[sciolistse]

In generator code you'd use try/catch to handle failure instead.

    try {
      var user = yield Users.get(1234);
      return user.name;
    } catch(ex) {
      // do whatever
    }

rather than..

    return Users.get(1234).then(
      function (u) { return u.name; },
      function (ex) { /* do whatever */ }
    );

[spion]

Those are not entirely equivalent. For example, if you make a typo when writing "user" or "u", the first one will catch that typo (cannot get property name of undefined) while the second one will not.

  Users.get(1234)
    .then(u => u.name)
    .catch(ex => 1/* do whatever */);