class WeakHashMap[K, V] extends JMapWrapper[K, V] with JMapWrapperLike[K, V, WeakHashMap, WeakHashMap[K, V]] with MapFactoryDefaults[K, V, WeakHashMap, Iterable]
A hash map with references to entries which are weakly reachable. Entries are
removed from this map when the key is no longer (strongly) referenced. This class wraps
java.util.WeakHashMap
.
- K
type of keys contained in this map
- V
type of values associated with the keys
- Annotations
- @SerialVersionUID()
- Source
- WeakHashMap.scala
- See also
"Scala's Collection Library overview" section on
Weak Hash Maps
for more information.
- Alphabetic
- By Inheritance
- WeakHashMap
- JMapWrapper
- AbstractJMapWrapper
- Serializable
- JMapWrapperLike
- StrictOptimizedMapOps
- StrictOptimizedIterableOps
- AbstractMap
- Map
- MapOps
- Shrinkable
- Builder
- Growable
- Clearable
- Cloneable
- Cloneable
- Iterable
- AbstractMap
- Map
- Equals
- MapFactoryDefaults
- MapOps
- PartialFunction
- Function1
- AbstractIterable
- Iterable
- IterableFactoryDefaults
- IterableOps
- IterableOnceOps
- IterableOnce
- AnyRef
- Any
- by UnliftOps
- by iterableOnceExtensionMethods
- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
- Hide All
- Show All
- Public
- Protected
Instance Constructors
- new WeakHashMap()
Type Members
- trait GenKeySet extends AnyRef
A generic trait that is reused by keyset implementations
A generic trait that is reused by keyset implementations
- Attributes
- protected
- Definition Classes
- MapOps
- class KeySet extends AbstractSet[K] with GenKeySet with DefaultSerializable
The implementation class of the set returned by
keySet
.The implementation class of the set returned by
keySet
.- Attributes
- protected
- Definition Classes
- MapOps
Value Members
- final def !=(arg0: Any): Boolean
Test two objects for inequality.
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 andnull
.Equivalent to
x.hashCode
except for boxed numeric types andnull
. 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. Fornull
returns a hashcode wherenull.hashCode
throws aNullPointerException
.- returns
a hash value consistent with ==
- Definition Classes
- AnyRef → Any
- def ++[V2 >: V](xs: IterableOnce[(K, V2)]): WeakHashMap[K, V2]
Alias for
concat
Alias for
concat
- Definition Classes
- MapOps
- final def ++[B >: (K, V)](suffix: IterableOnce[B]): Iterable[B]
Alias for
concat
Alias for
concat
- Definition Classes
- IterableOps
- Annotations
- @inline()
- final def ++=(elems: IterableOnce[(K, V)]): WeakHashMap.this.type
Alias for
addAll
- final def +=(elem: (K, V)): WeakHashMap.this.type
Alias for
addOne
- final def --=(xs: IterableOnce[K]): WeakHashMap.this.type
Alias for
subtractAll
Alias for
subtractAll
- Definition Classes
- Shrinkable
- Annotations
- @inline()
- final def -=(elem: K): WeakHashMap.this.type
Alias for
subtractOne
Alias for
subtractOne
- Definition Classes
- Shrinkable
- Annotations
- @inline()
- def ->[B](y: B): (WeakHashMap[K, V], B)
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toArrowAssoc[WeakHashMap[K, V]] performed by method ArrowAssoc in scala.Predef.This conversion will take place only if V is a subclass of Option[Nothing] (V <: Option[Nothing]).
- Definition Classes
- ArrowAssoc
- Annotations
- @inline()
- final def ==(arg0: Any): Boolean
The expression
x == that
is equivalent toif (x eq null) that eq null else x.equals(that)
.The expression
x == that
is equivalent toif (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 addAll(elems: IterableOnce[(K, V)]): WeakHashMap.this.type
Adds all elements produced by an IterableOnce to this weak hash map.
Adds all elements produced by an IterableOnce to this weak hash map.
- elems
the IterableOnce producing the elements to add.
- returns
the weak hash map itself.
- Definition Classes
- Growable
- def addOne(kv: (K, V)): WeakHashMap.this.type
Adds a single element to this weak hash map.
