dependency.CovariantSet.scala Maven / Gradle / Ivy
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package dependency
import scala.collection.IterableOps
import scala.collection.IterableFactoryDefaults
import scala.collection.IterableFactory
import scala.collection.mutable.Builder
class CovariantSet[+A] private (private val elements: List[A])
extends Iterable[A]
with IterableOps[A, CovariantSet, CovariantSet[A]]
with IterableFactoryDefaults[A, CovariantSet] {
protected[this] override def className: String = "CovariantSet"
def +=[B >: A](elem: B): CovariantSet[B] =
if (elements.contains(elem))
this
else
new CovariantSet[B](elem :: elements)
def iterator: Iterator[A] =
elements.iterator
override def iterableFactory: IterableFactory[CovariantSet] =
CovariantSet
override def equals(obj: Any): Boolean =
if (obj == null) false
else if (this eq obj.asInstanceOf[AnyRef]) true
else if (obj.isInstanceOf[CovariantSet[_]]) {
val other = obj.asInstanceOf[CovariantSet[_]]
elements.toSet == other.elements.toSet
}
else super.equals(obj)
}
object CovariantSet extends IterableFactory[CovariantSet] {
def from[A](source: IterableOnce[A]): CovariantSet[A] =
new CovariantSet[A](source.iterator.toList.distinct)
def empty[A]: CovariantSet[A] =
new CovariantSet[A](Nil)
def newBuilder[A]: Builder[A, CovariantSet[A]] =
new Builder[A, CovariantSet[A]] {
val underlying = collection.mutable.Set.newBuilder[A]
def addOne(elem: A): this.type = {
underlying.addOne(elem)
this
}
def clear(): Unit = underlying.clear()
def result(): CovariantSet[A] = new CovariantSet[A](underlying.result().toList)
}
}