CanBuildFrom example

canBuildFrom.scala

import scala.collection._
import scala.collection.generic._

implicit class TraversableLikeOps[+T, +Repr](val seq: SeqLike[T, Repr]) {
  def zipWithNext[That](implicit c: CanBuildFrom[Repr, (T, T), That]): That = {
    val builder = c(seq.repr)
    val is = seq.toIndexedSeq
    builder ++= is.zip(is.drop(1))
    builder.result
  }

  def zipWithNextImperitive[That](implicit c: CanBuildFrom[Repr, (T, T), That]): That = {
    val builder = c(seq.repr)
    val second = seq.toIterator.drop(1)
    seq.foreach{ elem =>
      if (second.hasNext) builder += (elem -> second.next())
    }
    builder.result
  }
}

println(Vector(1, 2, 3).zipWithNext)
println(Vector(1, 2, 3).zipWithNextImperitive)
println(List(1, 2, 3).zipWithNext)