Adds a single element to this weak hash map.
- returns
the weak hash map itself
- Definition Classes
- JMapWrapperLike → Growable
- def addString(sb: StringBuilder, start: String, sep: String, end: String): sb.type
Appends all elements of this weak hash map to a string builder using start, end, and separator strings.
Appends all elements of this weak hash map to a string builder using start, end, and separator strings. The written text begins with the string
start
and ends with the stringend
. Inside, the string representations (w.r.t. the methodtoString
) of all elements of this weak hash map are separated by the stringsep
.Example:
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> a.addString(b , "List(" , ", " , ")") res5: StringBuilder = List(1, 2, 3, 4)
- start
the starting string.
- sep
the separator string.
- end
the ending string.
- returns
the string builder
b
to which elements were appended.
- Definition Classes
- MapOps → IterableOnceOps
- final def addString(b: StringBuilder): b.type
Appends all elements of this weak hash map to a string builder.
Appends all elements of this weak hash map to a string builder. The written text consists of the string representations (w.r.t. the method
toString
) of all elements of this weak hash map without any separator string.Example:
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> val h = a.addString(b) h: StringBuilder = 1234
- b
the string builder to which elements are appended.
- returns
the string builder
b
to which elements were appended.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- final def addString(b: StringBuilder, sep: String): b.type
Appends all elements of this weak hash map to a string builder using a separator string.
Appends all elements of this weak hash map to a string builder using a separator string. The written text consists of the string representations (w.r.t. the method
toString
) of all elements of this weak hash map, separated by the stringsep
.Example:
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> a.addString(b, ", ") res0: StringBuilder = 1, 2, 3, 4
- b
the string builder to which elements are appended.
- sep
the separator string.
- returns
the string builder
b
to which elements were appended.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- def andThen[C](k: PartialFunction[V, C]): PartialFunction[K, C]
Composes this partial function with another partial function that gets applied to results of this partial function.
Composes this partial function with another partial function that gets applied to results of this partial function.
Note that calling isDefinedAt on the resulting partial function may apply the first partial function and execute its side effect. For efficiency, it is recommended to call applyOrElse instead of isDefinedAt or apply.
- C
the result type of the transformation function.
- k
the transformation function
- returns
a partial function with the domain of this partial function narrowed by other partial function, which maps arguments
x
tok(this(x))
.
- Definition Classes
- PartialFunction
- def andThen[C](k: (V) => C): PartialFunction[K, C]
Composes this partial function with a transformation function that gets applied to results of this partial function.
Composes this partial function with a transformation function that gets applied to results of this partial function.
If the runtime type of the function is a
PartialFunction
then the otherandThen
method is used (note its cautions).- C
the result type of the transformation function.
- k
the transformation function
- returns
a partial function with the domain of this partial function, possibly narrowed by the specified function, which maps arguments
x
tok(this(x))
.
- Definition Classes
- PartialFunction → Function1
- def apply(key: K): V
Retrieves the value which is associated with the given key.
Retrieves the value which is associated with the given key. This method invokes the
default
method of the map if there is no mapping from the given key to a value. Unless overridden, thedefault
method throws aNoSuchElementException
.- key
the key
- returns
the value associated with the given key, or the result of the map's
default
method, if none exists.
- def applyOrElse[K1 <: K, V1 >: V](x: K1, default: (K1) => V1): V1
Applies this partial function to the given argument when it is contained in the function domain.
Applies this partial function to the given argument when it is contained in the function domain. Applies fallback function where this partial function is not defined.
Note that expression
pf.applyOrElse(x, default)
is equivalent toif(pf isDefinedAt x) pf(x) else default(x)
except that
applyOrElse
method can be implemented more efficiently. For all partial function literals the compiler generates anapplyOrElse
implementation which avoids double evaluation of pattern matchers and guards. This makesapplyOrElse
the basis for the efficient implementation for many operations and scenarios, such as:- combining partial functions into
orElse
/andThen
chains does not lead to excessiveapply
/isDefinedAt
evaluation lift
andunlift
do not evaluate source functions twice on each invocationrunWith
allows efficient imperative-style combining of partial functions with conditionally applied actions
For non-literal partial function classes with nontrivial
isDefinedAt
method it is recommended to overrideapplyOrElse
with custom implementation that avoids doubleisDefinedAt
evaluation. This may result in better performance and more predictable behavior w.r.t. side effects.- x
the function argument
- default
the fallback function
- returns
the result of this function or fallback function application.
