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