Handle Scala Option idiomatically
You could always just look at the Scaladoc for Option:
The most idiomatic way to use an scala.Option instance is to treat it as a collection or monad and use map,flatMap, filter, or foreach:
val name: Option[String] = request getParameter "name"
val upper = name map { _.trim } filter { _.length != 0 } map { _.toUpperCase }
println(upper getOrElse "")
And a bit later:
A less-idiomatic way to use scala.Option values is via pattern matching:
val nameMaybe = request getParameter "name"
nameMaybe match {
case Some(name) =>
println(name.trim.toUppercase)
case None =>
println("No name value")
}
Use fold
for this kind of map-or-else-default thing:
val x = option.fold(0.5){ value => Math.cos(value) + Math.sin(value) }