LimitedParSeq.scala

package core.common.datastructures

import scala.collection.generic.{GenericCompanion, CanBuildFrom}
import scala.collection.{SeqLike, mutable}
import scala.collection.mutable.ListBuffer

final class LimitedParSeq[T] private (internal: Seq[T], parLimit: Int) extends Seq[T] with SeqLike[T,LimitedParSeq[T]] {

	override def length: Int = internal.length

	override def apply(idx: Int): T = internal.apply(idx)

	override def iterator: Iterator[T] = internal.iterator

	override def foreach[U](f: T => U): Unit = internal.grouped(parLimit).foreach(_.par.foreach(f))

	override protected[this] def newBuilder: mutable.Builder[T, LimitedParSeq[T]] = LimitedParSeq.newBuilder[T]

	override def companion: GenericCompanion[LimitedParSeq] = LimitedParSeq
}

object LimitedParSeq extends GenericCompanion[LimitedParSeq]{
	
	def fromSeq[T](seq: Seq[T], parLimit: Int = 3) = new LimitedParSeq(seq, parLimit)

	override def apply[T](elems: T*) = fromSeq[T](elems)

	def newBuilder[T]: mutable.Builder[T, LimitedParSeq[T]] =
		new ListBuffer mapResult(fromSeq(_))

	implicit def canBuildFrom[T]: CanBuildFrom[Coll, T, LimitedParSeq[T]] =
		new CanBuildFrom[Coll, T, LimitedParSeq[T]] {
			def apply() = newBuilder[T]
			def apply(from: Coll) = newBuilder[T]
		}
}