protocol-record test

gistfile1.txt

file: backside_api.clj
(ns stm4clj.backside_api)

(defprotocol IBackside
  (put-proxy [proxy])   ;; wavering on whether "this" is needed
  (get-proxy [locator])
  (delete-proxy [locator])
  (find-proxy [query])
  (list-proxies [offset count])
  )

file DhPgBackside.clj
(ns stm4clj.DhPgBackside
  (:require ;; [stm4clj.types :as t]
            ;; [datahike.api :as d]
            ;; [stm4clj.postgres :as pg]
            [stm4clj.backside_api :as api]))
;;;;;;;;;;;
;; This is an IBackside implementation which
;; drives Datahike which is persisting with Postgres
;; @see https://www.juxt.pro/blog/abstract-clojure#_protocols
;;;;;;;;;;;

;;(defn boot-db
;;  "boot the database
;;  Intended to eventually validate there is a database and
;;  otherwise configure one if not"
;;  []
;;  (pg/create-db)
;;  (println "Booted"))

(defrecord DhPgBackside []
  api/IBackside
  (put-proxy [this proxy]  ;; wavering of whether "this" is needed
    (println "Put" proxy)  ;; for testing
    nil)
  (get-proxy [locator]
    nil)
  (delete-proxy [locator]
    nil)
  (find-proxy [query]
    nil)
  (list-proxies [offset count]
    nil)
)

file: core.clj  This is where it's problematic how to require/import the implementation and use it
(ns stm4clj.core
  (:require
    [stm4clj.DhPgBackside])
  (:gen-class))

(defn foo
  []
  (DhPgBackside/put-proxy  "foo")
  (println "Hello, World!"))

(require '[stm4clj.DhPgBackside :as bc]
      '[stm4clj.backside_api :as api]
)

(let [pg (bc/->DhPgBackside)]
  (api/put-proxy pg "foo"))

That made it work just fine. Many thanks!

@KnowledgeGarden happy to help! Protocols and records are somewhat confusing as there's a bit of magic going on under the hood (particularly around how protocols are turned into interfaces and automatic creation of factory functions for records), but once you grok it, it all works quite nicely together - just don't over do it - idiomatic Clojure code mostly operates on data rather than concrete types/classes etc