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Standard library for the SubScript extension of the Scala Programming Language
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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2002-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala
package collection
package mutable
import scala.compat.Platform.arraycopy
import scala.reflect.ClassTag
import scala.runtime.ScalaRunTime._
import parallel.mutable.ParArray
/** This class serves as a wrapper for `Array`s with all the operations found in
* indexed sequences. Where needed, instances of arrays are implicitly converted
* into this class.
*
* The difference between this class and `WrappedArray` is that calling transformer
* methods such as `filter` and `map` will yield an array, whereas a `WrappedArray`
* will remain a `WrappedArray`.
*
* @since 2.8
*
* @tparam T type of the elements contained in this array.
*
* @define Coll `Array`
* @define orderDependent
* @define orderDependentFold
* @define mayNotTerminateInf
* @define willNotTerminateInf
*/
@deprecatedInheritance("ArrayOps will be sealed to facilitate greater flexibility with array/collections integration in future releases.", "2.11.0")
trait ArrayOps[T] extends Any with ArrayLike[T, Array[T]] with CustomParallelizable[T, ParArray[T]] {
private def elementClass: Class[_] =
arrayElementClass(repr.getClass)
override def copyToArray[U >: T](xs: Array[U], start: Int, len: Int) {
var l = math.min(len, repr.length)
if (xs.length - start < l) l = xs.length - start max 0
Array.copy(repr, 0, xs, start, l)
}
override def toArray[U >: T : ClassTag]: Array[U] = {
val thatElementClass = arrayElementClass(implicitly[ClassTag[U]])
if (elementClass eq thatElementClass)
repr.asInstanceOf[Array[U]]
else
super.toArray[U]
}
def :+[B >: T: ClassTag](elem: B): Array[B] = {
val result = Array.ofDim[B](repr.length + 1)
Array.copy(repr, 0, result, 0, repr.length)
result(repr.length) = elem
result
}
def +:[B >: T: ClassTag](elem: B): Array[B] = {
val result = Array.ofDim[B](repr.length + 1)
result(0) = elem
Array.copy(repr, 0, result, 1, repr.length)
result
}
override def par = ParArray.handoff(repr)
/** Flattens a two-dimensional array by concatenating all its rows
* into a single array.
*
* @tparam U Type of row elements.
* @param asTrav A function that converts elements of this array to rows - arrays of type `U`.
* @return An array obtained by concatenating rows of this array.
*/
def flatten[U](implicit asTrav: T => scala.collection.Traversable[U], m: ClassTag[U]): Array[U] = {
val b = Array.newBuilder[U]
b.sizeHint(map{case is: scala.collection.IndexedSeq[_] => is.size case _ => 0}.sum)
for (xs <- this)
b ++= asTrav(xs)
b.result()
}
/** Transposes a two dimensional array.
*
* @tparam U Type of row elements.
* @param asArray A function that converts elements of this array to rows - arrays of type `U`.
* @return An array obtained by replacing elements of this arrays with rows the represent.
*/
def transpose[U](implicit asArray: T => Array[U]): Array[Array[U]] = {
val bb: Builder[Array[U], Array[Array[U]]] = Array.newBuilder(ClassTag[Array[U]](elementClass))
if (isEmpty) bb.result()
else {
def mkRowBuilder() = Array.newBuilder(ClassTag[U](arrayElementClass(elementClass)))
val bs = asArray(head) map (_ => mkRowBuilder())
for (xs <- this) {
var i = 0
for (x <- asArray(xs)) {
bs(i) += x
i += 1
}
}
for (b <- bs) bb += b.result()
bb.result()
}
}
/** Converts an array of pairs into an array of first elements and an array of second elements.
*
* @tparam T1 the type of the first half of the element pairs
* @tparam T2 the type of the second half of the element pairs
* @param asPair an implicit conversion which asserts that the element type
* of this Array is a pair.
* @param ct1 a class tag for T1 type parameter that is required to create an instance
* of Array[T1]
* @param ct2 a class tag for T2 type parameter that is required to create an instance
* of Array[T2]
* @return a pair of Arrays, containing, respectively, the first and second half
* of each element pair of this Array.
