Scala ifNotPresent concise form

Question

I have the following collection:

private val commandChain: mutable.Buffer[mutable.Buffer[Long]] = ArrayBuffer()

I need to do the following:

def :->(command: Long) = {
  commandChain.headOption match {
    case Some(node) => node += command
    case None => commandChain += ArrayBuffer(command)
  }
}

Is there more concise form of this than pattern matching?

score 1 · Accepted Answer · answered Aug 01 '17 at 07:42

1

You could just go with a simple if...else statement. No pattern matching and no Option unwrapping.

def :->(command: Long): Unit = 
  if (commandChain.isEmpty) commandChain += ArrayBuffer(command)
  else                      commandChain.head += command

BTW, this is way more mutable data structures and side effects than is seen in most idiomatic (i.e. "good") Scala.

answered Aug 01 '17 at 07:42

jwvh

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You mean this is faster? – St.Antario Aug 01 '17 at 07:43
Perhaps, but I think you'd be hard pressed to find a measurable difference in performance. This is just slightly more concise and offers a bit more readability and clarity-of-purpose, IMHO. – jwvh Aug 01 '17 at 07:50

Scala ifNotPresent concise form

1 Answers1