Merge case class in a sequence

Question

I am trying to merge case class in a sequences. ie I have the following case class:

case class Output(a: String , b: String, c: String, d: Int)

val outputSeq = Seq(
  Output("serviceA","targetA","8000",0),
  Output("serviceA","targetA","8080",1),
  Output("serviceA","targetA","8000",0)
)

I would like to achieve the following output:

  Map(serviceA -> List(Output(serviceA, targetA, 8080, 0), Output(serviceA, targetA, 8080, 1))

following gives me the map but I am stuck how to get rid of duplicates. I know I need to further filter using map but I am a noob in scala FP.

outputSeq.groupBy(_.a)

Answer 1

Since mapValues() has been deprecated (as of Scala 2.13.0) it's recommended that we use the long form.

outputSeq.groupBy(_.a)
         .map{case (k,vs) => k -> vs.distinct}

Answer 2

Silly me. I could do.

outputSeq.distinct.groupBy(_.a)

I am loving scala. :)