Expose brackets and template tag name

Some editor features requires the abillity to capture the brackets
independent from the tag name. e.g. Zed captures `<` as brackets and
highlight them different from the tag name. It uses it to highlight the
opposite opening/closing pair when the cursor is on one of the brackets.

Author: mogstad

grammar.js

@@ -10,22 +10,22 @@ function noJSX(obj) {
     return;
   }
 
-  if (typeof obj === 'object') {
+  if (typeof obj === "object") {
     if (obj === null) return;
 
-    if (obj.type === 'CHOICE' && Array.isArray(obj.members)) {
-      obj.members = obj.members.filter(member => {
+    if (obj.type === "CHOICE" && Array.isArray(obj.members)) {
+      obj.members = obj.members.filter((member) => {
         if (!member.name) return true;
 
-        return !member.name.includes('jsx');
+        return !member.name.includes("jsx");
       });
 
       noJSX(obj.members);
       return;
     }
 
     for (let [key, value] of Object.entries(obj)) {
-      if (key.includes('jsx')) {
+      if (key.includes("jsx")) {
         delete obj[key];
       } else {
         noJSX(value);
@@ -62,15 +62,15 @@ module.exports = grammar(JavaScript, {
      *         https://github.com/emberjs/rfcs/
      */
     glimmer_template: ($) =>
-        seq(
-          field("open_tag", $.glimmer_opening_tag),
-          optional(alias(repeat($._glimmer_template_content), $.raw_text)),
-          field("close_tag", $.glimmer_closing_tag),
-        ),
+      seq(
+        field("open_tag", $.glimmer_opening_tag),
+        optional($.raw_text),
+        field("close_tag", $.glimmer_closing_tag),
+      ),
 
-    _glimmer_template_content: (_) => /.{1,}/,
-    glimmer_opening_tag: (_) => "<template>",
-    glimmer_closing_tag: (_) => "</template>",
+    glimmer_opening_tag: ($) => seq("<", $.glimmer_template_tag_name, ">"),
+    glimmer_closing_tag: ($) => seq("</", $.glimmer_template_tag_name, ">"),
+    glimmer_template_tag_name: (_) => "template",
 
     /**
      * 2. Any Expression.

src/grammar.json

@@ -2409,16 +2409,8 @@
           "type": "CHOICE",
           "members": [
             {
-              "type": "ALIAS",
-              "content": {
-                "type": "REPEAT",
-                "content": {
-                  "type": "SYMBOL",
-                  "name": "_glimmer_template_content"
-                }
-              },
-              "named": true,
-              "value": "raw_text"
+              "type": "SYMBOL",
+              "name": "raw_text"
             },
             {
               "type": "BLANK"
@@ -2440,12 +2432,38 @@
       "value": ".{1,}"
     },
     "glimmer_opening_tag": {
-      "type": "STRING",
-      "value": "<template>"
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "<"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "glimmer_template_tag_name"
+        },
+        {
+          "type": "STRING",
+          "value": ">"
+        }
+      ]
     },
     "glimmer_closing_tag": {
-      "type": "STRING",
-      "value": "</template>"
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "</"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "glimmer_template_tag_name"
+        },
+        {
+          "type": "STRING",
+          "value": ">"
+        }
+      ]
     },
     "html_character_reference": {
       "type": "PATTERN",
@@ -6221,6 +6239,10 @@
           "value": ";"
         }
       ]
+    },
+    "glimmer_template_tag_name": {
+      "type": "STRING",
+      "value": "template"
     }
   },
   "extras": [

src/node-types.json

@@ -1616,6 +1616,36 @@
       }
     }
   },
+  {
+    "type": "glimmer_closing_tag",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": false,
+      "required": true,
+      "types": [
+        {
+          "type": "glimmer_template_tag_name",
+          "named": true
+        }
+      ]
+    }
+  },
+  {
+    "type": "glimmer_opening_tag",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": false,
+      "required": true,
+      "types": [
+        {
+          "type": "glimmer_template_tag_name",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "glimmer_template",
     "named": true,
@@ -2252,11 +2282,6 @@
       ]
     }
   },
-  {
-    "type": "raw_text",
-    "named": true,
-    "fields": {}
-  },
   {
     "type": "regex",
     "named": true,
@@ -2989,6 +3014,10 @@
     "type": "<",
     "named": false
   },
+  {
+    "type": "</",
+    "named": false
+  },
   {
     "type": "<<",
     "named": false
@@ -3174,11 +3203,7 @@
     "named": false
   },
   {
-    "type": "glimmer_closing_tag",
-    "named": true
-  },
-  {
-    "type": "glimmer_opening_tag",
+    "type": "glimmer_template_tag_name",
     "named": true
   },
   {
@@ -3245,6 +3270,10 @@
     "type": "property_identifier",
     "named": true
   },
+  {
+    "type": "raw_text",
+    "named": true
+  },
   {
     "type": "regex_flags",
     "named": true