refactor(tvix/eval): Builderize Evaluation r/8351

Make constructing of a new Evaluation use the builder pattern rather
than setting public mutable fields. This is currently a pure
refactor (no functionality has changed) but has a few advantages:

- We've encapsulated the internals of the fields in Evaluation, meaning
  we can change them without too much breakage of clients
- We have type safety that prevents us from ever changing the fields of
  an Evaluation after it's built (which matters more in a world where we
  reuse Evaluations).

More importantly, this paves the road for doing different things with
the construction of an Evaluation - notably, sharing certain things like
the GlobalsMap across subsequent evaluations in eg the REPL.

Fixes: b/262
Change-Id: I4a27116faac14cdd144fc7c992d14ae095a1aca4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11956
Tested-by: BuildkiteCI
Autosubmit: aspen <root@gws.fyi>
Reviewed-by: flokli <flokli@flokli.de>

1 files changed, 6 insertions, 4 deletions

diff --git a/tvix/glue/src/tvix_store_io.rs b/tvix/glue/src/tvix_store_io.rs
index 4e5488067f8f..e8c09af0ec4c 100644
--- a/tvix/glue/src/tvix_store_io.rs
+++ b/tvix/glue/src/tvix_store_io.rs
@@ -653,11 +653,13 @@ mod tests {
             Arc::<DummyBuildService>::default(),
             tokio_runtime.handle().clone(),
         ));
-        let mut eval = tvix_eval::Evaluation::new(io.clone() as Rc<dyn EvalIO>, true);
 
-        add_derivation_builtins(&mut eval, io.clone());
-        add_fetcher_builtins(&mut eval, io.clone());
-        add_import_builtins(&mut eval, io);
+        let mut eval_builder =
+            tvix_eval::Evaluation::builder(io.clone() as Rc<dyn EvalIO>).enable_import();
+        eval_builder = add_derivation_builtins(eval_builder, Rc::clone(&io));
+        eval_builder = add_fetcher_builtins(eval_builder, Rc::clone(&io));
+        eval_builder = add_import_builtins(eval_builder, io);
+        let eval = eval_builder.build();
 
         // run the evaluation itself.
         eval.evaluate(str, None)