bjoernager/rust
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Remove vec_linked_list.

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It provides a way to effectively embed a linked list within an
`IndexVec` and also iterate over that list. It's written in a very
generic way, involving two traits `Links` and `LinkElem`. But the
`Links` trait is only impl'd for `IndexVec` and `&IndexVec`, and the
whole thing is only used in one module within `rustc_borrowck`. So I
think it's over-engineered and hard to read. Plus it has no comments.

This commit removes it, and adds a (non-generic) local iterator for the
use within `rustc_borrowck`. Much simpler.
This commit is contained in:
Nicholas Nethercote 2024-05-07 09:35:50 +10:00
parent f5d7d346a4
commit d3d01e1cd3
3 changed files with 32 additions and 81 deletions
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1
compiler/rustc_data_structures/src/lib.rs
View file

@ -85,7 +85,6 @@ pub mod temp_dir;
pub mod transitive_relation;
pub mod unhash;
pub mod unord;
pub mod vec_linked_list;
pub mod work_queue;
mod atomic_ref;

70
compiler/rustc_data_structures/src/vec_linked_list.rs
View file

@ -1,70 +0,0 @@
use rustc_index::{Idx, IndexVec};
pub fn iter<Ls>(
first: Option<Ls::LinkIndex>,
links: &Ls,
) -> impl Iterator<Item = Ls::LinkIndex> + '_
where
Ls: Links,
{
VecLinkedListIterator { links, current: first }
}
pub struct VecLinkedListIterator<Ls>
where
Ls: Links,
{
links: Ls,
current: Option<Ls::LinkIndex>,
}
impl<Ls> Iterator for VecLinkedListIterator<Ls>
where
Ls: Links,
{
type Item = Ls::LinkIndex;
fn next(&mut self) -> Option<Ls::LinkIndex> {
if let Some(c) = self.current {
self.current = <Ls as Links>::next(&self.links, c);
Some(c)
} else {
None
}
}
}
pub trait Links {
type LinkIndex: Copy;
fn next(links: &Self, index: Self::LinkIndex) -> Option<Self::LinkIndex>;
}
impl<Ls> Links for &Ls
where
Ls: Links,
{
type LinkIndex = Ls::LinkIndex;
fn next(links: &Self, index: Ls::LinkIndex) -> Option<Ls::LinkIndex> {
<Ls as Links>::next(links, index)
}
}
pub trait LinkElem {
type LinkIndex: Copy;
fn next(elem: &Self) -> Option<Self::LinkIndex>;
}
impl<L, E> Links for IndexVec<L, E>
where
E: LinkElem<LinkIndex = L>,
L: Idx,
{
type LinkIndex = L;
fn next(links: &Self, index: L) -> Option<L> {
<E as LinkElem>::next(&links[index])
}
}