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use crate::io::io::read_line::read_line_internal;
use crate::io::AsyncBufRead;
use futures_core::{ready, Stream};
use pin_project::{pin_project, project};
use std::io;
use std::mem;
use std::pin::Pin;
use std::task::{Context, Poll};
/// Stream for the [`lines`](crate::io::AsyncBufReadExt::lines) method.
#[pin_project]
#[derive(Debug)]
#[must_use = "streams do nothing unless polled"]
pub struct Lines<R> {
#[pin]
reader: R,
buf: String,
bytes: Vec<u8>,
read: usize,
}
pub(crate) fn lines<R>(reader: R) -> Lines<R>
where
R: AsyncBufRead,
{
Lines {
reader,
buf: String::new(),
bytes: Vec::new(),
read: 0,
}
}
impl<R: AsyncBufRead> Stream for Lines<R> {
type Item = io::Result<String>;
#[project]
fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
#[project]
let Lines {
reader,
buf,
bytes,
read,
} = self.project();
let n = ready!(read_line_internal(reader, cx, buf, bytes, read))?;
if n == 0 && buf.is_empty() {
return Poll::Ready(None);
}
if buf.ends_with('\n') {
buf.pop();
if buf.ends_with('\r') {
buf.pop();
}
}
Poll::Ready(Some(Ok(mem::replace(buf, String::new()))))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn assert_unpin() {
crate::is_unpin::<Lines<()>>();
}
}
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