bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'lib/la-arena/src/map.rs')
-rw-r--r--lib/la-arena/src/map.rs70
1 files changed, 61 insertions, 9 deletions
diff --git a/lib/la-arena/src/map.rs b/lib/la-arena/src/map.rs
index 7fff2b09c9..750f345b53 100644
--- a/lib/la-arena/src/map.rs
+++ b/lib/la-arena/src/map.rs
@@ -1,3 +1,4 @@
+use std::iter::Enumerate;
use std::marker::PhantomData;
use crate::Idx;
@@ -72,17 +73,17 @@ impl<T, V> ArenaMap<Idx<T>, V> {
}
/// Returns an iterator over the values in the map.
- pub fn values(&self) -> impl Iterator<Item = &V> {
+ pub fn values(&self) -> impl Iterator<Item = &V> + DoubleEndedIterator {
self.v.iter().filter_map(|o| o.as_ref())
}
/// Returns an iterator over mutable references to the values in the map.
- pub fn values_mut(&mut self) -> impl Iterator<Item = &mut V> {
+ pub fn values_mut(&mut self) -> impl Iterator<Item = &mut V> + DoubleEndedIterator {
self.v.iter_mut().filter_map(|o| o.as_mut())
}
/// Returns an iterator over the arena indexes and values in the map.
- pub fn iter(&self) -> impl Iterator<Item = (Idx<T>, &V)> {
+ pub fn iter(&self) -> impl Iterator<Item = (Idx<T>, &V)> + DoubleEndedIterator {
self.v.iter().enumerate().filter_map(|(idx, o)| Some((Self::from_idx(idx), o.as_ref()?)))
}
@@ -94,12 +95,6 @@ impl<T, V> ArenaMap<Idx<T>, V> {
.filter_map(|(idx, o)| Some((Self::from_idx(idx), o.as_mut()?)))
}
- /// Returns an iterator over the arena indexes and values in the map.
- // FIXME: Implement `IntoIterator` trait.
- pub fn into_iter(self) -> impl Iterator<Item = (Idx<T>, V)> {
- self.v.into_iter().enumerate().filter_map(|(idx, o)| Some((Self::from_idx(idx), o?)))
- }
-
/// Gets the given key's corresponding entry in the map for in-place manipulation.
pub fn entry(&mut self, idx: Idx<T>) -> Entry<'_, Idx<T>, V> {
let idx = Self::to_idx(idx);
@@ -154,6 +149,63 @@ impl<T, V> FromIterator<(Idx<V>, T)> for ArenaMap<Idx<V>, T> {
}
}
+pub struct ArenaMapIter<IDX, V> {
+ iter: Enumerate<std::vec::IntoIter<Option<V>>>,
+ _ty: PhantomData<IDX>,
+}
+
+impl<T, V> IntoIterator for ArenaMap<Idx<T>, V> {
+ type Item = (Idx<T>, V);
+
+ type IntoIter = ArenaMapIter<Idx<T>, V>;
+
+ fn into_iter(self) -> Self::IntoIter {
+ let iter = self.v.into_iter().enumerate();
+ Self::IntoIter { iter, _ty: PhantomData }
+ }
+}
+
+impl<T, V> ArenaMapIter<Idx<T>, V> {
+ fn mapper((idx, o): (usize, Option<V>)) -> Option<(Idx<T>, V)> {
+ Some((ArenaMap::<Idx<T>, V>::from_idx(idx), o?))
+ }
+}
+
+impl<T, V> Iterator for ArenaMapIter<Idx<T>, V> {
+ type Item = (Idx<T>, V);
+
+ #[inline]
+ fn next(&mut self) -> Option<Self::Item> {
+ for next in self.iter.by_ref() {
+ match Self::mapper(next) {
+ Some(r) => return Some(r),
+ None => continue,
+ }
+ }
+
+ None
+ }
+
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.iter.size_hint()
+ }
+}
+
+impl<T, V> DoubleEndedIterator for ArenaMapIter<Idx<T>, V> {
+ #[inline]
+ fn next_back(&mut self) -> Option<Self::Item> {
+ while let Some(next_back) = self.iter.next_back() {
+ match Self::mapper(next_back) {
+ Some(r) => return Some(r),
+ None => continue,
+ }
+ }
+
+ None
+ }
+}
+
/// A view into a single entry in a map, which may either be vacant or occupied.
///
/// This `enum` is constructed from the [`entry`] method on [`ArenaMap`].