scala.collection.mutable.ArrayBuilder
abstract class ArrayBuilder [ T ] extends ReusableBuilder [ T , Array [ T ]] with Serializable
A builder class for arrays.
T
the type of the elements for the builder.
Source
Since
Concrete Value Members From scala.collection.generic.Growable
def ++=(xs: TraversableOnce[T]): ArrayBuilder.this.type
adds all elements produced by a TraversableOnce to this growable collection.
xs
the TraversableOnce producing the elements to add.
returns
the growable collection itself.
Definition Classes
(defined at scala.collection.generic.Growable)
def +=(elem1: T, elem2: T, elems: T*): ArrayBuilder.this.type
adds two or more elements to this growable collection.
elem1
the first element to add.
elem2
the second element to add.
elems
the remaining elements to add.
returns
the growable collection itself
Definition Classes
(defined at scala.collection.generic.Growable)
Instance Constructors From scala.collection.mutable.ArrayBuilder
new ArrayBuilder()
(defined at scala.collection.mutable.ArrayBuilder)
Abstract Value Members From scala.collection.mutable.Builder
abstract def +=(elem: T): ArrayBuilder.this.type
Adds a single element to the builder.
elem
returns
Definition Classes
(defined at scala.collection.mutable.Builder)
Concrete Value Members From scala.collection.mutable.Builder
def mapResult[NewTo](f: (Array[T]) ⇒ NewTo): Builder[T, NewTo]
Creates a new builder by applying a transformation function to the results of
this builder.
NewTo
the type of collection returned by f
.
f
the transformation function.
returns
a new builder which is the same as the current builder except that a
transformation function is applied to this builder’s result.
Definition Classes
Note
The original builder should no longer be used after mapResult
is called.
(defined at scala.collection.mutable.Builder)
def sizeHint(size: Int): Unit
Gives a hint how many elements are expected to be added when the next result
is called. Some builder classes will optimize their representation based on the
hint. However, builder implementations are still required to work correctly even
if the hint is wrong, i.e. a different number of elements is added.
size
the hint how many elements will be added.
Definition Classes
(defined at scala.collection.mutable.Builder)
def sizeHint(coll: TraversableLike[_, _]): Unit
Gives a hint that one expects the result
of this builder to have the same size
as the given collection, plus some delta. This will provide a hint only if the
collection is known to have a cheap size
method. Currently this is assumed to
be the case if and only if the collection is of type IndexedSeqLike
. Some
builder classes will optimize their representation based on the hint. However,
builder implementations are still required to work correctly even if the hint is
wrong, i.e. a different number of elements is added.
coll
the collection which serves as a hint for the result’s size.
Definition Classes
(defined at scala.collection.mutable.Builder)
def sizeHint(coll: TraversableLike[_, _], delta: Int): Unit
Gives a hint that one expects the result
of this builder to have the same size
as the given collection, plus some delta. This will provide a hint only if the
collection is known to have a cheap size
method. Currently this is assumed to
be the case if and only if the collection is of type IndexedSeqLike
. Some
builder classes will optimize their representation based on the hint. However,
builder implementations are still required to work correctly even if the hint is
wrong, i.e. a different number of elements is added.
coll
the collection which serves as a hint for the result’s size.
delta
a correction to add to the coll.size
to produce the size hint.
Definition Classes
(defined at scala.collection.mutable.Builder)
def sizeHintBounded(size: Int, boundingColl: TraversableLike[_, _]): Unit
Gives a hint how many elements are expected to be added when the next result
is called, together with an upper bound given by the size of some other
collection. Some builder classes will optimize their representation based on the
hint. However, builder implementations are still required to work correctly even
if the hint is wrong, i.e. a different number of elements is added.
size
the hint how many elements will be added.
boundingColl
the bounding collection. If it is an IndexedSeqLike, then sizes larger than
collection’s size are reduced.
Definition Classes
(defined at scala.collection.mutable.Builder)
Abstract Value Members From scala.collection.mutable.ReusableBuilder
abstract def result(): Array[T]
Produces a collection from the added elements.
After a call to result
, the behavior of all other methods is undefined save
for clear
. If clear
is called, then the builder is reset and may be used to
build another instance.
returns
a collection containing the elements added to this builder.
Definition Classes
ReusableBuilder → Builder
(defined at scala.collection.mutable.ReusableBuilder)
Concrete Value Members From scala.collection.mutable.ReusableBuilder
abstract def clear(): Unit
Clears the contents of this builder. After execution of this method, the builder
will contain no elements.
If executed immediately after a call to result
, this allows a new instance of
the same type of collection to be built.
Definition Classes
ReusableBuilder → Builder → Growable → Clearable
(defined at scala.collection.mutable.ReusableBuilder)
Full Source:
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala
package collection
package mutable
import scala.reflect.ClassTag
/** A builder class for arrays.
*
* @since 2.8
*
* @tparam T the type of the elements for the builder.
*/
abstract class ArrayBuilder [ T ] extends ReusableBuilder [ 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.
*
* This builder can be reused.
*
* @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 ) {
capacity = 0
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. It can be reused. */
@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 ) {
capacity = 0
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. It can be reused. */
@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 ) {
capacity = 0
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. It can be reused. */
@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 ) {
capacity = 0
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. It can be reused. */
@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 ) {
capacity = 0
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. It can be reused. */
@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 ) {
capacity = 0
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. It can be reused. */
@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 ) {
capacity = 0
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. It can be reused. */
@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 ) {
capacity = 0
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. It can be reused. */
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 ) {
capacity = 0
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. It can be reused. */
@deprecatedInheritance ( "ArrayBuilder.ofUnit is an internal implementation not intended for subclassing." , "2.11.0" )
class ofUnit extends ArrayBuilder [ Unit ] {
private var size : Int = 0
def +=( elem : Unit ) : this. type = {
size += 1
this
}
override def ++=( xs : TraversableOnce [ Unit ]) : this. type = {
size += xs . size
this
}
def clear () { size = 0 }
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
}
override def toString = "ArrayBuilder.ofUnit"
}
}