Exponential backoff with max delay

[foxware00]

The RetryConstraint enum exponential case seems it will infinitely grow exponentially.
My suggestion is to add an additional field for maxDelay such that.
.exponential(initial: TimeInterval, maxDelay: TimeInterval) to prevent it growing uncontrollably. Does this sound like something appropriate for this lib? Happy to construct a PR of you need some help.

let delay = info.currentRepetition == 1 ? initial : initial * pow(2, Double(info.currentRepetition - 1))
return min(maxDelay, delay)

[lucas34]

Sounds good to me ! Can you send a PR ?

[foxware00]

Of course. One issue I foresee is exponential enum won't allow default parameters and adding maxDelay would be a breaking change to the API.

I can think of a few options

1. Add a new `expontentialWithMax(initial: TimeInterval, maxDelay: TimeInterval)
   verbose but non-breaking
2. Change RetryConstraint to a struct to allow multiple factory methods and a private constructor to allow for the same method names, a non-breaking change but we wouldn't be able to use the switch statement inside retryJob
3. Have factory methods inside the enum named as they are today and rename the enum cases to something else. This gives us two ways to create each case which might be confusing.
4. Add maxDelay and cause a breaking change (worst option)

Any preference, thoughts or different solutions to the above?

[lucas34]

In my opinion it's better to go with the most straight forward solution. The solution 1 looks good to me