Scala Question
Type Member w/ Implicit
Given:
// type-class
trait Eq[A]
class MyInt
object MyInt {
implicit val myIntEq = new Eq[MyInt] {}
}
sealed trait Something {
type A
implicit val x: Eq[A]
}
case object SomethingImpl extends Something {
override type A = MyInt
override implicit val x = MyInt.myIntEq
}
Then, I used the type member's
implicitscala> def f(s: Something): Eq[s.A] = {
| implicit val x: Eq[s.A] = s.x
| x
| }
f: (s: Something)Eq[s.A]
However, my instincts tell me that it's somewhat clumsy to have to bring the implicit into scope via
implicit val ...Perhaps I should define the
fSomethingWhat's the standard way to define this
f
Answer
If you want to bring a certain implicit into scope, you usually import it.
def f(s: Something) = {
import s.x
???
}
Source (Stackoverflow)