use crate::fragment::fragment_struct::Fragment;
use std::iter::FusedIterator;
#[derive(Debug)]
pub struct Iter<'a, T> {
pub(crate) fragments: &'a [Fragment<T>],
pub(crate) f: usize,
pub(crate) i: usize,
}
impl<'a, T> Iter<'a, T> {
pub(crate) fn new(fragments: &'a [Fragment<T>]) -> Self {
let f = 0;
let i = 0;
Self { fragments, f, i }
}
}
impl<'a, T> Clone for Iter<'a, T> {
fn clone(&self) -> Self {
Self {
fragments: self.fragments,
f: self.f,
i: self.i,
}
}
}
impl<'a, T> Iterator for Iter<'a, T> {
type Item = &'a T;
#[inline(always)]
fn next(&mut self) -> Option<Self::Item> {
if self.i == self.fragments[self.f].len() {
self.f += 1;
self.i = 1;
self.fragments.get(self.f).and_then(|f| f.get(0))
} else {
self.i += 1;
self.fragments[self.f].get(self.i - 1)
}
}
}
impl<T> ExactSizeIterator for Iter<'_, T> {
fn len(&self) -> usize {
self.fragments
.iter()
.skip(self.f + 1)
.map(|x| x.len())
.sum::<usize>()
+ if self.f == self.fragments.len() || self.i == self.fragments[self.f].len() {
0
} else {
self.fragments[self.f].len() - self.i
}
}
}
impl<T> FusedIterator for Iter<'_, T> {}