'use strict';

function uuid() {
  try {
    return ([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g,
      c => (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4)
            .toString(16));
  } catch (e) {
    // fallback, as the Tor Browser seems to fail above
    uuid = () => 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
      let r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
      return v.toString(16);
    });
  }
}