Early Exit?

[rbtcollins]

Perhaps I'm missing it but it seems like there is no way to signal that the function cannot complete and no further retries should be attempted?

e.g. the particular scenario we have is trying a file rename where
Ok(()) -> Done
Err(AccessDenied) -> Retry
Err(_) -> propogate this error

[rbtcollins]

If I'm right, happy to put a patch forward (subject to #18)

[rbtcollins]

Some some thoughts - I could presumably have a duration iterator that is coupled with the operation closure somehow, but ownership issues aside this seems a little ugly?

We could change the signature of O from -> Result to some other Enum, e.g. a three-valued one RetryResult<R, E> and supply a From for Result for that so that most users can just ignore it?

Ok(value) -> Ok (value)
Err(error) -> existing code
Fatal(error) -> Err(Error::Operation { error :: error ....}