Relax ordering in 'select' cases

We shouldn't really care whether or not `default` *is* the last value...

grammar.js

@@ -154,23 +154,18 @@ module.exports = grammar({
     select_cases: ($) => seq(
       "{",
       optional(trailingCommaSeparated($.select_case)),
-      // default *must* be the last one, enforced at parse-time...
-      optional(seq(alias($.default_case, $.select_case), ",")),
       "}",
     ),
 
     select_case: ($) => seq(
-      field("pattern", $._string_literal),
+      field("pattern", choice(
+        $._string_literal,
+        alias("default", $.default),
+      )),
       ":",
       field("value", $._case_value)
     ),
 
-    default_case: ($) => seq(
-      field("pattern", alias("default", $.default)),
-      ":",
-      field("value", $._case_value),
-    ),
-
     _case_value: ($) => choice(
       alias("unset", $.unset),
       $._expr,

src/grammar.json

@@ -628,32 +628,6 @@
             }
           ]
         },
-        {
-          "type": "CHOICE",
-          "members": [
-            {
-              "type": "SEQ",
-              "members": [
-                {
-                  "type": "ALIAS",
-                  "content": {
-                    "type": "SYMBOL",
-                    "name": "default_case"
-                  },
-                  "named": true,
-                  "value": "select_case"
-                },
-                {
-                  "type": "STRING",
-                  "value": ","
-                }
-              ]
-            },
-            {
-              "type": "BLANK"
-            }
-          ]
-        },
         {
           "type": "STRING",
           "value": "}"
@@ -667,31 +641,13 @@
           "type": "FIELD",
           "name": "pattern",
           "content": {
-            "type": "SYMBOL",
+            "type": "CHOICE",
-            "name": "_string_literal"
-          }
-        },
-        {
-          "type": "STRING",
-          "value": ":"
-        },
-        {
-          "type": "FIELD",
-          "name": "value",
-          "content": {
-            "type": "SYMBOL",
-            "name": "_case_value"
-          }
-        }
-      ]
-    },
-    "default_case": {
-      "type": "SEQ",
             "members": [
               {
-          "type": "FIELD",
+                "type": "SYMBOL",
-          "name": "pattern",
+                "name": "_string_literal"
-          "content": {
+              },
+              {
                 "type": "ALIAS",
                 "content": {
                   "type": "STRING",
@@ -700,6 +656,8 @@
                 "named": true,
                 "value": "default"
               }
+            ]
+          }
         },
         {
           "type": "STRING",

test/corpus/select.txt

@@ -135,10 +135,9 @@ foo = select(variant("VARIANT"), {
         (select_case
           (interpreted_string_literal)
           (interpreted_string_literal))
-        (ERROR
         (select_case
           (default)
-            (unset)))
+          (unset))
         (select_case
           (interpreted_string_literal)
           (interpreted_string_literal))