// 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"(?=(https?://\S+))(?|\1 \[([^]]+)\]|(\1))").unwrap();
let string = "http://stackoverflow.com/ [click here] bla bla bla
http://www.google.com/ bla bla bla";
let substitution = "<a href=\"$1\">$2</a>";
// 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/