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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2002-2010, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala.collection
package mutable
import scala.reflect.ClassManifest
/** 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
*
* @define Coll ArrayOps
*/
abstract class ArrayOps[T] extends ArrayLike[T, Array[T]] {
private def rowBuilder[U]: Builder[U, Array[U]] =
Array.newBuilder(
ClassManifest.fromClass(
repr.getClass.getComponentType.getComponentType.asInstanceOf[Predef.Class[U]]))
override def toArray[U >: T : ClassManifest]: Array[U] =
if (implicitly[ClassManifest[U]].erasure eq repr.getClass.getComponentType)
repr.asInstanceOf[Array[U]]
else
super.toArray[U]
/** Flattens a two-dimensional array by concatenating all its rows
* into a single 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 concatenating rows of this array.
*/
def flatten[U](implicit asArray: T => /*<:<!!!*/ Array[U]): Array[U] = {
val b = rowBuilder[U]
for (xs <- this)
b ++= asArray(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 bs = asArray(head) map (_ => rowBuilder[U])
for (xs <- this) {
var i = 0
for (x <- asArray(xs)) {
bs(i) += x
i += 1
}
}
val bb: Builder[Array[U], Array[Array[U]]] = Array.newBuilder(
ClassManifest.fromClass(
repr.getClass.getComponentType.asInstanceOf[Predef.Class[Array[U]]]))
for (b <- bs) bb += b.result
bb.result
}
}
/**
* A companion object for `ArrayOps`.
*
* @since 2.8
*/
object ArrayOps {
/** A class of `ArrayOps` for arrays containing reference types. */
class ofRef[T <: AnyRef](override val repr: Array[T]) extends 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]()(
ClassManifest.classType[T](repr.getClass.getComponentType))
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. */
class ofByte(override val repr: Array[Byte]) extends 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. */
class ofShort(override val repr: Array[Short]) extends 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. */
class ofChar(override val repr: Array[Char]) extends 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. */
class ofInt(override val repr: Array[Int]) extends 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. */
class ofLong(override val repr: Array[Long]) extends 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. */
class ofFloat(override val repr: Array[Float]) extends 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. */
class ofDouble(override val repr: Array[Double]) extends 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. */
class ofBoolean(override val repr: Array[Boolean]) extends 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. */
class ofUnit(override val repr: Array[Unit]) extends 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 }
}
}
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