From 8034f71a5e72da3a7a62454193d7a2c914859e64 Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby.or.jp>
Date: Tue, 2 Sep 2025 22:53:21 +0900
Subject: [PATCH] mruby-compiler: replace NODE_LITERAL_DELIM with (0 . 0)
 pattern

NODE_LITERAL_DELIM was only used as a marker in literal arrays.
Replace it with a (0 . 0) pattern which cannot conflict with
empty strings (which would be (0 . ptr) with non-NULL ptr).
This allows removing NODE_LITERAL_DELIM from the node type enum.

Co-authored-by: Claude <noreply@anthropic.com>
---
 mrbgems/mruby-compiler/core/codegen.c | 4 ++--
 mrbgems/mruby-compiler/core/node.h    | 1 -
 mrbgems/mruby-compiler/core/parse.y   | 6 +-----
 3 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/mrbgems/mruby-compiler/core/codegen.c b/mrbgems/mruby-compiler/core/codegen.c
index 5ac30cf25..6c98e1426 100644
--- a/mrbgems/mruby-compiler/core/codegen.c
+++ b/mrbgems/mruby-compiler/core/codegen.c
@@ -68,10 +68,10 @@
 /* Maximum number of arguments for some opcodes like OP_SUPER or OP_ARGARY. */
 #define MAXARG_S (1<<16)
 
-/* Macro to detect NODE_LITERAL_DELIM separators in literal arrays */
+/* Macro to detect (0 . 0) separators in literal arrays */
 #define IS_LITERAL_DELIM(node) \
   ((node) && (node)->car && \
-   node_to_int((node)->car->car) == NODE_LITERAL_DELIM && \
+   (node)->car->car == NULL && \
    (node)->car->cdr == NULL)
 
 typedef mrb_ast_node node;
diff --git a/mrbgems/mruby-compiler/core/node.h b/mrbgems/mruby-compiler/core/node.h
index 231d4a577..061e7aa6a 100644
--- a/mrbgems/mruby-compiler/core/node.h
+++ b/mrbgems/mruby-compiler/core/node.h
@@ -88,7 +88,6 @@ enum node_type {
   NODE_POSTEXE,
   NODE_DSYM,
   NODE_HEREDOC,
-  NODE_LITERAL_DELIM,
   NODE_WORDS,
   NODE_SYMBOLS,
   NODE_VARIABLE,
diff --git a/mrbgems/mruby-compiler/core/parse.y b/mrbgems/mruby-compiler/core/parse.y
index d7fe602a8..2e6da10bd 100644
--- a/mrbgems/mruby-compiler/core/parse.y
+++ b/mrbgems/mruby-compiler/core/parse.y
@@ -2270,7 +2270,7 @@ new_bv(parser_state *p, mrb_sym id)
 static node*
 new_literal_delim(parser_state *p)
 {
-  return cons_head((node*)NODE_LITERAL_DELIM, 0);
+  return cons((node*)0, (node*)0);
 }
 
 /* (:words . a) */
@@ -8781,10 +8781,6 @@ mrb_parser_dump(mrb_state *mrb, node *tree, int offset)
     dump_recur(mrb, tree, offset+1);
     break;
 
-  case NODE_LITERAL_DELIM:
-    printf("NODE_LITERAL_DELIM\n");
-    break;
-
   case NODE_SELF:
     printf("NODE_SELF\n");
     break;