From f975f2eec08710a1e28e029cf47ffb9b9911228e Mon Sep 17 00:00:00 2001
From: Ziyang Hu <hu.ziyang@cantab.net>
Date: Fri, 20 Jan 2023 19:30:48 +0800
Subject: [PATCH] forbid unregister default rules

---
 cozo-core/src/runtime/db.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cozo-core/src/runtime/db.rs b/cozo-core/src/runtime/db.rs
index 0cda3eb7..4838e3a8 100644
--- a/cozo-core/src/runtime/db.rs
+++ b/cozo-core/src/runtime/db.rs
@@ -699,7 +699,7 @@ impl<'s, S: Storage<'s>> Db<S> {
 
     /// Unregister a custom fixed rule implementation.
     pub fn unregister_fixed_rule(&self, name: &str) -> Result<bool> {
-        if "Constant" == name {
+        if DEFAULT_FIXED_RULES.contains_key(name) {
             bail!("Cannot unregister builtin fixed rule {}", name);
         }
         Ok(self.fixed_rules.write().unwrap().remove(name).is_some())