Min/max with Option[T] for possibly empty Seq?

Question

I\'m doing a bit of Scala gymnastics where I have Seq[T] in which I try to find the \"smallest\" element. This is what I do right now:

val leastOrNo         


        

Answer 1

You could always do something like:

case class Foo(num: Int)

val foos: Seq[Foo] = Seq(Foo(1), Foo(2), Foo(3))
val noFoos: Seq[Foo] = Seq.empty

def minByOpt(foos: Seq[Foo]): Option[Foo] =
  foos.foldLeft(None: Option[Foo]) { (acc, elem) => 
    Option((elem +: acc.toSeq).minBy(_.num)) 
  }

Then use like:

scala> minByOpt(foos)
res0: Option[Foo] = Some(Foo(1))

scala> minByOpt(noFoos)
res1: Option[Foo] = None