bytelines

This library provides an easy way to read in input lines as byte slices for high efficiency. It's basically lines from the standard library, but it reads each line as a byte slice (&[u8]). This performs significantly faster than lines() in the case you don't particularly care about unicode, and basically as fast as writing the loops out by hand. Although the code itself is somewhat trivial, I've had to roll this in at least 4 tools I've written recently and so I figured it was time to have a convenience crate for it.

Installation

This tool will be available via Crates.io, so you can add it as a dependency in your Cargo.toml:

[dependencies]
bytelines = "2.0"

Usage

It's quite simple; in the place you would typically call lines on a BufRead implementor, you can now call byte_lines to retrieve a structure used to walk over lines as &[u8] (and thus avoid allocations).

let file = File::open("./my-input.txt").expect("able to open file");
let mut lines = BufReader::new(file).byte_lines();

while let Some(line) in lines.next() {
    // do something with the line
}

In the 1.x lineage of bytelines, the Iterator trait was implemented for ByteLines and thus allowed the typical for $x in $y syntax. As this required unsafe code, this has been removed in favour of the syntax above which allows a completely safe API without impacting the internal performance.