// include the latest version of the regex crate in your Cargo.toml
extern crate regex;
use regex::Regex;
fn main() {
let regex = Regex::new(r"(.)\n(?!\n)").unwrap();
let string = "I have a text file where lines are trimmed by newline characters.
I want to strip out those single newlines and replace with simple spaces.
But I do not want the double newlines affected.
This line should start after 2 line breaks.
Everything I try inevitably ends up affecting those double new lines too.
This line should also start after 2 line breaks.
This can be solved using lookaheads.";
let substitution = "\\1 ";
// result will be a String with the substituted value
let result = regex.replace_all(string, substitution);
println!("{}", result);
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Rust, please visit: https://docs.rs/regex/latest/regex/