When compiling this snippet, the scala compiler issues the following warning:
Eta-expansion of zero-argument method values is deprecated. Did you intend to write Main.this.porFiles5()? [warn] timerFunc(porFiles5)
It occurs when I pass a function to another one for a simple timing. The timer function takes a parameterless function returning unit, at this line: timerFunc(porFiles5). Is this warning necessary? What would be the idiomatic way to avoid it?
package example
import java.nio.file._
import scala.collection.JavaConverters._
import java.time._
import scala.collection.immutable._
object Main extends App {
val dir = FileSystems.getDefault.getPath("C:\\tmp\\testExtract")
def timerFunc (func:()=>Unit ) = {
val start = System.currentTimeMillis()
timeNow()
func()
val finish = System.currentTimeMillis()
timeNow()
println((finish - start) / 1000.0 + " secs.")
println("==================")
}
def porFiles5(): Unit = {
val porFiles5 = Files.walk(dir).count()
println(s"You have $porFiles5 por5 files.")
}
def timeNow(): Unit = {
println(LocalTime.now)
}
timeNow()
timerFunc(porFiles5)
timeNow()
}