From a709ca8240d4ecd960f282bd3b64ab6256684f41 Mon Sep 17 00:00:00 2001
From: Eman Resu <78693624+quatquatt@users.noreply.github.com>
Date: Sat, 16 May 2026 00:29:39 -0400
Subject: [PATCH] lib.strings.splitString: compute escaped separator early

Thanks to moving the existing let variable out, this should have
identical performance for non-memoised calls, and improved performance
when caching the separator.
---
 lib/strings.nix | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/strings.nix b/lib/strings.nix
index 53dc515ac3f8..5425a4a66590 100644
--- a/lib/strings.nix
+++ b/lib/strings.nix
@@ -1740,11 +1740,11 @@ rec {
     :::
   */
   splitString =
-    sep: s:
+    sep:
     let
-      splits = filter isString (split (escapeRegex (toString sep)) (toString s));
+      escapedSep = escapeRegex (toString sep);
     in
-    map (addContextFrom s) splits;
+    s: map (addContextFrom s) (filter isString (split escapedSep (toString s)));
 
   /**
     Splits a string into substrings based on a predicate that examines adjacent characters.