Multimethods

You could define the abstraction with multimethods:

1 (ns stadig.storage.methods

2   (:refer-clojure :exclude [get]))

3

4 (defmulti get :backend)

5 (defmulti put :backend)

6 (defmulti delete :backend)

7 (defmulti close :backend)

Implemented them for each backend:

1 (ns stadig.storage.s3

2   (:require

3    [aws.sdk.s3 :as s3]

4    [stadig.storage.methods :as methods]))

5

6 (defmethod methods/get :s3

7   [this bucket key]

8   (when-not bucket

9     (throw (ex-info "Expected bucket" {:type ::bucket-error})))

10   (s3/get-object this bucket key))

11

12 (defmethod methods/put :s3

13   [this bucket key value]

14   (when-not bucket

15     (throw (ex-info "Expected bucket" {:type ::bucket-error})))

16   (s3/put-object this bucket key value)...