Combiner

scala.collection.parallel.Combiner
trait Combiner[-Elem, +To] extends Builder[Elem, To], Sizing, Parallel

The base trait for all combiners. A combiner incremental collection construction just like a regular builder, but also implements an efficient merge operation of two builders via combine method. Once the collection is constructed, it may be obtained by invoking the result method.

The complexity of the combine method should be less than linear for best performance. The result method doesn't have to be a constant time operation, but may be performed in parallel.

Type parameters

Elem

the type of the elements added to the builder

To

the type of the collection the builder produces

Attributes

Graph
Supertypes
trait Parallel
trait Sizing
trait Builder[Elem, To]
trait Growable[Elem]
trait Clearable
class Object
trait Matchable
class Any
Show all
Known subtypes
trait LazyCombiner[Elem, To, Buff]

Members list

Value members

Abstract methods

def combine[N <: Elem, NewTo >: To](other: Combiner[N, NewTo]): Combiner[N, NewTo]

Combines the contents of the receiver builder and the other builder, producing a new builder containing both their elements.

Combines the contents of the receiver builder and the other builder, producing a new builder containing both their elements.

This method may combine the two builders by copying them into a larger collection, by producing a lazy view that gets evaluated once result is invoked, or use a merge operation specific to the data structure in question.

Note that both the receiver builder and other builder become invalidated after the invocation of this method, and should be cleared (see clear) if they are to be used again.

Also, combining two combiners c1 and c2 for which c1 eq c2 is true, that is, they are the same objects in memory:

c1.combine(c2)

always does nothing and returns c1.

Type parameters

N

the type of elements contained by the other builder

NewTo

the type of collection produced by the other builder

Value parameters

other

the other builder

Attributes

Returns

the parallel builder containing both the elements of this and the other builder

Concrete methods

Returns true if this combiner has a thread-safe += and is meant to be shared across several threads constructing the collection.

Returns true if this combiner has a thread-safe += and is meant to be shared across several threads constructing the collection.

By default, this method returns false.

Attributes

def fromSequential(seq: IterableOnce[Elem]): To

Add all elements from a sequential collection and return the result.

Add all elements from a sequential collection and return the result.

Attributes

Constructs the result and sets the appropriate tasksupport object to the resulting collection if this is applicable.

Constructs the result and sets the appropriate tasksupport object to the resulting collection if this is applicable.

Attributes

Inherited methods

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

Attributes

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

Attributes

Inherited from:
Growable
def addAll(elems: IterableOnce[Elem]): Growable.this.type

Attributes

Inherited from:
Growable
def knownSize: Int

Attributes

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

Attributes

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

Attributes

Inherited from:
Builder

Attributes

Inherited from:
Builder

Attributes

Inherited from:
Builder

Inherited and Abstract methods

def addOne(elem: Elem): Growable.this.type

Attributes

Inherited from:
Growable
def clear(): Unit

Attributes

Inherited from:
Builder
def result(): To

Attributes

Inherited from:
Builder
def size: Int

Attributes

Inherited from:
Sizing

Deprecated and Inherited methods

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

Attributes

Deprecated
[Since version 2.13.0] Use `++=` aka `addAll` instead of varargs `+=`; infix operations with an operand of multiple args will be deprecated
Inherited from:
Growable

Concrete fields