*/
// implementation NOTE: ct1 and ct2 can't be written as context bounds because desugared
// implicits are put in front of asPair parameter that is supposed to guide type inference
def unzip[T1, T2](implicit asPair: T => (T1, T2), ct1: ClassTag[T1], ct2: ClassTag[T2]): (Array[T1], Array[T2]) = {
val a1 = new Array[T1](length)
val a2 = new Array[T2](length)
var i = 0
while (i < length) {
val e = apply(i)
a1(i) = e._1
a2(i) = e._2
i += 1
}
(a1, a2)
}
/** Converts an array of triples into three arrays, one containing the elements from each position of the triple.
*
* @tparam T1 the type of the first of three elements in the triple
* @tparam T2 the type of the second of three elements in the triple
* @tparam T3 the type of the third of three elements in the triple
* @param asTriple an implicit conversion which asserts that the element type
* of this Array is a triple.
* @param ct1 a class tag for T1 type parameter that is required to create an instance
* of Array[T1]
* @param ct2 a class tag for T2 type parameter that is required to create an instance
* of Array[T2]
* @param ct3 a class tag for T3 type parameter that is required to create an instance
* of Array[T3]
* @return a triple of Arrays, containing, respectively, the first, second, and third
* elements from each element triple of this Array.
*/
// implementation NOTE: ct1, ct2, ct3 can't be written as context bounds because desugared
// implicits are put in front of asPair parameter that is supposed to guide type inference
def unzip3[T1, T2, T3](implicit asTriple: T => (T1, T2, T3), ct1: ClassTag[T1], ct2: ClassTag[T2],
ct3: ClassTag[T3]): (Array[T1], Array[T2], Array[T3]) = {
val a1 = new Array[T1](length)
val a2 = new Array[T2](length)
val a3 = new Array[T3](length)
var i = 0
while (i < length) {
val e = apply(i)
a1(i) = e._1
a2(i) = e._2
a3(i) = e._3
i += 1
}
(a1, a2, a3)
}
def seq = thisCollection
}
/**
* A companion object for `ArrayOps`.
*
* @since 2.8
*/
object ArrayOps {
/** A class of `ArrayOps` for arrays containing reference types. */
final class ofRef[T <: AnyRef](override val repr: Array[T]) extends AnyVal with ArrayOps[T] with ArrayLike[T, Array[T]] {
override protected[this] def thisCollection: WrappedArray[T] = new WrappedArray.ofRef[T](repr)
override protected[this] def toCollection(repr: Array[T]): WrappedArray[T] = new WrappedArray.ofRef[T](repr)
override protected[this] def newBuilder = new ArrayBuilder.ofRef[T]()(ClassTag[T](arrayElementClass(repr.getClass)))
def length: Int = repr.length
def apply(index: Int): T = repr(index)
def update(index: Int, elem: T) { repr(index) = elem }
}
/** A class of `ArrayOps` for arrays containing `byte`s. */
final class ofByte(override val repr: Array[Byte]) extends AnyVal with ArrayOps[Byte] with ArrayLike[Byte, Array[Byte]] {
override protected[this] def thisCollection: WrappedArray[Byte] = new WrappedArray.ofByte(repr)
override protected[this] def toCollection(repr: Array[Byte]): WrappedArray[Byte] = new WrappedArray.ofByte(repr)
override protected[this] def newBuilder = new ArrayBuilder.ofByte
def length: Int = repr.length
def apply(index: Int): Byte = repr(index)
def update(index: Int, elem: Byte) { repr(index) = elem }
}
/** A class of `ArrayOps` for arrays containing `short`s. */
final class ofShort(override val repr: Array[Short]) extends AnyVal with ArrayOps[Short] with ArrayLike[Short, Array[Short]] {
override protected[this] def thisCollection: WrappedArray[Short] = new WrappedArray.ofShort(repr)
override protected[this] def toCollection(repr: Array[Short]): WrappedArray[Short] = new WrappedArray.ofShort(repr)
override protected[this] def newBuilder = new ArrayBuilder.ofShort
def length: Int = repr.length
def apply(index: Int): Short = repr(index)
def update(index: Int, elem: Short) { repr(index) = elem }
}
/** A class of `ArrayOps` for arrays containing `char`s. */
final class ofChar(override val repr: Array[Char]) extends AnyVal with ArrayOps[Char] with ArrayLike[Char, Array[Char]] {
