From b9b64c35173b82d01dfc0c115744df9d613171a3 Mon Sep 17 00:00:00 2001
From: Max Horn <max@quendi.de>
Date: Thu, 29 Dec 2022 02:37:59 +0100
Subject: [PATCH] Make two-argument Remove faster.

Before:

    gap> l := List([1..100000], i->[i]);;
    gap> while Length(l)>0 do Remove(l,Length(l)); od; time;
    53937

After:

    gap> l := List([1..100000], i->[i]);;
    gap> while Length(l)>0 do Remove(l,Length(l)); od; time;
    17
---
 lib/list.gi | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/list.gi b/lib/list.gi
index 0adbd7345f..eb83455a0d 100644
--- a/lib/list.gi
+++ b/lib/list.gi
@@ -1984,9 +1984,12 @@ InstallMethod(Remove, "one argument", [IsList and IsMutable],
     return x;
 end);
 
-InstallMethod(Remove, "two arguments, fast", [IsList and IsPlistRep and IsMutable, IsPosInt],
+InstallEarlyMethod(Remove,
         function(l,p)
     local ret,x,len;
+    if not (IsPlistRep(l) and IsMutable(l) and IsPosInt(p)) then
+        TryNextMethod();
+    fi;
     len := Length(l);
     ret := IsBound(l[p]);
     if ret then