// 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"(?m)([^\v]{0,80})(?:\s|$)").unwrap();
let string = "There are usually about 200 words in a paragraph, but this can vary widely. Most paragraphs focus on a single idea that's expressed with an introductory sentence, then followed by two or more supporting sentences about the idea. A short paragraph may not reach even 50 words while long paragraphs can be over 400 words long, but generally speaking they tend to be approximately 200 words in length.";
let substitution = "$1\\n";
// 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/