mailbox 0.2.0

//            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
//                    Version 2, December 2004
//
// Copyleft (ↄ) meh. <meh@schizofreni.co> | http://meh.schizofreni.co
//
// Everyone is permitted to copy and distribute verbatim or modified
// copies of this license document, and changing it is allowed as long
// as the name is changed.
//
//            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
//   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
//
//  0. You just DO WHAT THE FUCK YOU WANT TO.

use std::io::{self, BufRead};

/// Iterator over ASCII lines.
///
/// The content of a line is not assumed to be in any specific encoding.
pub struct Lines<R: BufRead>(R, u64);

impl<R: BufRead> Lines<R> {
	/// Create a new `Iterator` from the given input.
	#[inline]
	pub fn new(input: R) -> Self {
		Lines(input, 0)
	}
}

impl<R: BufRead> Iterator for Lines<R> {
	type Item = io::Result<(u64, Vec<u8>)>;

	#[inline]
	fn next(&mut self) -> Option<Self::Item> {
		let mut buffer = Vec::new();
		let     offset = self.1;

		match self.0.read_until(b'\n', &mut buffer) {
			Ok(0) => {
				None
			}

			Ok(_) => {
				self.1 += buffer.len() as u64;

				if buffer.last() == Some(&b'\n') {
					buffer.pop();

					if buffer.last() == Some(&b'\r') {
						buffer.pop();
					}
				}

				Some(Ok((offset, buffer)))
			}

			Err(e) => {
				Some(Err(e))
			}
		}
	}
}