Object scala.collection.immutable.HashSet
Companion class HashSet
object HashSet extends ImmutableSetFactory[HashSet] with Serializable
Type Members
type Coll = HashSet[_]
The underlying collection type with unknown element type
- Attributes
- protected[this]
- Definition Classes
- GenericCompanion
class HashSet1[A] extends LeafHashSet[A]
class HashTrieSet[A] extends HashSet[A]
A branch node of the HashTrieSet with at least one and up to 32 children.
- A
the type of the elements contained in this hash set. How levels work: When looking up or adding elements, the part of the hashcode that is used to address the children array depends on how deep we are in the tree. This is accomplished by having a level parameter in all internal methods that starts at 0 and increases by 5 (32 = 25) every time we go deeper into the tree. hashcode (binary): 00000000000000000000000000000000 level=0 (depth=0) level=5 (depth=1) level=10 (depth=2) ^^^^ ... Be careful: a non-toplevel HashTrieSet is not a self-contained set, so e.g. calling contains on it will not work! It relies on its depth in the Trie for which part of a hash to use to address the children, but this information (the level) is not stored due to storage efficiency reasons but has to be passed explicitly! How bitmap and elems correspond: A naive implementation of a HashTrieSet would always have an array of size 32 for children and leave the unused children empty (null). But that would be very wasteful regarding memory. Instead, only non-empty children are stored in elems, and the bitmap is used to encode which elem corresponds to which child bucket. The lowest 1 bit corresponds to the first element, the second-lowest to the second, etc. bitmap (binary): 00010000000000000000100000000000 elems: [a,b] children: ---b----------------a-----------
Value Members
final def !=(arg0: Any): Boolean
Test two objects for inequality.
- returns
true
if !(this == that), false otherwise.
- Definition Classes
- AnyRef → Any
final def ##(): Int
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
.
- returns
a hash value consistent with ==
- Definition Classes
- AnyRef → Any
final def ==(arg0: Any): Boolean
The expression x == that
is equivalent to if (x eq null) that eq null else x.equals(that)
.
- returns
true
if the receiver object is equivalent to the argument;false
otherwise.
- Definition Classes
- AnyRef → Any
def apply[A](elems: A*): HashSet[A]
Creates a collection with the specified elements.
- A
the type of the collection's elements
- elems
the elements of the created collection
- returns
a new collection with elements
elems
- Definition Classes
- GenericCompanion
final def asInstanceOf[T0]: T0
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.
- returns
the receiver object.
- Definition Classes
- Any
- Exceptions thrown
ClassCastException
if the receiver object is not an instance of the erasure of typeT0
.
implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, HashSet[A]]
def clone(): AnyRef
Create a copy of the receiver object.
The default implementation of the clone
method is platform dependent.
- returns
a copy of the receiver object.
def empty[A]: HashSet[A]
An empty collection of type Set
[A]
- A
the type of the set's elements
- Definition Classes
- ImmutableSetFactory → GenericCompanion
final def eq(arg0: AnyRef): Boolean
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:
-
It is consistent: for any non-null instances
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
).
- returns
true
if the argument is a reference to the receiver object;false
otherwise.
- Definition Classes
- AnyRef
def equals(arg0: Any): Boolean
The equality method for reference types. Default implementation delegates to eq
.
See also equals
in scala.Any.
- returns
true
if the receiver object is equivalent to the argument;false
otherwise.
- Definition Classes
- AnyRef → Any
def finalize(): Unit
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.
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( classOf[java.lang.Throwable] )
- Note
not specified by SLS as a member of AnyRef
final def getClass(): Class[_]
Returns the runtime class representation of the object.
- returns
a class object corresponding to the runtime type of the receiver.
def hashCode(): Int
The hashCode method for reference types. See hashCode in scala.Any.
- returns
the hash code value for this object.
final def isInstanceOf[T0]: Boolean
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.
- returns
true
if the receiver object is an instance of erasure of typeT0
;false
otherwise.
- Definition Classes
- Any
final def ne(arg0: AnyRef): Boolean
Equivalent to !(this eq that)
.
- returns
true
if the argument is not a reference to the receiver object;false
otherwise.
- Definition Classes
- AnyRef
def newBuilder[A]: Builder[A, HashSet[A]]
The default builder for
objects.Set
- A
the type of the set's elements
- Definition Classes
- ImmutableSetFactory → GenSetFactory → GenericCompanion
final def notify(): Unit
Wakes up a single thread that is waiting on the receiver object's monitor.
- Definition Classes
- AnyRef
- Annotations
- @native()
- Note
not specified by SLS as a member of AnyRef
final def notifyAll(): Unit
Wakes up all threads that are waiting on the receiver object's monitor.
- Definition Classes
- AnyRef
- Annotations
- @native()
- Note
not specified by SLS as a member of AnyRef
def setCanBuildFrom[A]: CanBuildFrom[HashSet[_], A, HashSet[A]]
The standard CanBuildFrom
instance for
objects. Set
- Definition Classes
- GenSetFactory
final def synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
def toString(): String
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.
- returns
a String representation of the object.
- Definition Classes
- AnyRef → Any
final def wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
final def wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
final def wait(arg0: Long): Unit
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.12.9/scala/collection/immutable/HashSet$.html
This object provides a set of operations needed to create
values.immutable.HashSet