40 lines
1.3 KiB
Rust
40 lines
1.3 KiB
Rust
|
//! This module encapsulates some logic for upvalue handling, which is
|
||
|
|
//! relevant to both thunks (delayed computations for lazy-evaluation)
|
||
|
|
//! as well as closures (lambdas that capture variables from the
|
||
|
|
//! surrounding scope).
|
||
|
|
|
||
|
|
use std::cell::{Ref, RefMut};
|
||
|
|
|
||
|
|
use crate::{opcode::UpvalueIdx, Value};
|
||
|
|
|
||
|
|
/// `UpvalueCarrier` is implemented by all types that carry upvalues.
|
||
|
|
pub trait UpvalueCarrier {
|
||
|
|
fn upvalue_count(&self) -> usize;
|
||
|
|
|
||
|
|
/// Read-only accessor for the stored upvalues.
|
||
|
|
fn upvalues(&self) -> Ref<'_, [Value]>;
|
||
|
|
|
||
|
|
/// Mutable accessor for stored upvalues.
|
||
|
|
fn upvalues_mut(&self) -> RefMut<'_, Vec<Value>>;
|
||
|
|
|
||
|
|
/// Read an upvalue at the given index.
|
||
|
|
fn upvalue(&self, idx: UpvalueIdx) -> Ref<'_, Value> {
|
||
|
|
Ref::map(self.upvalues(), |v| &v[idx.0])
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Push an upvalue at the end of the upvalue list.
|
||
|
|
fn push_upvalue(&self, value: Value) {
|
||
|
|
self.upvalues_mut().push(value);
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Resolve deferred upvalues from the provided stack slice,
|
||
|
|
/// mutating them in the internal upvalue slots.
|
||
|
|
fn resolve_deferred_upvalues(&self, stack: &[Value]) {
|
||
|
|
for upvalue in self.upvalues_mut().iter_mut() {
|
||
|
|
if let Value::DeferredUpvalue(idx) = upvalue {
|
||
|
|
*upvalue = stack[idx.0].clone();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|