rust in a string, replace multiple spaces with single space

To replace multiple spaces with a single space in a Rust string, you can use regular expressions. Here's an example code snippet that demonstrates how to achieve this:

use regex::Regex;

fn main() {
    let input = "Hello    World   Rust";
    let re = Regex::new(r"\s+").unwrap();
    let result = re.replace_all(input, " ");
    println!("{}", result);

In this code, we first import the Regex module from the regex crate. We then define the input string input which contains multiple spaces. Next, we create a regular expression re using the Regex::new function. The regular expression \s+ matches one or more whitespace characters. Finally, we use the replace_all method to replace all matches of the regular expression with a single space.

When you run this code, it will output:

Hello World Rust

This demonstrates that the multiple spaces in the input string have been replaced with a single space.