Scala example source code file (ArrayBuilder.scala)

This example Scala source code file (ArrayBuilder.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

any, anyref, array, arraybuilder, boolean, classtag, double, int, reflection, runtime, serializable, traversableonce

The ArrayBuilder.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

package scala
package collection
package mutable

import scala.reflect.ClassTag
import scala.runtime.ScalaRunTime

/** A builder class for arrays.
 *
 *  @since 2.8
 *
 *  @tparam T    the type of the elements for the builder.
 */
abstract class ArrayBuilder[T] extends Builder[T, Array[T]] with Serializable

/** A companion object for array builders.
 *
 *  @since 2.8
 */
object ArrayBuilder {

  /** Creates a new arraybuilder of type `T`.
   *
   *  @tparam T     type of the elements for the array builder, with a `ClassTag` context bound.
   *  @return       a new empty array builder.
   */
  def make[T: ClassTag](): ArrayBuilder[T] = {
    val tag = implicitly[ClassTag[T]]
    tag.runtimeClass match {
      case java.lang.Byte.TYPE      => new ArrayBuilder.ofByte().asInstanceOf[ArrayBuilder[T]]
      case java.lang.Short.TYPE     => new ArrayBuilder.ofShort().asInstanceOf[ArrayBuilder[T]]
      case java.lang.Character.TYPE => new ArrayBuilder.ofChar().asInstanceOf[ArrayBuilder[T]]
      case java.lang.Integer.TYPE   => new ArrayBuilder.ofInt().asInstanceOf[ArrayBuilder[T]]
      case java.lang.Long.TYPE      => new ArrayBuilder.ofLong().asInstanceOf[ArrayBuilder[T]]
      case java.lang.Float.TYPE     => new ArrayBuilder.ofFloat().asInstanceOf[ArrayBuilder[T]]
      case java.lang.Double.TYPE    => new ArrayBuilder.ofDouble().asInstanceOf[ArrayBuilder[T]]
      case java.lang.Boolean.TYPE   => new ArrayBuilder.ofBoolean().asInstanceOf[ArrayBuilder[T]]
      case java.lang.Void.TYPE      => new ArrayBuilder.ofUnit().asInstanceOf[ArrayBuilder[T]]
      case _                        => new ArrayBuilder.ofRef[T with AnyRef]()(tag.asInstanceOf[ClassTag[T with AnyRef]]).asInstanceOf[ArrayBuilder[T]]
    }
  }

  /** A class for array builders for arrays of reference types.
   *
   *  @tparam T     type of elements for the array builder, subtype of `AnyRef` with a `ClassTag` context bound.
   */
  @deprecatedInheritance("ArrayBuilder.ofRef is an internal implementation not intended for subclassing.", "2.11.0")
  class ofRef[T <: AnyRef : ClassTag] extends ArrayBuilder[T] {

    private var elems: Array[T] = _
    private var capacity: Int = 0
    private var size: Int = 0

    private def mkArray(size: Int): Array[T] = {
      val newelems = new Array[T](size)
      if (this.size > 0) Array.copy(elems, 0, newelems, 0, this.size)
      newelems
    }

    private def resize(size: Int) {
      elems = mkArray(size)
      capacity = size
    }

    override def sizeHint(size: Int) {
      if (capacity < size) resize(size)
    }

    private def ensureSize(size: Int) {
      if (capacity < size || capacity == 0) {
        var newsize = if (capacity == 0) 16 else capacity * 2
        while (newsize < size) newsize *= 2
        resize(newsize)
      }
    }

    def +=(elem: T): this.type = {
      ensureSize(size + 1)
      elems(size) = elem
      size += 1
      this
    }

    override def ++=(xs: TraversableOnce[T]): this.type = (xs.asInstanceOf[AnyRef]) match {
      case xs: WrappedArray.ofRef[_] =>
        ensureSize(this.size + xs.length)
        Array.copy(xs.array, 0, elems, this.size, xs.length)
        size += xs.length
        this
      case _ =>
        super.++=(xs)
    }

