squiid/rust
1
0
Fork 0
Code Issues Pull requests Projects Activity

core: Implement fold / rfold for Rev

Browse source 
With both in place, we can cross them over in rev, and we give rfold
behaviour to .rev().fold() and so on.
This commit is contained in:
Ulrik Sverdrup 2017-09-18 21:24:33 +02:00
parent 91318c8cab
commit 31cf26a953
1 changed files with 12 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

12
src/libcore/iter/mod.rs
View file

@ -359,6 +359,12 @@ impl<I> Iterator for Rev<I> where I: DoubleEndedIterator {
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
fn fold<Acc, F>(self, init: Acc, f: F) -> Acc
where F: FnMut(Acc, Self::Item) -> Acc,
{
self.iter.rfold(init, f)
}
#[inline]
fn find<P>(&mut self, predicate: P) -> Option<Self::Item>
where P: FnMut(&Self::Item) -> bool
@ -379,6 +385,12 @@ impl<I> DoubleEndedIterator for Rev<I> where I: DoubleEndedIterator {
#[inline]
fn next_back(&mut self) -> Option<<I as Iterator>::Item> { self.iter.next() }
fn rfold<Acc, F>(self, init: Acc, f: F) -> Acc
where F: FnMut(Acc, Self::Item) -> Acc,
{
self.iter.fold(init, f)
}
fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item>
where P: FnMut(&Self::Item) -> bool
{