Simple ZLayer Example

HelloZioWithSimpleLayer.scala

package example

import zio.{IO, Layer, Task, ULayer, ZIO, ZIOAppDefault, ZLayer}
// Main
object ZioApp extends ZIOAppDefault:
  val app: Task[Unit] =
    ZIO.serviceWithZIO[GreetingService](_.sayHello)
      .provideLayer(GreetingModule.helloLayer)
  def run: Task[Unit] = app

class GreetingService():
  def sayHello: Task[Unit] = ZIO.logInfo("Hello, from GreetingService!")

object GreetingModule:
  val helloLayer: ULayer[GreetingService] = ZLayer.succeed(new GreetingService())