    def clear() {
      size = 0
    }

    def result() = {
      if (capacity != 0 && capacity == size) elems
      else mkArray(size)
    }

    override def equals(other: Any): Boolean = other match {
      case x: ofRef[_] => (size == x.size) && (elems == x.elems)
      case _ => false
    }

    override def toString = "ArrayBuilder.ofRef"
  }

  /** A class for array builders for arrays of `byte`s. */
  @deprecatedInheritance("ArrayBuilder.ofByte is an internal implementation not intended for subclassing.", "2.11.0")
  class ofByte extends ArrayBuilder[Byte] {

    private var elems: Array[Byte] = _
    private var capacity: Int = 0
    private var size: Int = 0

    private def mkArray(size: Int): Array[Byte] = {
      val newelems = new Array[Byte](size)
      if (this.size > 0) Array.copy(elems, 0, newelems, 0, this.size)
      newelems
    }

    private def resize(size: Int) {
      elems = mkArray(size)
      capacity = size
    }

    override def sizeHint(size: Int) {
      if (capacity < size) resize(size)
    }

    private def ensureSize(size: Int) {
      if (capacity < size || capacity == 0) {
        var newsize = if (capacity == 0) 16 else capacity * 2
        while (newsize < size) newsize *= 2
        resize(newsize)
      }
    }

    def +=(elem: Byte): this.type = {
      ensureSize(size + 1)
      elems(size) = elem
      size += 1
      this
    }

    override def ++=(xs: TraversableOnce[Byte]): this.type = xs match {
      case xs: WrappedArray.ofByte =>
        ensureSize(this.size + xs.length)
        Array.copy(xs.array, 0, elems, this.size, xs.length)
        size += xs.length
        this
      case _ =>
        super.++=(xs)
    }

    def clear() {
      size = 0
    }

    def result() = {
      if (capacity != 0 && capacity == size) elems
      else mkArray(size)
    }

    override def equals(other: Any): Boolean = other match {
      case x: ofByte => (size == x.size) && (elems == x.elems)
      case _ => false
    }

    override def toString = "ArrayBuilder.ofByte"
  }

  /** A class for array builders for arrays of `short`s. */
  @deprecatedInheritance("ArrayBuilder.ofShort is an internal implementation not intended for subclassing.", "2.11.0")
  class ofShort extends ArrayBuilder[Short] {

    private var elems: Array[Short] = _
    private var capacity: Int = 0
    private var size: Int = 0

    private def mkArray(size: Int): Array[Short] = {
      val newelems = new Array[Short](size)
      if (this.size > 0) Array.copy(elems, 0, newelems, 0, this.size)
      newelems
    }

    private def resize(size: Int) {
      elems = mkArray(size)
      capacity = size
    }

    override def sizeHint(size: Int) {
      if (capacity < size) resize(size)
    }

    private def ensureSize(size: Int) {
      if (capacity < size || capacity == 0) {
        var newsize = if (capacity == 0) 16 else capacity * 2
        while (newsize < size) newsize *= 2
        resize(newsize)
      }
    }

    def +=(elem: Short): this.type = {
      ensureSize(size + 1)
      elems(size) = elem
      size += 1
      this
    }

    override def ++=(xs: TraversableOnce[Short]): this.type = xs match {
      case xs: WrappedArray.ofShort =>
        ensureSize(this.size + xs.length)
        Array.copy(xs.array, 0, elems, this.size, xs.length)
        size += xs.length
        this
      case _ =>
        super.++=(xs)
    }

    def clear() {
      size = 0
    }

    def result() = {
      if (capacity != 0 && capacity == size) elems
      else mkArray(size)
    }

    override def equals(other: Any): Boolean = other match {
      case x: ofShort => (size == x.size) && (elems == x.elems)
      case _ => false
    }

    override def toString = "ArrayBuilder.ofShort"
  }

  /** A class for array builders for arrays of `char`s. */
  @deprecatedInheritance("ArrayBuilder.ofChar is an internal implementation not intended for subclassing.", "2.11.0")
  class ofChar extends ArrayBuilder[Char] {

