From 46e08442cd40fb33742594278a5554104cebcb31 Mon Sep 17 00:00:00 2001
From: Vasil Markoukin <susliko@users.noreply.github.com>
Date: Tue, 8 Aug 2023 18:38:19 +0300
Subject: [PATCH] Allow `$.stable_type_identifier` in `derives_clause` (#331)

Resolves #323

Summary
----
Support for dot-separated type references in derives clause
```scala
case class A() derives B.C
```
---
 corpus/definitions.txt | 6 ++++--
 grammar.js             | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/corpus/definitions.txt b/corpus/definitions.txt
index d741390e8..b8e1e54e1 100644
--- a/corpus/definitions.txt
+++ b/corpus/definitions.txt
@@ -502,7 +502,7 @@ class A
 ================================================================================
 Class definitions (Scala 3)
 ================================================================================
-final case class C() extends A derives B, C
+final case class C() extends A derives B, C.D
 --------------------------------------------------------------------------------
 
 (compilation_unit
@@ -514,7 +514,9 @@ final case class C() extends A derives B, C
       (type_identifier))
     (derives_clause
       (type_identifier)
-      (type_identifier))))
+      (stable_type_identifier
+        (identifier)
+        (type_identifier)))))
 
 ================================================================================
 Subclass definitions
diff --git a/grammar.js b/grammar.js
index dd6fb1d48..cd9416fb2 100644
--- a/grammar.js
+++ b/grammar.js
@@ -681,7 +681,7 @@ module.exports = grammar({
       ),
 
     derives_clause: $ =>
-      prec.left(seq("derives", commaSep1(field("type", $._type_identifier)))),
+      prec.left(seq("derives", commaSep1(field("type", choice($._type_identifier, $.stable_type_identifier))))),
 
     class_parameters: $ =>
       prec(