37 lines
1.2 KiB
Rust
37 lines
1.2 KiB
Rust
|
//! 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 {}
|