    private var elems: Array[Char] = _
    private var capacity: Int = 0
    private var size: Int = 0

    private def mkArray(size: Int): Array[Char] = {
      val newelems = new Array[Char](size)
      if (this.size > 0) Array.copy(elems, 0, newelems, 0, this.size)
      newelems
    }

    private def resize(size: Int) {
      elems = mkArray(size)
      capacity = size
    }

    override def sizeHint(size: Int) {
      if (capacity < size) resize(size)
    }

    private def ensureSize(size: Int) {
      if (capacity < size || capacity == 0) {
        var newsize = if (capacity == 0) 16 else capacity * 2
        while (newsize < size) newsize *= 2
        resize(newsize)
      }
    }

    def +=(elem: Char): this.type = {
      ensureSize(size + 1)
      elems(size) = elem
      size += 1
      this
    }

    override def ++=(xs: TraversableOnce[Char]): this.type = xs match {
      case xs: WrappedArray.ofChar =>
        ensureSize(this.size + xs.length)
        Array.copy(xs.array, 0, elems, this.size, xs.length)
        size += xs.length
        this
      case _ =>
        super.++=(xs)
    }

    def clear() {
      size = 0
    }

    def result() = {
      if (capacity != 0 && capacity == size) elems
      else mkArray(size)
    }

    override def equals(other: Any): Boolean = other match {
      case x: ofChar => (size == x.size) && (elems == x.elems)
      case _ => false
    }

    override def toString = "ArrayBuilder.ofChar"
  }

  /** A class for array builders for arrays of `int`s. */
  @deprecatedInheritance("ArrayBuilder.ofInt is an internal implementation not intended for subclassing.", "2.11.0")
  class ofInt extends ArrayBuilder[Int] {

    private var elems: Array[Int] = _
    private var capacity: Int = 0
    private var size: Int = 0

    private def mkArray(size: Int): Array[Int] = {
      val newelems = new Array[Int](size)
      if (this.size > 0) Array.copy(elems, 0, newelems, 0, this.size)
      newelems
    }

    private def resize(size: Int) {
      elems = mkArray(size)
      capacity = size
    }

    override def sizeHint(size: Int) {
      if (capacity < size) resize(size)
    }

    private def ensureSize(size: Int) {
      if (capacity < size || capacity == 0) {
        var newsize = if (capacity == 0) 16 else capacity * 2
        while (newsize < size) newsize *= 2
        resize(newsize)
      }
    }

    def +=(elem: Int): this.type = {
      ensureSize(size + 1)
      elems(size) = elem
      size += 1
      this
    }

    override def ++=(xs: TraversableOnce[Int]): this.type = xs match {
      case xs: WrappedArray.ofInt =>
        ensureSize(this.size + xs.length)
        Array.copy(xs.array, 0, elems, this.size, xs.length)
        size += xs.length
        this
      case _ =>
        super.++=(xs)
    }

    def clear() {
      size = 0
    }

    def result() = {
      if (capacity != 0 && capacity == size) elems
      else mkArray(size)
    }

    override def equals(other: Any): Boolean = other match {
      case x: ofInt => (size == x.size) && (elems == x.elems)
      case _ => false
    }

    override def toString = "ArrayBuilder.ofInt"
  }

  /** A class for array builders for arrays of `long`s. */
  @deprecatedInheritance("ArrayBuilder.ofLong is an internal implementation not intended for subclassing.", "2.11.0")
  class ofLong extends ArrayBuilder[Long] {

    private var elems: Array[Long] = _
    private var capacity: Int = 0
    private var size: Int = 0

    private def mkArray(size: Int): Array[Long] = {
      val newelems = new Array[Long](size)
      if (this.size > 0) Array.copy(elems, 0, newelems, 0, this.size)
      newelems
    }

    private def resize(size: Int) {
      elems = mkArray(size)
      capacity = size
    }