- Definition Classes
- MapOps → PartialFunction
- combining partial functions into
- final def asInstanceOf[T0]: T0
Forces the compiler to treat the receiver object as having type
T0
, even though doing so may violate type safety.Forces the compiler to treat the receiver object as having type
T0
, even though doing so may violate type safety.This method is useful when you believe you have type information the compiler doesn't, and it also isn't possible to check the type at runtime. In such situations, skipping type safety is the only option.
It is platform dependent whether
asInstanceOf
has any effect at runtime. It might do a runtime type test on the erasure ofT0
, insert a conversion (such as boxing/unboxing), fill in a default value, or do nothing at all.In particular,
asInstanceOf
is not a type test. It does **not** mean:this match { case x: T0 => x case _ => throw ClassCastException("...")
Use pattern matching or isInstanceOf for type testing instead.
Situations where
asInstanceOf
is useful:- when flow analysis fails to deduce
T0
automatically - when down-casting a type parameter or an abstract type member (which cannot be checked at runtime due to type erasure) If there is any doubt and you are able to type test instead, you should do so.
Be careful of using
asInstanceOf
whenT0
is a primitive type. WhenT0
is primitive,asInstanceOf
may insert a conversion instead of a type test. If your intent is to convert, use atoT
method (x.toChar
,x.toByte
, etc.).- returns
the receiver object.
- Definition Classes
- Any
- Exceptions thrown
ClassCastException
if the receiver is not an instance of the erasure ofT0
, if that can be checked on this platform
- when flow analysis fails to deduce
- def canEqual(that: Any): Boolean
Checks whether this instance can possibly equal
that
.Checks whether this instance can possibly equal
that
.A method that should be called from every well-designed equals method that is open to be overridden in a subclass. See Programming in Scala, Chapter 28 for discussion and design.
- that
the value being probed for possible equality
- returns
true if this instance can possibly equal
that
, otherwise false
- def className: String
Defines the prefix of this object's
toString
representation.Defines the prefix of this object's
toString
representation.It is recommended to return the name of the concrete collection type, but not implementation subclasses. For example, for
ListMap
this method should return"ListMap"
, not"Map"
(the supertype) or"Node"
(an implementation subclass).The default implementation returns "Iterable". It is overridden for the basic collection kinds "Seq", "IndexedSeq", "LinearSeq", "Buffer", "Set", "Map", "SortedSet", "SortedMap" and "View".
- returns
a string representation which starts the result of
toString
applied to this weak hash map. By default the string prefix is the simple name of the collection class weak hash map.
- Attributes
- protected[this]
- Definition Classes
- Iterable
- def clear(): Unit
Clears the contents of this builder.
- def clone(): WeakHashMap[K, V]
Create a copy of the receiver object.
- final def coll: WeakHashMap.this.type
- returns
This collection as a
C
.
- Attributes
- protected
- Definition Classes
- Iterable → IterableOps
- def collect[K2, V2](pf: PartialFunction[(K, V), (K2, V2)]): WeakHashMap[K2, V2]
Builds a new collection by applying a partial function to all elements of this weak hash map on which the function is defined.
Builds a new collection by applying a partial function to all elements of this weak hash map on which the function is defined.
- K2
the key type of the returned weak hash map.
- V2
the value type of the returned weak hash map.
- pf
the partial function which filters and maps the weak hash map.
- returns
a new weak hash map resulting from applying the given partial function
pf
to each element on which it is defined and collecting the results. The order of the elements is preserved.
- Definition Classes
- StrictOptimizedMapOps → MapOps
- def collect[B](pf: PartialFunction[(K, V), B]): Iterable[B]
Builds a new weak hash map by applying a partial function to all elements of this weak hash map on which the function is defined.
