// 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"(?::keyword_start:|\G(?!^)\S+)\K(?<!_end:)\s+").unwrap();
let string = "This is a teststring ... :keyword_start: this is the content with double spaces :keyword_end: more text ... :keyword_start: this is the second content with double spaces :keyword_end: ... more tex";
let substitution = " ";
// 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/