Support [] interpolation in new parser

src/parser2.ts

@@ -147,6 +147,14 @@ class Parser {
           wip.addWordPiece({ bare: chars }, pos);
           break;
 
+        case "[": {
+          this.advance();
+          const script = this.parseScript();
+          wip.addWordPiece({ script });
+          this.expect("]");
+          break;
+        }
+
         case "whitespace":
           wip.finishWord();
           break;
@@ -162,7 +170,6 @@ class Parser {
 
         case "{":
         case "}":
-        case "[":
         case "quote":
         case "backslash":
         case "comment":