From bd8890563ef64bbb96baf5cffd727e81d90226b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9ophane=20Hufschmitt?=
 <theophane.hufschmitt@tweag.io>
Date: Wed, 26 Jun 2024 15:29:05 +0200
Subject: [PATCH] Flatten the Nix strings on the fly

Reduces the size of the generated json by ~300%, and causes a ~1.6x
speedup in the Nickel evaluation time
---
 lib/nix-interop/derivation.ncl | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/nix-interop/derivation.ncl b/lib/nix-interop/derivation.ncl
index 5ff6978..d9b1717 100644
--- a/lib/nix-interop/derivation.ncl
+++ b/lib/nix-interop/derivation.ncl
@@ -168,7 +168,12 @@ in
         mk_nix_string [value]
       else
         let { fragments, .. } = std.contract.apply NixSymbolicString label value in
-        mk_nix_string fragments,
+        mk_nix_string
+          (
+            std.array.flat_map
+              (fun elt => elt.fragments)
+              fragments
+          ),
 
   NixDerivation
     | doc m%"