From 58351e44283ebaf4fa49c4ec1e50754f6ec9ed5e Mon Sep 17 00:00:00 2001
From: NAHO <90870942+trueNAHO@users.noreply.github.com>
Date: Mon, 16 Sep 2024 15:18:48 +0200
Subject: [PATCH] lib: eachSystem: optimize hot path by assuming rare --impure
 usage

---
 lib.nix | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/lib.nix b/lib.nix
index 8afb841..c7a74e8 100644
--- a/lib.nix
+++ b/lib.nix
@@ -48,17 +48,13 @@ let
       )
       { }
       (
-        systems
-        ++
+        if
+          !builtins ? currentSystem || builtins.elem builtins.currentSystem systems
+        then
+          systems
+        else
           # Add the current system if the --impure flag is used.
-          (
-            if
-              builtins ? currentSystem && !builtins.elem builtins.currentSystem systems
-            then
-              [ builtins.currentSystem ]
-            else
-              [ ]
-          )
+          systems ++ [ builtins.currentSystem ]
       );
 
   # eachSystemMap using defaultSystems