diff options
author | Vincent Ambo <mail@tazj.in> | 2022-09-04T13·51+0300 |
---|---|---|
committer | tazjin <tazjin@tvl.su> | 2022-09-09T21·10+0000 |
commit | 7ae45342df28c7f3feb50334aee535a1d36e2bec (patch) | |
tree | 65f70ac724d987a6d4c107c03a72b4ac714a3020 /tvix/eval/src/observer.rs | |
parent | 1fe6cfe5a279cd19dbb2586f30db6a8790db7a4d (diff) |
feat(tvix/eval): implement (compilation) observer trait r/4774
This trait will enable library users of tvix-eval to observe internal happenings of the compilation and runtime processes. The initial methods of the observer will be called whenever the compiler emits a chunk. Change-Id: I668f6c2cfe3d6f4c1a1612c0f293831011768437 Reviewed-on: https://cl.tvl.fyi/c/depot/+/6448 Reviewed-by: sterni <sternenseemann@systemli.org> Tested-by: BuildkiteCI
Diffstat (limited to '')
-rw-r--r-- | tvix/eval/src/observer.rs | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/tvix/eval/src/observer.rs b/tvix/eval/src/observer.rs new file mode 100644 index 000000000000..bf05295ac356 --- /dev/null +++ b/tvix/eval/src/observer.rs @@ -0,0 +1,36 @@ +//! Implements a trait for things that wish to observe internal state +//! changes of tvix-eval. +//! +//! This can be used to gain insights from compilation, to trace the +//! runtime, and so on. + +use crate::value::Lambda; + +use std::rc::Rc; + +/// Implemented by types that wish to observe internal happenings of +/// Tvix. +/// +/// All methods are optional, that is, observers can implement only +/// what they are interested in observing. +pub trait Observer { + /// Called when the compiler finishes compilation of the top-level + /// of an expression (usually the root Nix expression of a file). + fn observe_compiled_toplevel(&mut self, _: &Rc<Lambda>) {} + + /// Called when the compiler finishes compilation of a + /// user-defined function. + /// + /// Note that in Nix there are only single argument functions, so + /// in an expression like `a: b: c: ...` this method will be + /// called three times. + fn observe_compiled_lambda(&mut self, _: &Rc<Lambda>) {} + + /// Called when the compiler finishes compilation of a thunk. + fn observe_compiled_thunk(&mut self, _: &Rc<Lambda>) {} +} + +#[derive(Default)] +pub struct NoOpObserver {} + +impl Observer for NoOpObserver {} |