retry async

retryAsync.fsx

    open System

    type RetryPolicy = Policy of (int -> exn -> TimeSpan option)

    /// retries given action based on given policy
    let retryAsync (Policy p) (f : Async<'T>) =
        let rec aux retries =
            async {
                let! result = Async.Catch f

                match result with
                | Choice1Of2 t -> return t
                | Choice2Of2 e ->
                    match p (retries + 1) e with
                    | None -> return raise e
                    | Some interval ->
                        do! Async.Sleep (int interval.TotalMilliseconds)
                        return! aux (retries + 1)
            }

        aux 0