scala> val m = Map(1 -> 2) m: scala.collection.immutable.Map[Int,Int] = Map(1 -> 2) scala> m.map{case (a, b) => (a+ 1, a+2, a+3)} res42: scala.colle
Combining Ben and oxbow_lakes' answers, you can get a little shorter still:
type I3 = (Int, Int, Int) m.map {case (a, b) ⇒ (a+1, a+2, a+3)}(breakOut): List[I3]