Eunmin Kim eunmin

Dependency Injection in Functional Programming

There exist several DI frameworks / libraries in the Scala ecosystem. But the more functional code you write the more you'll realize there's no need to use any of them.

A few of the most claimed benefits are the following:

Dependency Injection.
Life cycle management.
Dependency graph rewriting.

	import Foundation

	let url = URL(string: "http://webtoon.daum.net/data/pc/webtoon/list_daily_ranking/serialized?pageSize=5&timeStamp=1531916119497")

	struct Ranking : Decodable {
	let title : String
	}

	struct Webtoon : Decodable {
	let data: [Ranking]

	import Foundation

	let url = URL(string: "http://webtoon.daum.net/data/pc/webtoon/list_daily_ranking/serialized?pageSize=5&timeStamp=1531916119497")

	let data = try! Data(contentsOf: url!)

	let webtoon = try JSONSerialization.jsonObject(with: data, options: []) as! NSDictionary

	for item in webtoon["data"] as! NSArray {
	let ranking = item as! NSDictionary

	(ns example.hello)

	(def a 1)

	(defn add [x y]
	(+ x y))

	type JsonValue
	= JsonString String
	\| JsonNumber Int
	\| JsonNull
	\| JsonArray List JsonValue
	\| JsonObject Dict String JsonValue

	user : Dict String JsonValue
	user =
	Dict.fromList [ ( "name"

	(defun cider-load-buffer-all-connections ()
	(let ((curr (cider-current-connection)))
	(dolist (conn cider-connections)
	(cider-make-connection-default conn)
	(cider-load-buffer))
	(cider-make-connection-default curr)))