external interface is missing

[vitaly-t]

It doesn't seem right that a retry loop can only be interrupted (or interacted with) form inside the callback.

There are many scenarios when it needs to happen externally.

Function retry should return an object/interface for stopping, and even monitoring the current status:

var r = retry(cb);

if(/*something happenned*/ && r.attempts > 3) {
   r.stop();
   // or even with a reason:
   // r.stop(new Error('Had to stop externally'));
}

also, how about pausing the retries?

r.pause(); // pause unconditionally
// or
r.pause(100); // pause for 100 millisecond
// and resume:
r.resume(); // to resume the retries, if currently paused

plus access to the current status:

r.getStatus() // = running | finished | paused

[demmer]

At a high level I can see how this could be a nice addition to the project -- if you have an implementation with tests I'd be happy to review and include it but I'm not actively doing much if any development on this.