    override def sizeHint(size: Int) {
      if (capacity < size) resize(size)
    }

    private def ensureSize(size: Int) {
      if (capacity < size || capacity == 0) {
        var newsize = if (capacity == 0) 16 else capacity * 2
        while (newsize < size) newsize *= 2
        resize(newsize)
      }
    }

    def +=(elem: Long): this.type = {
      ensureSize(size + 1)
      elems(size) = elem
      size += 1
      this
    }

    override def ++=(xs: TraversableOnce[Long]): this.type = xs match {
      case xs: WrappedArray.ofLong =>
        ensureSize(this.size + xs.length)
        Array.copy(xs.array, 0, elems, this.size, xs.length)
        size += xs.length
        this
      case _ =>
        super.++=(xs)
    }

    def clear() {
      size = 0
    }

    def result() = {
      if (capacity != 0 && capacity == size) elems
      else mkArray(size)
    }

    override def equals(other: Any): Boolean = other match {
      case x: ofLong => (size == x.size) && (elems == x.elems)
      case _ => false
    }

    override def toString = "ArrayBuilder.ofLong"
  }

  /** A class for array builders for arrays of `float`s. */
  @deprecatedInheritance("ArrayBuilder.ofFloat is an internal implementation not intended for subclassing.", "2.11.0")
  class ofFloat extends ArrayBuilder[Float] {

    private var elems: Array[Float] = _
    private var capacity: Int = 0
    private var size: Int = 0

    private def mkArray(size: Int): Array[Float] = {
      val newelems = new Array[Float](size)
      if (this.size > 0) Array.copy(elems, 0, newelems, 0, this.size)
      newelems
    }

    private def resize(size: Int) {
      elems = mkArray(size)
      capacity = size
    }

    override def sizeHint(size: Int) {
      if (capacity < size) resize(size)
    }

    private def ensureSize(size: Int) {
      if (capacity < size || capacity == 0) {
        var newsize = if (capacity == 0) 16 else capacity * 2
        while (newsize < size) newsize *= 2
        resize(newsize)
      }
    }

    def +=(elem: Float): this.type = {
      ensureSize(size + 1)
      elems(size) = elem
      size += 1
      this
    }

    override def ++=(xs: TraversableOnce[Float]): this.type = xs match {
      case xs: WrappedArray.ofFloat =>
        ensureSize(this.size + xs.length)
        Array.copy(xs.array, 0, elems, this.size, xs.length)
        size += xs.length
        this
      case _ =>
        super.++=(xs)
    }

    def clear() {
      size = 0
    }

    def result() = {
      if (capacity != 0 && capacity == size) elems
      else mkArray(size)
    }

    override def equals(other: Any): Boolean = other match {
      case x: ofFloat => (size == x.size) && (elems == x.elems)
      case _ => false
    }

    override def toString = "ArrayBuilder.ofFloat"
  }

  /** A class for array builders for arrays of `double`s. */
  @deprecatedInheritance("ArrayBuilder.ofDouble is an internal implementation not intended for subclassing.", "2.11.0")
  class ofDouble extends ArrayBuilder[Double] {

    private var elems: Array[Double] = _
    private var capacity: Int = 0
    private var size: Int = 0

    private def mkArray(size: Int): Array[Double] = {
      val newelems = new Array[Double](size)
      if (this.size > 0) Array.copy(elems, 0, newelems, 0, this.size)
      newelems
    }

    private def resize(size: Int) {
      elems = mkArray(size)
      capacity = size
    }

    override def sizeHint(size: Int) {
      if (capacity < size) resize(size)
    }

    private def ensureSize(size: Int) {
      if (capacity < size || capacity == 0) {
        var newsize = if (capacity == 0) 16 else capacity * 2
        while (newsize < size) newsize *= 2
        resize(newsize)
      }
    }

    def +=(elem: Double): this.type = {
      ensureSize(size + 1)
      elems(size) = elem
      size += 1
      this
    }

