// source: https://swizec.com/blog/finally-a-practical-use-case-for-javascript-generators/swizec/9036
const UserRegex = new RegExp(/@(\w+)/, "g");

function* regexGenerator(string, regex) {
    let match = null;

    do {
        match = regex.exec(string);
        if (match) {
            yield match;
        }
    } while (match);
}

const string = "this is a test with @swizec and @kyleshevlin, maybe @lukeed05";

const getUsernames = regexGenerator(string, UserRegex);

for (const username of getUsernames) {
  console.log(username)
  // ["@swizec", "swizec"]
  // ["@kyleshevlin", "kyleshevlin"]
  // ["@lukeed05", "lukeed05"]
}

console.log(Array.isArray(string.matchAll(UserRegex)))