Builds a new weak hash map by applying a partial function to all elements of this weak hash map on which the function is defined.
- B
the element type of the returned weak hash map.
- pf
the partial function which filters and maps the weak hash map.
- returns
a new weak hash map resulting from applying the given partial function
pf
to each element on which it is defined and collecting the results. The order of the elements is preserved.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def collectFirst[B](pf: PartialFunction[(K, V), B]): Option[B]
Finds the first element of the weak hash map for which the given partial function is defined, and applies the partial function to it.
Finds the first element of the weak hash map for which the given partial function is defined, and applies the partial function to it.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- pf
the partial function
- returns
an option value containing pf applied to the first value for which it is defined, or
None
if none exists.
- Definition Classes
- IterableOnceOps
Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)
Example: - def compose[R](k: PartialFunction[R, K]): PartialFunction[R, V]
Composes another partial function
k
with this partial function so that this partial function gets applied to results ofk
.Composes another partial function
k
with this partial function so that this partial function gets applied to results ofk
.Note that calling isDefinedAt on the resulting partial function may apply the first partial function and execute its side effect. For efficiency, it is recommended to call applyOrElse instead of isDefinedAt or apply.
- R
the parameter type of the transformation function.
- k
the transformation function
- returns
a partial function with the domain of other partial function narrowed by this partial function, which maps arguments
x
tothis(k(x))
.
- Definition Classes
- PartialFunction
- def compose[A](g: (A) => K): (A) => V
Composes two instances of
Function1
in a newFunction1
, with this function applied last.Composes two instances of
Function1
in a newFunction1
, with this function applied last.- A
the type to which function
g
can be applied- g
a function A => T1
- returns
a new function
f
such thatf(x) == apply(g(x))
- Definition Classes
- Function1
- Annotations
- @unspecialized()
- def concat[V2 >: V](suffix: IterableOnce[(K, V2)]): WeakHashMap[K, V2]
Returns a new weak hash map containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new weak hash map containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the weak hash map is the most specific superclass encompassing the element types of the two operands.
- suffix
the iterable to append.
- returns
a new weak hash map which contains all elements of this weak hash map followed by all elements of
suffix
.
- Definition Classes
- StrictOptimizedMapOps → MapOps
- def concat[B >: (K, V)](suffix: IterableOnce[B]): Iterable[B]
Returns a new weak hash map containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new weak hash map containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the weak hash map is the most specific superclass encompassing the element types of the two operands.
- B
the element type of the returned collection.
- suffix
the iterable to append.
- returns
a new weak hash map which contains all elements of this weak hash map followed by all elements of
suffix
.
- Definition Classes
- IterableOps
- def contains(key: K): Boolean
Tests whether this map contains a binding for a key.
Tests whether this map contains a binding for a key.
- key
the key
- returns
true
if there is a binding forkey
in this map,false
otherwise.
- Definition Classes
- MapOps
- def copyToArray[B >: (K, V)](xs: Array[B], start: Int, len: Int): Int
Copy elements to an array, returning the number of elements written.
Copy elements to an array, returning the number of elements written.
Fills the given array
xs
starting at indexstart
with at mostlen
elements of this weak hash map.Copying will stop once either all the elements of this weak hash map have been copied, or the end of the array is reached, or
len
elements have been copied.- B
the type of the elements of the array.
- xs
the array to fill.
- start
the starting index of xs.
- len
the maximal number of elements to copy.
- returns
the number of elements written to the array
- Definition Classes
- IterableOnceOps
- Note
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- def copyToArray[B >: (K, V)](xs: Array[B], start: Int): Int
Copies elements to an array, returning the number of elements written.
Copies elements to an array, returning the number of elements written.
Fills the given array
xs
starting at indexstart
with values of this weak hash map.Copying will stop once either all the elements of this weak hash map have been copied, or the end of the array is reached.
- B
the type of the elements of the array.
- xs
the array to fill.
- start
the starting index of xs.
- returns
the number of elements written to the array
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecatedOverriding()
- Note
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- def copyToArray[B >: (K, V)](xs: Array[B]): Int
Copies elements to an array, returning the number of elements written.
