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Standard library for the Scala Programming Language
/*
* 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.collection
package mutable
import scala.reflect.ClassTag
/** A builder class for arrays.
*
* @tparam T the type of the elements for the builder.
*/
@SerialVersionUID(3L)
sealed abstract class ArrayBuilder[T]
extends ReusableBuilder[T, Array[T]]
with Serializable {
protected[this] var capacity: Int = 0
protected[this] def elems: Array[T]
protected var size: Int = 0
def length: Int = size
override def knownSize: Int = size
protected[this] final def ensureSize(size: Int): Unit = {
if (capacity < size || capacity == 0) {
var newsize = if (capacity == 0) 16 else capacity * 2
while (newsize < size) newsize *= 2
resize(newsize)
}
}
override final def sizeHint(size: Int): Unit =
if (capacity < size) resize(size)
def clear(): Unit = size = 0
protected[this] def resize(size: Int): Unit
/** Add all elements of an array */
def addAll(xs: Array[_ <: T]): this.type = addAll(xs, 0, xs.length)
/** Add a slice of an array */
def addAll(xs: Array[_ <: T], offset: Int, length: Int): this.type = {
ensureSize(this.size + length)
Array.copy(xs, offset, elems, this.size, length)
size += length
this
}
override def addAll(xs: IterableOnce[T]): this.type = {
val k = xs.knownSize
if (k > 0) {
ensureSize(this.size + k)
IterableOnce.copyElemsToArray(xs, elems, this.size)
size += k
} else if (k < 0) super.addAll(xs)
this
}
}
/** A companion object for array builders.
*/
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.
*/
@inline 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.
*
* This builder can be reused.
*
* @tparam T type of elements for the array builder, subtype of `AnyRef` with a `ClassTag` context bound.
*/
@SerialVersionUID(3L)
final class ofRef[T <: AnyRef](implicit ct: ClassTag[T]) extends ArrayBuilder[T] {
protected var elems: Array[T] = _
private def mkArray(size: Int): Array[T] = {
if (capacity == size && capacity > 0) elems
else if (elems eq null) new Array[T](size)
else java.util.Arrays.copyOf[T](elems, size)
}
protected[this] def resize(size: Int): Unit = {
elems = mkArray(size)
capacity = size
}
def addOne(elem: T): this.type = {
ensureSize(size + 1)
elems(size) = elem
size += 1
this
}
def result(): Array[T] = {
if (capacity != 0 && capacity == size) {
capacity = 0
val res = elems
elems = null
res
}
else mkArray(size)
}
override def clear(): Unit = {
super.clear()
if(elems ne null) java.util.Arrays.fill(elems.asInstanceOf[Array[AnyRef]], null)
}
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. It can be reused. */
@SerialVersionUID(3L)
final class ofByte extends ArrayBuilder[Byte] {
protected var elems: Array[Byte] = _
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
}
protected[this] def resize(size: Int): Unit = {
elems = mkArray(size)
capacity = size
}
def addOne(elem: Byte): this.type = {
ensureSize(size + 1)
elems(size) = elem
size += 1
this
}
def result(): Array[Byte] = {
if (capacity != 0 && capacity == size) {
capacity = 0
val res = elems
elems = null
res
}
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. It can be reused. */
@SerialVersionUID(3L)
final class ofShort extends ArrayBuilder[Short] {
protected var elems: Array[Short] = _
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
}
protected[this] def resize(size: Int): Unit = {
elems = mkArray(size)
capacity = size
}
def addOne(elem: Short): this.type = {
ensureSize(size + 1)
elems(size) = elem
size += 1
this
}
def result(): Array[Short] = {
if (capacity != 0 && capacity == size) {
capacity = 0
val res = elems
elems = null
res
}
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. It can be reused. */
@SerialVersionUID(3L)
final class ofChar extends ArrayBuilder[Char] {
protected var elems: Array[Char] = _
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
}
protected[this] def resize(size: Int): Unit = {
elems = mkArray(size)
capacity = size
}
def addOne(elem: Char): this.type = {
ensureSize(size + 1)
elems(size) = elem
size += 1
this
}
def result(): Array[Char] = {
if (capacity != 0 && capacity == size) {
capacity = 0
val res = elems
elems = null
res
}
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. It can be reused. */
@SerialVersionUID(3L)
final class ofInt extends ArrayBuilder[Int] {
protected var elems: Array[Int] = _
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
}
protected[this] def resize(size: Int): Unit = {
elems = mkArray(size)
capacity = size
}
def addOne(elem: Int): this.type = {
ensureSize(size + 1)
elems(size) = elem
size += 1
this
}
def result(): Array[Int] = {
if (capacity != 0 && capacity == size) {
capacity = 0
val res = elems
elems = null
res
}
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. It can be reused. */
@SerialVersionUID(3L)
final class ofLong extends ArrayBuilder[Long] {
protected var elems: Array[Long] = _
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
}
protected[this] def resize(size: Int): Unit = {
elems = mkArray(size)
capacity = size
}
def addOne(elem: Long): this.type = {
ensureSize(size + 1)
elems(size) = elem
size += 1
this
}
def result(): Array[Long] = {
if (capacity != 0 && capacity == size) {
capacity = 0
val res = elems
elems = null
res
}
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. It can be reused. */
@SerialVersionUID(3L)
final class ofFloat extends ArrayBuilder[Float] {
protected var elems: Array[Float] = _
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
}
protected[this] def resize(size: Int): Unit = {
elems = mkArray(size)
capacity = size
}
def addOne(elem: Float): this.type = {
ensureSize(size + 1)
elems(size) = elem
size += 1
this
}
def result(): Array[Float] = {
if (capacity != 0 && capacity == size) {
capacity = 0
val res = elems
elems = null
res
}
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. It can be reused. */
@SerialVersionUID(3L)
final class ofDouble extends ArrayBuilder[Double] {
protected var elems: Array[Double] = _
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
}
protected[this] def resize(size: Int): Unit = {
elems = mkArray(size)
capacity = size
}
def addOne(elem: Double): this.type = {
ensureSize(size + 1)
elems(size) = elem
size += 1
this
}
def result(): Array[Double] = {
if (capacity != 0 && capacity == size) {
capacity = 0
val res = elems
elems = null
res
}
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. It can be reused. */
@SerialVersionUID(3L)
class ofBoolean extends ArrayBuilder[Boolean] {
protected var elems: Array[Boolean] = _
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
}
protected[this] def resize(size: Int): Unit = {
elems = mkArray(size)
capacity = size
}
def addOne(elem: Boolean): this.type = {
ensureSize(size + 1)
elems(size) = elem
size += 1
this
}
def result(): Array[Boolean] = {
if (capacity != 0 && capacity == size) {
capacity = 0
val res = elems
elems = null
res
}
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. It can be reused. */
@SerialVersionUID(3L)
final class ofUnit extends ArrayBuilder[Unit] {
protected def elems: Array[Unit] = throw new UnsupportedOperationException()
def addOne(elem: Unit): this.type = {
size += 1
this
}
override def addAll(xs: IterableOnce[Unit]): this.type = {
size += xs.iterator.size
this
}
override def addAll(xs: Array[_ <: Unit], offset: Int, length: Int): this.type = {
size += length
this
}
def result() = {
val ans = new Array[Unit](size)
var i = 0
while (i < size) { ans(i) = (); i += 1 }
ans
}
override def equals(other: Any): Boolean = other match {
case x: ofUnit => (size == x.size)
case _ => false
}
protected[this] def resize(size: Int): Unit = ()
override def toString = "ArrayBuilder.ofUnit"
}
}