Test two objects for inequality.
true
if !(this == that), false otherwise.
Equivalent to x.hashCode
except for boxed numeric types and null
. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null
returns a hashcode where null.hashCode
throws a NullPointerException
.
a hash value consistent with ==
The expression x == that
is equivalent to if (x eq null) that eq null else x.equals(that)
.
true
if the receiver object is equivalent to the argument; false
otherwise.
Cast the receiver object to be of type T0
.
Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String]
will throw a ClassCastException
at runtime, while the expression List(1).asInstanceOf[List[String]]
will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.
the receiver object.
ClassCastException
if the receiver object is not an instance of the erasure of type T0
.
Create a copy of the receiver object.
The default implementation of the clone
method is platform dependent.
a copy of the receiver object.
Tests whether the argument (that
) is a reference to the receiver object (this
).
The eq
method implements an equivalence relation on non-null instances of AnyRef
, and has three additional properties:
x
and y
of type AnyRef
, multiple invocations of x.eq(y)
consistently returns true
or consistently returns false
.For any non-null instance x
of type AnyRef
, x.eq(null)
and null.eq(x)
returns false
.
null.eq(null)
returns true
. When overriding the equals
or hashCode
methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2
), they should be equal to each other (o1 == o2
) and they should hash to the same value (o1.hashCode == o2.hashCode
).
true
if the argument is a reference to the receiver object; false
otherwise.
The equality method for reference types. Default implementation delegates to eq
.
See also equals
in scala.Any.
true
if the receiver object is equivalent to the argument; false
otherwise.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize
method is invoked, as well as the interaction between finalize
and non-local returns and exceptions, are all platform dependent.
Returns the runtime class representation of the object.
a class object corresponding to the runtime type of the receiver.
The hashCode method for reference types. See hashCode in scala.Any.
the hash code value for this object.
Test whether the dynamic type of the receiver object is T0
.
Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String]
will return false
, while the expression List(1).isInstanceOf[List[String]]
will return true
. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.
true
if the receiver object is an instance of erasure of type T0
; false
otherwise.
Equivalent to !(this eq that)
.
true
if the argument is not a reference to the receiver object; false
otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Wakes up all threads that are waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.
a String representation of the object.
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.13.0/scala/jdk/StreamConverters$.html
This object provides extension methods to create Java Streams that operate on Scala collections (sequentially or in parallel). For more information on Java streams, consult the documentation (https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html).
When writing Java code, use the explicit conversion methods defined in javaapi.StreamConverters instead.
The methods
asJavaSeqStream
andasJavaParStream
convert a collection to a Java Stream:Note: using parallel streams in the Scala REPL causes deadlocks, see https://github.com/scala/bug/issues/9076. As a workaround, use
scala -Yrepl-class-based
.A Java Stream provides operations on a sequence of elements. Streams are created from Spliterators, which are similar to Iterators with the additional capability to partition off some of their elements. This partitioning, if supported by the Spliterator, is used for parallelizing Stream operations.
Scala collections have a method
stepper
that returns a scala.collection.Stepper for the collection, which in turn can be converted to a Spliterator for creating a Java Stream.The
asJavaSeqStream
extension method is available on any Scala collection. TheasJavaParStream
extension method can only be invoked on collections where the return type of thestepper
method is marked with the scala.collection.Stepper.EfficientSplit marker trait. This trait is added to steppers that support partitioning, and therefore efficient parallel processing.The following extension methods are available:
Collection Type
Extension Methods
IterableOnce
asJavaSeqStream
IndexedSeq
, Arrays,BitSet
,Accumulator
,HashMap
,HashSet
,Range
,TreeMap
,TreeSet
,Vector
, StringsasJavaParStream
Map
asJavaSeqKeyStream
,asJavaSeqValueStream
HashMap
,TreeMap
asJavaParKeyStream
,asJavaParValueStream
Stepper
asJavaSeqStream
Stepper with EfficientSplit
asJavaParStream
Strings
asJavaSeqStream
,asJavaParStream
,asJavaSeqCharStream
,asJavaParCharStream
,asJavaSeqCodePointStream
,asJavaParCodePointStream
Java streams
toScala
,asJavaPrimitiveStream
The
asJavaPrimitiveStream
method converts aStream[Int]
to anIntStream
. It is the dual of theboxed
method defined on primitive streams (e.g.,IntStream.boxed
is aStream[Integer]
).The
toScala
extension methods on Java streams collects the result of a stream pipeline into a Scala collection, for examplestream.toScala(List)
,stream.toScala(Vector)
. Note that transformation operations on streams are lazy (also called "intermediate"), terminal operations such asforEach
,count
ortoScala
trigger the evaluation.Collecting a parallel stream to a collection can be performed in parallel. This is beneficial if the target collection supports efficient merging of the segments that are built in parallel. To support this use case, the Scala standard library provides the Accumulator collection. This collection supports efficient parallel construction, and it has specialized subtypes for
Int
,Long
andDouble
so that primitive Java streams can be collected to a Scala collection without boxing the elements.