Cluster sequential elements given a predicate

cluster.scala

// given a list of elements and a predicate over those elements, 
// cluster the elements into a lists of lists of elements that fulfil the predicate, preserving the order of the original list.

def cluster[T](l:List[T], cond:List[T] => Boolean):List[List[T]] = {
  def splitCond[T](l:List[T], cond:List[T]=>Boolean):(List[T], List[T]) = {
    def splitCond0(l:List[T], cond:List[T]=>Boolean, cumm:List[T]):(List[T], List[T]) = l match {
      case Nil => (cumm, Nil)
      case h::t => if (cond(h::cumm)) splitCond0(t, cond, h::cumm) else (cumm,l)
    }
    splitCond0(l,cond,Nil)
  }
  
  l match {
    case Nil => Nil
    case list =>  val (grouped, rest) = splitCond(list, cond)
                  grouped :: cluster(rest, cond)
  }
}