collectFirstM using cats

collectFirst.scala

import cats.implicits._

object CollectFirstM {

  implicit class CollectFirstMSyntax[F[_], A](val xs: Seq[A]) extends AnyVal {

    def collectFirstM[B, M[_]](f: A => M[Option[B]])(implicit M: Monad[M]): M[Option[B]] =
      M.tailRecM(xs) {
        case x +: rest => f(x).map {
          case some@Some(_) => Right(some)
          case None => Left(rest)
        }
        case _ => Either.right[Seq[A], Option[B]](None).pure[M]
      }

  }

}