refactor(tvix/eval): Box Value::String r/7467

NixString is *quite* large - like 80 bytes - because of the extra
capacity value for BString and because of the context. We want to keep
Value small since we're passing it around a lot, so let's box the
NixString inside Value::String to save on some memory, and make cloning
ostensibly a little cheaper

Change-Id: I343c8b4e7f61dc3dcbbaba4382efb3b3e5bbabb2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10729
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/tvix/serde/src/de.rs b/tvix/serde/src/de.rs
index cf85ffab2e81..6a020c978f64 100644
--- a/tvix/serde/src/de.rs
+++ b/tvix/serde/src/de.rs
@@ -347,7 +347,7 @@ impl<'de> de::Deserializer<'de> for NixDeserializer {
         if let Value::Attrs(attrs) = self.value {
             let mut map = MapDeserializer::new(attrs.into_iter().map(|(k, v)| {
                 (
-                    NixDeserializer::new(Value::String(k)),
+                    NixDeserializer::new(Value::from(k)),
                     NixDeserializer::new(v),
                 )
             }));