Improve AST

bindings/dust

@@ -1 +1 @@
-Subproject commit e9db34be8bf38f1d636ffac82e4bc3db5c727524
+Subproject commit 597d6bd8b8aed37512ef8b27a4e2d5dea52d7cad

examples/list.ds

@@ -1,4 +1,4 @@
-numbers = [1, 2 3]
+numbers = [1, 2, 3]
 
 x = numbers.0
 y = numbers.1

grammar.js

@@ -164,7 +164,7 @@ module.exports = grammar({
     function_call: $ => prec.right(seq(
       $.identifier,
       '<',
-      repeat($.expression),
+      repeat(seq($.expression, optional(','))),
       '>',
     )),
 

src/grammar.json

@@ -733,8 +733,25 @@
           {
             "type": "REPEAT",
             "content": {
-              "type": "SYMBOL",
+              "type": "SEQ",
-              "name": "expression"
+              "members": [
+                {
+                  "type": "SYMBOL",
+                  "name": "expression"
+                },
+                {
+                  "type": "CHOICE",
+                  "members": [
+                    {
+                      "type": "STRING",
+                      "value": ","
+                    },
+                    {
+                      "type": "BLANK"
+                    }
+                  ]
+                }
+              ]
             }
           },
           {