Protocol + Client Namespace + Multimethod

You could use a protocol to define the abstraction, except connect, which is a multimethod:

1 (ns stadig.storage.protocol

2   (:refer-clojure :exclude [get]))

3

4 (defprotocol IStorage

5   (get [this bucket key])

6   (put [this bucket key value])

7   (delete [this bucket key])

8   (close [this]))

9

10 (defmulti connect :backend)

Implement the protocol and multimethod for each backend:

1 (ns stadig.storage.s3

2   (:require

3    [aws.sdk.s3 :as s3]

4    [stadig.storage.protocol :as proto]))

5

6 (defrecord S3Storage

7     [access-key secret-key]

8   proto/IStorage

9   (get [this bucket key]

10     (s3/get-object this bucket key))

11   (put [this bucket key value]

12     (s3/put-object this bucket key value...