use crate::{Buffer, Reader, VectorReader};
use std::iter::{DoubleEndedIterator, ExactSizeIterator, FusedIterator, Iterator};
pub struct ReaderIterator<B> {
pub(super) reader: VectorReader<B>,
pub(super) front: usize,
end: usize,
}
impl<B: Buffer> ReaderIterator<B> {
pub(super) fn new(reader: VectorReader<B>) -> Self {
let end = reader.len();
ReaderIterator { reader, front: 0, end }
}
}
impl<B: Buffer> Iterator for ReaderIterator<B> {
type Item = Reader<B>;
fn next(&mut self) -> Option<Self::Item> {
if self.front < self.end {
let r = self.reader.idx(self.front);
self.front += 1;
Some(r)
} else {
None
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
let remaining = self.end - self.front;
(remaining, Some(remaining))
}
}
impl<B: Buffer> DoubleEndedIterator for ReaderIterator<B> {
fn next_back(&mut self) -> Option<Self::Item> {
if self.front < self.end {
self.end -= 1;
Some(self.reader.idx(self.end))
} else {
None
}
}
}
impl<B: Buffer> ExactSizeIterator for ReaderIterator<B> {}
impl<B: Buffer> FusedIterator for ReaderIterator<B> {}