eithert.scala

import cats.effect.kernel.Resource
import cats.effect.IO
import cats.data.EitherT

trait Client {
  def get(uri: String): IO[String]
}
val client: Resource[IO, Client] = Resource.pure(new {
  def get(uri: String): IO[String] = IO.pure("result")
})

def parseUri(str: String): Either[String, String] = Right("http://example.com/")

def call(): EitherT[IO, String, String] = EitherT(client.use { c =>
  (for
    uri <- EitherT.fromEither[IO](parseUri("http://foo.example.com/"))
    res <- EitherT.right[String](c.get(uri))
  yield res).value
})