// 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)^(?=.{3,20}$)[a-z0-9]+([_][a-z0-9]+)*$").unwrap();
let string = "a_123
1_1
amit12343
12ami
a_457_h
a__a
a_______0_
_0_sd
0_0
12
a1
123456789012345678901";
// result will be an iterator over tuples containing the start and end indices for each match in the string
let result = regex.captures_iter(string);
for mat in result {
println!("{:?}", mat);
}
}
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/