Scala: List of pairs to pair of lists

Question

I have a list of pairs:

val pairs = List("a" -> 1, "b" -> 2, "c" -> 3)

I'd like to convert it to a pair of lists:

List("a", "b", "c") -> List(1, 2, 3)

Basically, I want the opposite of zip()

Any elegant way of doing so?

@LuigiPlinge: I don't downvote people, I downvote questions and answers. The people who post them should stop taking it personally. Sadly there is still no way to downvote comments. ;) Besides, I am only one of 3 people who downvoted. — Kim Stebel, Oct 30 '12 at 10:43

score 18 · Accepted Answer · answered Oct 29 '12 at 16:49

18

The opposite of zip? What might that be? unzip maybe?

scala> List("a" -> 1, "b" -> 2, "c" -> 3).unzip
res0: (List[java.lang.String], List[Int]) = (List(a, b, c),List(1, 2, 3))

answered Oct 29 '12 at 16:49

Kim Stebel

1

Hmmm. Can't see how I missed that :) – Electric Monk Oct 29 '12 at 17:06
1

You probably missed it because the documentation of zip does not contain a link to unzip as an inverse. I'll see what I can do about this. – iainmcgin Oct 30 '12 at 13:04

1 Answers1