Sha256: 44334ac3593b899c5571315572905aca78540dceebe0f040cfeab5d5ef066ec9
Contents?: true
Size: 1.29 KB
Versions: 13
Compression:
Stored size: 1.29 KB
Contents
use alloc::vec::Vec;
use std::iter::Fuse;
use std::ops::Index;
use crate::size_hint::{self, SizeHint};
#[derive(Debug, Clone)]
pub struct LazyBuffer<I: Iterator> {
it: Fuse<I>,
buffer: Vec<I::Item>,
}
impl<I> LazyBuffer<I>
where
I: Iterator,
{
pub fn new(it: I) -> Self {
Self {
it: it.fuse(),
buffer: Vec::new(),
}
}
pub fn len(&self) -> usize {
self.buffer.len()
}
pub fn size_hint(&self) -> SizeHint {
size_hint::add_scalar(self.it.size_hint(), self.len())
}
pub fn count(self) -> usize {
self.len() + self.it.count()
}
pub fn get_next(&mut self) -> bool {
if let Some(x) = self.it.next() {
self.buffer.push(x);
true
} else {
false
}
}
pub fn prefill(&mut self, len: usize) {
let buffer_len = self.buffer.len();
if len > buffer_len {
let delta = len - buffer_len;
self.buffer.extend(self.it.by_ref().take(delta));
}
}
}
impl<I, J> Index<J> for LazyBuffer<I>
where
I: Iterator,
I::Item: Sized,
Vec<I::Item>: Index<J>,
{
type Output = <Vec<I::Item> as Index<J>>::Output;
fn index(&self, index: J) -> &Self::Output {
self.buffer.index(index)
}
}
Version data entries
13 entries across 13 versions & 1 rubygems