For example
object TimeHelpers {
def seconds(in: Long): Long = in * 1000L
}
import TimeHelpers._
class Base {
seconds(1000L)
}
// separate file
class Base2 extends Base {
// does not compile
//seconds(1000L)
}
Do I have to manually import for Base2 or is there a way to automatically do t开发者_如何学Pythonhis?
There's no such mechanism, sorry.
One trick, though, is to use trait inheritance rather than imports. This can be a useful way of grouping what would otherwise be multiple imports. For example,
trait Helpers1 {
def seconds(in: Long): Long = in * 1000L
}
trait Helpers2 {
def millis(in: Long): Long = in * 1000000L
}
class Base {
protected object helpers extends Helpers1 with Helpers2
}
// separate file
class Base2 extends Base {
// References to helper functions can be qualified:
helpers.seconds(1000L)
helpers.millis(1000L)
// Or, can import multiple helper traits with one line:
import helpers._
seconds(1000L)
millis(1000L)
}
Another possibility is to have Base
inherit Helpers1 with Helpers2
, but then you'd probably want the methods to be protected
.
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