Ronan Camargo RonanCamargo

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 cats.implicits._
	import cats.data.Ior

	case class Triangle(a: Double, b: Double, c: Double)
	case class Error(message: String)

	def validateSidesLength(input: Vector[Triangle]): Ior[Vector[Error], Vector[Triangle]] = {
	val (errors, successfuls) = input.foldLeft((Vector.empty[Error], Vector.empty[Triangle])){
	case ((errors, results), t@Triangle(a,b,c)) =>
	if(a > 0 && b > 0 && c > 0) (errors, results :+ t)

	tipoHuecoUtilizado* buscarHuecoPorPID(t_list* listaDeHuecosUtilizados,int pidProcesoBuscado){
	tipoHuecoUtilizado* aux;

	int pidBuscada(tipoHuecoUtilizado* huecoUtilizado){
	return pidProcesoBuscado == huecoUtilizado->pid;
	}

	aux = list_find(listaDeHuecosUtilizados,pidBuscada);

	return aux;

	t_persona crearPersona(char nom,int ed){
	t_persona *persona = malloc(sizeof(t_persona));
	persona->nombre=nom;
	persona->edad=ed;

	return persona;
	}

	void destruirPersona(t_persona* persona){
	free(persona->nombre);