From 2c8f3c6e9a8647c59e05fca2d1e69bb5c8393ff2 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Sat, 4 Sep 2021 22:29:10 -0400
Subject: [PATCH] Avoid infinite loop with self-referential rules

---
 lib/imbecile/parser/item_set.rb | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/imbecile/parser/item_set.rb b/lib/imbecile/parser/item_set.rb
index 0c7515a..619c222 100644
--- a/lib/imbecile/parser/item_set.rb
+++ b/lib/imbecile/parser/item_set.rb
@@ -44,7 +44,11 @@ class Imbecile
           this_eval_items = eval_items
           eval_items = Set.new
           this_eval_items.each do |item|
-            eval_items += item.closed_items
+            item.closed_items.each do |new_item|
+              unless @items.include?(new_item)
+                eval_items << new_item
+              end
+            end
           end
           @items += eval_items
         end