override protected[this] def thisCollection: WrappedArray[Char] = new WrappedArray.ofChar(repr)
override protected[this] def toCollection(repr: Array[Char]): WrappedArray[Char] = new WrappedArray.ofChar(repr)
override protected[this] def newBuilder = new ArrayBuilder.ofChar
def length: Int = repr.length
def apply(index: Int): Char = repr(index)
def update(index: Int, elem: Char) { repr(index) = elem }
}
/** A class of `ArrayOps` for arrays containing `int`s. */
final class ofInt(override val repr: Array[Int]) extends AnyVal with ArrayOps[Int] with ArrayLike[Int, Array[Int]] {
override protected[this] def thisCollection: WrappedArray[Int] = new WrappedArray.ofInt(repr)
override protected[this] def toCollection(repr: Array[Int]): WrappedArray[Int] = new WrappedArray.ofInt(repr)
override protected[this] def newBuilder = new ArrayBuilder.ofInt
def length: Int = repr.length
def apply(index: Int): Int = repr(index)
def update(index: Int, elem: Int) { repr(index) = elem }
}
/** A class of `ArrayOps` for arrays containing `long`s. */
final class ofLong(override val repr: Array[Long]) extends AnyVal with ArrayOps[Long] with ArrayLike[Long, Array[Long]] {
override protected[this] def thisCollection: WrappedArray[Long] = new WrappedArray.ofLong(repr)
override protected[this] def toCollection(repr: Array[Long]): WrappedArray[Long] = new WrappedArray.ofLong(repr)
override protected[this] def newBuilder = new ArrayBuilder.ofLong
def length: Int = repr.length
def apply(index: Int): Long = repr(index)
def update(index: Int, elem: Long) { repr(index) = elem }
}
/** A class of `ArrayOps` for arrays containing `float`s. */
final class ofFloat(override val repr: Array[Float]) extends AnyVal with ArrayOps[Float] with ArrayLike[Float, Array[Float]] {
override protected[this] def thisCollection: WrappedArray[Float] = new WrappedArray.ofFloat(repr)
override protected[this] def toCollection(repr: Array[Float]): WrappedArray[Float] = new WrappedArray.ofFloat(repr)
override protected[this] def newBuilder = new ArrayBuilder.ofFloat
def length: Int = repr.length
def apply(index: Int): Float = repr(index)
def update(index: Int, elem: Float) { repr(index) = elem }
}
/** A class of `ArrayOps` for arrays containing `double`s. */
final class ofDouble(override val repr: Array[Double]) extends AnyVal with ArrayOps[Double] with ArrayLike[Double, Array[Double]] {
override protected[this] def thisCollection: WrappedArray[Double] = new WrappedArray.ofDouble(repr)
override protected[this] def toCollection(repr: Array[Double]): WrappedArray[Double] = new WrappedArray.ofDouble(repr)
override protected[this] def newBuilder = new ArrayBuilder.ofDouble
def length: Int = repr.length
def apply(index: Int): Double = repr(index)
def update(index: Int, elem: Double) { repr(index) = elem }
}
/** A class of `ArrayOps` for arrays containing `boolean`s. */
final class ofBoolean(override val repr: Array[Boolean]) extends AnyVal with ArrayOps[Boolean] with ArrayLike[Boolean, Array[Boolean]] {
override protected[this] def thisCollection: WrappedArray[Boolean] = new WrappedArray.ofBoolean(repr)
override protected[this] def toCollection(repr: Array[Boolean]): WrappedArray[Boolean] = new WrappedArray.ofBoolean(repr)
override protected[this] def newBuilder = new ArrayBuilder.ofBoolean
def length: Int = repr.length
def apply(index: Int): Boolean = repr(index)
def update(index: Int, elem: Boolean) { repr(index) = elem }
}
/** A class of `ArrayOps` for arrays of `Unit` types. */
final class ofUnit(override val repr: Array[Unit]) extends AnyVal with ArrayOps[Unit] with ArrayLike[Unit, Array[Unit]] {
override protected[this] def thisCollection: WrappedArray[Unit] = new WrappedArray.ofUnit(repr)
override protected[this] def toCollection(repr: Array[Unit]): WrappedArray[Unit] = new WrappedArray.ofUnit(repr)
override protected[this] def newBuilder = new ArrayBuilder.ofUnit
def length: Int = repr.length
def apply(index: Int): Unit = repr(index)
def update(index: Int, elem: Unit) { repr(index) = elem }
}
}