From a9124292c8e90072bcada0b6461ef76e7ca85467 Mon Sep 17 00:00:00 2001
From: Devin Yeung <devin.cg.yeung.dev@outlook.com>
Date: Fri, 17 Nov 2023 21:52:31 +0800
Subject: [PATCH] fix: fix change detection in `first`

---
 src/utils/first.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/utils/first.rs b/src/utils/first.rs
index ca89ff2..021827e 100644
--- a/src/utils/first.rs
+++ b/src/utils/first.rs
@@ -60,7 +60,7 @@ impl<'grammar> First<'grammar> {
                             .filter(|term| term != &&Term::Terminal("ε".to_string()))
                         {
                             // First(Y1) ∖ {ε} to First(X)
-                            changed = builder.insert_first_no_epsilon(&production.lhs, term);
+                            changed |= builder.insert_first_no_epsilon(&production.lhs, term);
                             println!(
                                 "Rule3/4: Push First({}) \\ ε to First({})",
                                 term,