scala.tools.nsc.transform.async.StateSet.scala Maven / Gradle / Ivy

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/*
 * Scala (https://www.scala-lang.org)
 *
 * Copyright EPFL and Lightbend, Inc.
 *
 * Licensed under Apache License 2.0
 * (http://www.apache.org/licenses/LICENSE-2.0).
 *
 * See the NOTICE file distributed with this work for
 * additional information regarding copyright ownership.
 */

package scala.tools.nsc.transform.async

import java.util
import java.util.function.{Consumer, IntConsumer}

import scala.jdk.CollectionConverters._

// Set for StateIds, which are either small positive integers or -symbolID.
final class StateSet {
  private val bitSet = new java.util.BitSet()
  private var _caseSet: util.HashSet[Integer] = null
  private def caseSet: util.HashSet[Integer] = {
    if (_caseSet == null) _caseSet = new util.HashSet[Integer]()
    _caseSet
  }

  private def useBitSet(i: Int) = i > 0 && i < 1024
  def +=(stateId: Int): Unit = if (useBitSet(stateId)) bitSet.set(stateId) else caseSet.add(stateId)
  def -=(stateId: Int): Unit = if (useBitSet(stateId)) bitSet.clear(stateId) else caseSet.remove(stateId)
  def iterator: Iterator[Integer] = {
    bitSet.stream().iterator().asScala ++ (if (_caseSet == null) Nil else _caseSet.asScala.iterator)
  }
  def toArray: Array[Int] = {
    val result = new Array[Int](bitSet.cardinality() + (if (_caseSet == null) 0 else caseSet.size()))
    var i = 0
    foreach(value => {result(i) = value; i += 1 })
    result
  }
  def foreach(f: IntConsumer): Unit = {
    bitSet.stream().forEach(f)
    if (_caseSet != null) {
      caseSet.stream().forEach(new Consumer[Integer] {
        override def accept(value: Integer): Unit = f.accept(value)
      })
    }
  }
  override def toString: String = toArray.sorted.toSeq.mkString("[", ",", "]")
}