Fx

Fx

If you use Monix and write tagless final code, and look for a generic way to construct F[A], Fx can help you.

import effectie.core._

trait Something[F[_]] {
  def get[A](a: => A): F[A]
}

object Something {
  def apply[F[_]: Something]: Something[F] =
    implicitly[Something[F]]

  implicit def something[F[_]: Fx]: Something[F] =
    new SomethingF[F]

  final class SomethingF[F[_]: Fx]
    extends Something[F] {

    def get[A](a: => A): F[A] =
      Fx[F].effectOf(a)
  }
}

import monix.eval._
import monix.execution.Scheduler.Implicits.global

import effectie.instances.monix3.fx._

val get1 = Something[Task].get(1)
// get1: Task[Int] = Eval(thunk = <function0>)

get1.runSyncUnsafe()
// res1: Int = 1

If you feel it's too cumbersome to repeat Fx[F].effectOf(), consider using effectie.syntax.

Syntax

If you're sick of repeating Fx[F].effectOf() and looking for more convenient ways?, use Effectful instead.

import effectie.syntax.all._
import effectie.core._

trait Something[F[_]] {
  def get[A](a: => A): F[A]
}

object Something {
  def apply[F[_]: Something]: Something[F] =
    implicitly[Something[F]]

  implicit def something[F[_]: Fx]: Something[F] =
    new SomethingF[F]

  final class SomethingF[F[_]: Fx]
    extends Something[F] {

    def get[A](a: => A): F[A] =
      effectOf(a)
      // No more Fx[F].effectOf(a)
  }
}

import monix.eval._
import monix.execution.Scheduler.Implicits.global

import effectie.instances.monix3.fx._

val get1 = Something[Task].get(1)
// get1: Task[Int] = Eval(thunk = <function0>)

get1.runSyncUnsafe()
// res3: Int = 1