Question

In javascript, we can do something like:

value = f1() || f2() || f3();

this will call f1, and assign it to value if the result is not null.
only if the result is null, it will call f2, and assign it to value if that is not null.
…

A way to achieve this in scala is given here: How to make this first-not-null-result function more elegant/concise?
create a getFirstNNWithOption function that calls each function until not null:

value = getFirstNNWithOption(List(f1 _, f2 _, f3 _))

However, this is not as nice as the javascript || operator, which is more flexible. eg:

value = f1() || f2(3) || f3(44, 'ddd') || value4;

is there a way to achieve this in scala?

Answer 1

I am using the recommended Option instead of null.
For example:

class OptionPimp[T](o: Option[T]) {
  def ||(opt: => Option[T]) = o orElse opt
  def ||(t: => T) = o getOrElse t
}
implicit def optionPimp[T](o: Option[T]) = new OptionPimp(o)

def f1(): Option[Int] = None
def f2(): Option[Int] = None
def f3(): Option[Int] = Some(3)

val value1 = f1() || f2() || f3() || 4 // yields 3
val value2 = f1() || f2()         || 4 // yields 4