    override def ++=(xs: TraversableOnce[Double]): this.type = xs match {
      case xs: WrappedArray.ofDouble =>
        ensureSize(this.size + xs.length)
        Array.copy(xs.array, 0, elems, this.size, xs.length)
        size += xs.length
        this
      case _ =>
        super.++=(xs)
    }

    def clear() {
      size = 0
    }

    def result() = {
      if (capacity != 0 && capacity == size) elems
      else mkArray(size)
    }

    override def equals(other: Any): Boolean = other match {
      case x: ofDouble => (size == x.size) && (elems == x.elems)
      case _ => false
    }

    override def toString = "ArrayBuilder.ofDouble"
  }

  /** A class for array builders for arrays of `boolean`s. */
  class ofBoolean extends ArrayBuilder[Boolean] {

    private var elems: Array[Boolean] = _
    private var capacity: Int = 0
    private var size: Int = 0

    private def mkArray(size: Int): Array[Boolean] = {
      val newelems = new Array[Boolean](size)
      if (this.size > 0) Array.copy(elems, 0, newelems, 0, this.size)
      newelems
    }

    private def resize(size: Int) {
      elems = mkArray(size)
      capacity = size
    }

    override def sizeHint(size: Int) {
      if (capacity < size) resize(size)
    }

    private def ensureSize(size: Int) {
      if (capacity < size || capacity == 0) {
        var newsize = if (capacity == 0) 16 else capacity * 2
        while (newsize < size) newsize *= 2
        resize(newsize)
      }
    }

    def +=(elem: Boolean): this.type = {
      ensureSize(size + 1)
      elems(size) = elem
      size += 1
      this
    }

    override def ++=(xs: TraversableOnce[Boolean]): this.type = xs match {
      case xs: WrappedArray.ofBoolean =>
        ensureSize(this.size + xs.length)
        Array.copy(xs.array, 0, elems, this.size, xs.length)
        size += xs.length
        this
      case _ =>
        super.++=(xs)
    }

    def clear() {
      size = 0
    }

    def result() = {
      if (capacity != 0 && capacity == size) elems
      else mkArray(size)
    }

    override def equals(other: Any): Boolean = other match {
      case x: ofBoolean => (size == x.size) && (elems == x.elems)
      case _ => false
    }

    override def toString = "ArrayBuilder.ofBoolean"
  }

  /** A class for array builders for arrays of `Unit` type. */
  @deprecatedInheritance("ArrayBuilder.ofUnit is an internal implementation not intended for subclassing.", "2.11.0")
  class ofUnit extends ArrayBuilder[Unit] {

    private var elems: Array[Unit] = _
    private var capacity: Int = 0
    private var size: Int = 0

    private def mkArray(size: Int): Array[Unit] = {
      val newelems = new Array[Unit](size)
      if (this.size > 0) Array.copy(elems, 0, newelems, 0, this.size)
      newelems
    }

    private def resize(size: Int) {
      elems = mkArray(size)
      capacity = size
    }

    override def sizeHint(size: Int) {
      if (capacity < size) resize(size)
    }

    private def ensureSize(size: Int) {
      if (capacity < size || capacity == 0) {
        var newsize = if (capacity == 0) 16 else capacity * 2
        while (newsize < size) newsize *= 2
        resize(newsize)
      }
    }

    def +=(elem: Unit): this.type = {
      ensureSize(size + 1)
      elems(size) = elem
      size += 1
      this
    }

    override def ++=(xs: TraversableOnce[Unit]): this.type = xs match {
      case xs: WrappedArray.ofUnit =>
        ensureSize(this.size + xs.length)
        Array.copy(xs.array, 0, elems, this.size, xs.length)
        size += xs.length
        this
      case _ =>
        super.++=(xs)
    }

    def clear() {
      size = 0
    }

    def result() = {
      if (capacity != 0 && capacity == size) elems
      else mkArray(size)
    }

    override def equals(other: Any): Boolean = other match {
      case x: ofUnit => (size == x.size) && (elems == x.elems)
      case _ => false
    }

    override def toString = "ArrayBuilder.ofUnit"
  }
}