tvl-depot/tvix/eval/src/value/function.rs
Vincent Ambo d75b207a63 refactor(tvix/eval): introduce Upvalues struct in closures & thunks
This struct will be responsible for tracking upvalues (and is a
convenient place to introduce optimisations for reducing value clones)
instead of a plain value vector.

The main motivation for this is that the upvalues will have to capture
the `with`-stack fully and I want to avoid duplicating the logic for
this between the two capturing types.

Change-Id: I6654f8739fc2e04ca046e6667d4a015f51724e99
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6485
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:16:46 +00:00

72 lines
1.5 KiB
Rust

//! This module implements the runtime representation of functions.
use std::{
cell::{Ref, RefCell, RefMut},
rc::Rc,
};
use crate::{
chunk::Chunk,
upvalues::{UpvalueCarrier, Upvalues},
};
#[derive(Clone, Debug)]
pub struct Lambda {
// name: Option<NixString>,
pub(crate) chunk: Chunk,
pub(crate) upvalue_count: usize,
}
impl Lambda {
pub fn new_anonymous() -> Self {
Lambda {
// name: None,
chunk: Default::default(),
upvalue_count: 0,
}
}
pub fn chunk(&mut self) -> &mut Chunk {
&mut self.chunk
}
}
#[derive(Clone, Debug)]
pub struct InnerClosure {
pub lambda: Rc<Lambda>,
upvalues: Upvalues,
}
#[repr(transparent)]
#[derive(Clone, Debug)]
pub struct Closure(Rc<RefCell<InnerClosure>>);
impl Closure {
pub fn new(lambda: Rc<Lambda>) -> Self {
Closure(Rc::new(RefCell::new(InnerClosure {
upvalues: Upvalues::with_capacity(lambda.upvalue_count),
lambda,
})))
}
pub fn chunk(&self) -> Ref<'_, Chunk> {
Ref::map(self.0.borrow(), |c| &c.lambda.chunk)
}
pub fn lambda(&self) -> Rc<Lambda> {
self.0.borrow().lambda.clone()
}
}
impl UpvalueCarrier for Closure {
fn upvalue_count(&self) -> usize {
self.0.borrow().lambda.upvalue_count
}
fn upvalues(&self) -> Ref<'_, Upvalues> {
Ref::map(self.0.borrow(), |c| &c.upvalues)
}
fn upvalues_mut(&self) -> RefMut<'_, Upvalues> {
RefMut::map(self.0.borrow_mut(), |c| &mut c.upvalues)
}
}