Suppose I have two Options and, if both are Some, execute one code path, and if note, execute another. I'd like to do something like
for (x <- xMaybe; y <- yMaybe) {
// do something
}
else {
// either x or y were None, handle this
}
Outside of if statements or pattern matching (which might not scale if I had more than two options), is there a better way of handling this?
Very close to your syntax proposal by using yield to wrap the for output in an Option:
val result = {
for (x <- xMaybe; y <- yMaybe) yield {
// do something
}
} getOrElse {
// either x or y were None, handle this
}
The getOrElse block is executed only if one or both options are None.
You could pattern match both Options at the same time:
(xMaybe, yMaybe) match {
case (Some(x), Some(y)) => "x and y are there"
case _ => "x and/or y were None"
}
For scaling to many options, try something along these lines:
def runIfAllSome[A](func:(A)=>Unit, opts:Option[A]*) = {
if(opts.find((o)=>o==None) == None) for(opt<-opts) func(opt.get)
}
With this, you can do:
scala> def fun(i:Int) = println(i)
fun: (i: Int)Unit
scala> runIfAllSome(fun, Some(1), Some(2))
1
2
scala> runIfAllSome(fun, None, Some(1))
scala>