// 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"(?<=[0-9a-zA-Z])\h*([+\-\=])\h*(-?[0-9a-zA-Z])").unwrap();
let string = "+5 + 3
+5+3=3
-d+7
-1-a
+3
+4
-1
3+
4-";
let substitution = " $1 $2";
// 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/