\s\n\r]/, $.comment],
 
   rules: {
@@ -141,7 +141,7 @@ module.exports = grammar({
         $.message_command
       ),
 
-    comment: ($) => seq("#", choice($.bracket_argument)),
+    comment: ($) => choice($.bracket_comment),
 
     ...commandNames(...commands),
     identifier: (_) => /[A-Za-z_][A-Za-z0-9_]*/,

src/grammar.json

@@ -1911,20 +1911,11 @@
       ]
     },
     "comment": {
-      "type": "SEQ",
-      "members": [
-        {
-          "type": "STRING",
-          "value": "#"
-        },
-        {
       "type": "CHOICE",
       "members": [
         {
           "type": "SYMBOL",
-              "name": "bracket_argument"
-            }
-          ]
+          "name": "bracket_comment"
         }
       ]
     },
@@ -2005,6 +1996,10 @@
     {
       "type": "SYMBOL",
       "name": "bracket_argument"
+    },
+    {
+      "type": "SYMBOL",
+      "name": "bracket_comment"
     }
   ],
   "inline": [],

src/node-types.json

@@ -46,7 +46,7 @@
       "required": true,
       "types": [
         {
-          "type": "bracket_argument",
+          "type": "bracket_comment",
           "named": true
         }
       ]
@@ -730,10 +730,6 @@
     "type": "\"",
     "named": false
   },
-  {
-    "type": "#",
-    "named": false
-  },
   {
     "type": "$CACHE",
     "named": false
@@ -1018,6 +1014,10 @@
     "type": "bracket_argument",
     "named": true
   },
+  {
+    "type": "bracket_comment",
+    "named": true
+  },
   {
     "type": "else",
     "named": true

src/scanner.cc

@@ -3,16 +3,19 @@
 #include <tree_sitter/parser.h>
 
 namespace {
-enum TokenType { BRACKET_ARGUMENT, LINE_COMMENT };
+enum TokenType { BRACKET_ARGUMENT, BRACKET_COMMENT };
 void skip(TSLexer *lexer) { lexer->advance(lexer, true); }
 void advance(TSLexer *lexer) { lexer->advance(lexer, false); }
-bool scan_bracket_argument(TSLexer *lexer) {
-  while (std::iswspace(lexer->lookahead))
+bool scan_bracket_argument(TSLexer *lexer, bool skip_wspace) {
+  if (skip_wspace) {
+    while (std::iswspace(lexer->lookahead)) {
       skip(lexer);
+    }
+  }
 
-  if (lexer->lookahead != '[')
+  if (lexer->lookahead != '[') {
     return false;
-
+  }
   advance(lexer);
 
   int open_level = 0;
@@ -21,8 +24,9 @@ bool scan_bracket_argument(TSLexer *lexer) {
     advance(lexer);
   }
 
-  if (lexer->lookahead != '[')
+  if (lexer->lookahead != '[') {
     return false;
+  }
 
   while (lexer->lookahead != '\0') {
     advance(lexer);
@@ -44,9 +48,22 @@ bool scan_bracket_argument(TSLexer *lexer) {
   }
   return false;
 }
+bool scan_bracket_comment(TSLexer *lexer) {
+  if (lexer->lookahead != '#') {
+    return false;
+  }
+  advance(lexer);
+  if (scan_bracket_argument(lexer, false)) {
+    lexer->result_symbol = BRACKET_COMMENT;
+    return true;
+  }
+  return false;
+}
 bool scan(void *payload, TSLexer *lexer, const bool *valid_symbols) {
   if (valid_symbols[BRACKET_ARGUMENT])
-    return scan_bracket_argument(lexer);
+    return scan_bracket_argument(lexer, true);
+  if (valid_symbols[BRACKET_ARGUMENT])
+    return scan_bracket_comment(lexer);
 
   return false;
 }