Question

Edit

originally the question was “Collection to Tuple” as I assumed I needed a tuple in order to do variable multi-assignment. It turns out that one can do variable multi-assignment directly on collections. Retitled the question accordingly.

Original
Have a simple Seq[String] derived from a regex that I would like to convert to a Tuple.

What’s the most direct way to do so?

I currently have:

val(clazz, date) = captures match {
  case x: Seq[String] => (x(0), x(1))
}

Which is ok, but my routing layer has a bunch of regex matched routes that I’ll be doing val(a,b,c) multi-assignment on (the capture group is always known since the route is not processed if regex does not match). Would be nice to have a leaner solution than match { case.. => ..}

What’s the shortest 1-liner to convert collections to tuples in Scala?

Answer 1

This is not an answer to the question but might solve the problem in a different way.

You know you can match a xs: List[String] like so:

val a :: b :: c :: _ = xs 

This assigns the first three elements of the list to a,b,c? You can match other things like Seq in the declaration of a val just like inside a case statement. Be sure you take care of matching errors:

Catching MatchError at val initialisation with pattern matching in Scala?