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Fx

Fx

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

import effectie.cats._

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 cats.effect._

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

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

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

Effectful

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

import effectie.cats.Effectful._
import effectie.cats._

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 cats.effect._

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

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