Question

What is the best way (concisest, clearest, idiomatic) to catch a MatchError, when assigning values with pattern matching?

Example:

val a :: b :: Nil = List(1,2,3) // throws scala.MatchError

The best way I found so far:

val a :: b :: Nil = try {
    val a1 :: b1 :: Nil = List(1,2,3)
    List(a1, b1)
  catch { case e:MatchError => // handle error here }

Is there an idiomatic way to do this?

Answer 1

Slightly improving on Kim’s solution:

val a :: b :: Nil = List(1, 2, 3) match {
  case x @ _ :: _ :: Nil => x
  case _ => //handle error
}

If you could provide more information on how you might handle the error, we could provide you a better solution.