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, 3 insertions, 3 deletions

diff --git a/tvix/eval/src/compiler/mod.rs b/tvix/eval/src/compiler/mod.rs
index 0fa3d41393..4a7b5fd5ba 100644
--- a/tvix/eval/src/compiler/mod.rs
+++ b/tvix/eval/src/compiler/mod.rs
@@ -369,7 +369,7 @@ impl Compiler<'_> {
 
             ast::LiteralKind::Uri(u) => {
                 self.emit_warning(node, WarningKind::DeprecatedLiteralURL);
-                Value::String(u.syntax().text().into())
+                Value::from(u.syntax().text())
             }
         };
 
@@ -458,7 +458,7 @@ impl Compiler<'_> {
                 }
 
                 ast::InterpolPart::Literal(lit) => {
-                    self.emit_constant(Value::String(lit.as_str().into()), parent_node);
+                    self.emit_constant(Value::from(lit.as_str()), parent_node);
                 }
             }
         }
@@ -1360,7 +1360,7 @@ impl Compiler<'_> {
     /// several operations related to attribute sets, where
     /// identifiers are used as string keys.
     fn emit_literal_ident(&mut self, ident: &ast::Ident) {
-        self.emit_constant(Value::String(ident.clone().into()), ident);
+        self.emit_constant(Value::String(Box::new(ident.clone().into())), ident);
     }
 
     /// Patch the jump instruction at the given index, setting its