GrowableBuilder

scala.collection.mutable.GrowableBuilder
class GrowableBuilder[Elem, To <: Growable[Elem]](val elems: To) extends Builder[Elem, To]

The canonical builder for collections that are growable, i.e. that support an efficient += method which adds an element to the collection.

GrowableBuilders can produce only a single instance of the collection they are growing.

Attributes

Source
GrowableBuilder.scala
Graph
Supertypes
trait Builder[Elem, To]
trait Growable[Elem]
trait Clearable
class Object
trait Matchable
class Any
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Members list

Keywords
  • no keywords
  • final
  • override
Inherited
  • Not inherited
  • Builder
  • Growable

Value members

Concrete methods

override def addAll(xs: IterableOnce[Elem]): this.type

Adds all elements produced by an IterableOnce to this growing builder.

Adds all elements produced by an IterableOnce to this growing builder.

Value parameters

elems

the IterableOnce producing the elements to add.

Attributes

Returns

the growing builder itself.

Definition Classes
Source
GrowableBuilder.scala
def addOne(elem: Elem): this.type

Adds a single element to this growing builder.

Adds a single element to this growing builder.

Value parameters

elem

the element to add.

Attributes

Returns

the growing builder itself

Source
GrowableBuilder.scala
def clear(): Unit

Clears the contents of this builder.

Clears the contents of this builder. After execution of this method the builder will contain no elements.

Attributes

Source
GrowableBuilder.scala
override def knownSize: Int

The number of elements in the collection under construction, if it can be cheaply computed, -1 otherwise.

The number of elements in the collection under construction, if it can be cheaply computed, -1 otherwise.

Attributes

Returns

The number of elements. The default implementation always returns -1.

Definition Classes
Source
GrowableBuilder.scala
def result(): To

Result collection consisting of all elements appended so far.

Result collection consisting of all elements appended so far.

Attributes

Source
GrowableBuilder.scala

Inherited methods

final def ++=(elems: IterableOnce[Elem]): Growable.this.type

Alias for addAll

Alias for addAll

Attributes

Inherited from:
Growable
Source
Growable.scala
final def +=(elem: Elem): Growable.this.type

Alias for addOne

Alias for addOne

Attributes

Inherited from:
Growable
Source
Growable.scala
def mapResult[NewTo](f: To => NewTo): Builder[Elem, NewTo]

A builder resulting from this builder my mapping the result using f.

A builder resulting from this builder my mapping the result using f.

Attributes

Inherited from:
Builder
Source
Builder.scala
final def sizeHint(coll: IterableOnce[_], delta: Int): Unit

Gives a hint that the result of this builder is expected to have the same size as the given collection, plus some delta.

Gives a hint that the result of this builder is expected to have the same size as the given collection, plus some delta.

This method provides a hint only if the collection has a known size, as specified by the following pseudocode:

if (coll.knownSize != -1)
  if (coll.knownSize + delta <= 0) sizeHint(0)
  else sizeHint(coll.knownSize + delta)

If the delta is negative and the result size is known to be negative, then the size hint is issued at zero.

Some builder classes will optimize their representation based on the hint. However, builder implementations are required to work correctly even if the hint is wrong, i.e., if a different number of elements is added.

Value parameters

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 (zero if omitted).

Attributes

Inherited from:
Builder
Source
Builder.scala
def sizeHint(size: Int): Unit

Gives a hint how many elements are expected to be added in total by the time result is called.

Gives a hint how many elements are expected to be added in total by the time result is called.

Some builder classes will optimize their representation based on the hint. However, builder implementations are required to work correctly even if the hint is wrong, e.g., a different number of elements is added, or the hint is out of range.

The default implementation simply ignores the hint.

Value parameters

size

the hint how many elements will be added.

Attributes

Inherited from:
Builder
Source
Builder.scala
final def sizeHintBounded(size: Int, boundingColl: Iterable[_]): 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.

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.

Value parameters

boundingColl

the bounding collection. If it is an IndexedSeqLike, then sizes larger than collection's size are reduced.

size

the hint how many elements will be added.

Attributes

Inherited from:
Builder
Source
Builder.scala

Deprecated and Inherited methods

final def +=(elem1: Elem, elem2: Elem, elems: Elem*): Growable.this.type

Adds two or more elements to this growable collection.

Adds two or more elements to this growable collection.

Value parameters

elem1

the first element to add.

elem2

the second element to add.

elems

the remaining elements to add.

Attributes

Returns

the growable collection itself

Deprecated
true
Inherited from:
Growable
Source
Growable.scala