diff options
| -rw-r--r-- | tvix/eval/src/lib.rs | 1 | ||||
| -rw-r--r-- | tvix/eval/src/observer.rs | 36 |
2 files changed, 37 insertions, 0 deletions
diff --git a/tvix/eval/src/lib.rs b/tvix/eval/src/lib.rs index 7156a03b6444..e088ef3ee4e3 100644 --- a/tvix/eval/src/lib.rs +++ b/tvix/eval/src/lib.rs @@ -3,6 +3,7 @@ mod chunk; mod compiler; mod errors; mod eval; +mod observer; mod opcode; mod upvalues; mod value; 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 {} |