/**
 * Creates a RegExp from the given string, converting asterisks to .* expressions,
 * and escaping all other characters.
 */
function wildcardToRegExp (s) {
  return new RegExp('^' + s.split(/\*+/).map(regExpEscape).join('.*') + '$');
}

/**
 * RegExp-escapes all characters in the given string.
 */
function regExpEscape (s) {
  return s.replace(/[|\\{}()[\]^$+*?.]/g, '\\$&');
}