package monocle.function
import monocle.Optional
import scala.annotation.implicitNotFound
@implicitNotFound("Could not find an instance of Index[${S},${I},${A}], please check Monocle instance location policy to " +
"find out which import is necessary")
trait Index[S, I, A] extends Serializable {
def index(i: I): Optional[S, A]
}
object Index extends IndexFunctions
trait IndexFunctions {
def index[S, I, A](i: I)(implicit ev: Index[S, I, A]): Optional[S, A] = ev.index(i)
def atIndex[S, I, A](implicit ev: At[S, I, A]) = new Index[S, I, A] {
def index(i: I) = ev.at(i) composePrism monocle.std.option.some
}
}