use super::abstract_mut::FastAbstractMut;
#[allow(missing_docs)]
pub struct FastChunk<Storage> {
pub(super) storage: Storage,
pub(super) current: usize,
pub(super) end: usize,
pub(super) step: usize,
}
impl<Storage: FastAbstractMut> Iterator for FastChunk<Storage> {
type Item = Storage::Slice;
#[inline]
fn next(&mut self) -> Option<Self::Item> {
if self.current + self.step < self.end {
self.current += self.step;
Some(unsafe {
FastAbstractMut::get_data_slice(
&self.storage,
self.current - self.step..self.current,
)
})
} else if self.current < self.end {
let result = Some(unsafe {
FastAbstractMut::get_data_slice(&self.storage, self.current..self.end)
});
self.current = self.end;
result
} else {
None
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let exact = (self.end - self.current + self.step - 1) / self.step;
(exact, Some(exact))
}
#[inline]
fn fold<B, F>(mut self, mut init: B, mut f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
while self.current + self.step < self.end {
self.current += self.step;
init = f(init, unsafe {
FastAbstractMut::get_data_slice(
&self.storage,
self.current - self.step..self.current,
)
});
}
if self.current < self.end {
init = f(init, unsafe {
FastAbstractMut::get_data_slice(&self.storage, self.current..self.end)
});
self.current = self.end;
}
init
}
}
impl<Storage: FastAbstractMut> ExactSizeIterator for FastChunk<Storage> {
#[inline]
fn len(&self) -> usize {
(self.end - self.current + self.step - 1) / self.step
}
}
impl<Storage: FastAbstractMut> DoubleEndedIterator for FastChunk<Storage> {
#[inline]
fn next_back(&mut self) -> Option<Self::Item> {
if self.current + self.step < self.end {
self.end -= self.step;
Some(unsafe {
FastAbstractMut::get_data_slice(&self.storage, self.end..self.end + self.step)
})
} else {
None
}
}
#[inline]
fn rfold<B, F>(mut self, mut init: B, mut f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
while self.current + self.step < self.end {
self.end -= self.step;
init = f(init, unsafe {
FastAbstractMut::get_data_slice(&self.storage, self.end..self.end + self.step)
});
}
init
}
}