match_string_re.js

const matchString = (s, patterns) => {
  	if (patterns.length === 0) {
      throw new Error('Not exhaustive string matching');
    } 
    const [matching, ...rest] = patterns;
    const [re, fn] = matching;
    if (re.test(s)) {
      const matches = re.exec(s);
      return matches ? fn(...matches) : fn();
    }
    return matchString(s, rest);
};