Copies elements to an array, returning the number of elements written.
Fills the given array
xs
starting at indexstart
with values of this weak hash map.Copying will stop once either all the elements of this weak hash map have been copied, or the end of the array is reached.
- B
the type of the elements of the array.
- xs
the array to fill.
- returns
the number of elements written to the array
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecatedOverriding()
- Note
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- def corresponds[B](that: IterableOnce[B])(p: ((K, V), B) => Boolean): Boolean
Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.
Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.
- B
the type of the elements of
that
- that
the other collection
- p
the test predicate, which relates elements from both collections
- returns
true
if both collections have the same length andp(x, y)
istrue
for all corresponding elementsx
of this iterator andy
ofthat
, otherwisefalse
- Definition Classes
- IterableOnceOps
- def count(p: ((K, V)) => Boolean): Int
Counts the number of elements in the weak hash map which satisfy a predicate.
Counts the number of elements in the weak hash map which satisfy a predicate.
- p
the predicate used to test elements.
- returns
the number of elements satisfying the predicate
p
.
- Definition Classes
- IterableOnceOps
- def default(key: K): V
Defines the default value computation for the map, returned when a key is not found.
Defines the default value computation for the map, returned when a key is not found.
The method implemented here throws an exception, but it may be overridden by subclasses.
- key
the given key value for which a binding is missing.
- Definition Classes
- MapOps
- Annotations
- @throws(cause = scala.this.throws.<init>$default$1[NoSuchElementException])
- Exceptions thrown
NoSuchElementException
if no default value is defined
- def drop(n: Int): WeakHashMap[K, V]
Selects all elements except the first
n
ones.Selects all elements except the first
n
ones.Note: might return different results for different runs, unless the underlying collection type is ordered.
- n
the number of elements to drop from this weak hash map.
- returns
a weak hash map consisting of all elements of this weak hash map except the first
n
ones, or else the empty weak hash map, if this weak hash map has less thann
elements. Ifn
is negative, don't drop any elements.
- Definition Classes
- IterableOps → IterableOnceOps
- def dropRight(n: Int): WeakHashMap[K, V]
The rest of the collection without its
n
last elements.The rest of the collection without its
n
last elements. For linear, immutable collections this should avoid making a copy.Note: Even when applied to a view or a lazy collection it will always force the elements.
- n
the number of elements to drop from this weak hash map.
- returns
a weak hash map consisting of all elements of this weak hash map except the last
n
ones, or else the empty weak hash map, if this weak hash map has less thann
elements. Ifn
is negative, don't drop any elements.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def dropWhile(p: ((K, V)) => Boolean): WeakHashMap[K, V]
Selects all elements except the longest prefix that satisfies a predicate.
Selects all elements except the longest prefix that satisfies a predicate.
The matching prefix starts with the first element of this weak hash map, and the element following the prefix is the first element that does not satisfy the predicate. The matching prefix may be empty, so that this method returns the entire weak hash map.
Example:
scala> List(1, 2, 3, 100, 4).dropWhile(n => n < 10) val res0: List[Int] = List(100, 4) scala> List(1, 2, 3, 100, 4).dropWhile(n => n == 0) val res1: List[Int] = List(1, 2, 3, 100, 4)
Use span to obtain both the prefix and suffix. Use filterNot to drop all elements that satisfy the predicate.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- p
The predicate used to test elements.
- returns
the longest suffix of this weak hash map whose first element does not satisfy the predicate
p
.
- Definition Classes
- IterableOps → IterableOnceOps
- def elementWise: ElementWiseExtractor[K, V]
Returns an extractor object with a
unapplySeq
method, which extracts each element of a sequence data.Returns an extractor object with a
unapplySeq
method, which extracts each element of a sequence data.- Definition Classes
- PartialFunction
val firstChar: String => Option[Char] = _.headOption Seq("foo", "bar", "baz") match { case firstChar.unlift.elementWise(c0, c1, c2) => println(s"$c0, $c1, $c2") // Output: f, b, b }
Example: - def empty: WeakHashMap[K, V]
The empty iterable of the same type as this iterable.
The empty iterable of the same type as this iterable.
- returns
an empty iterable of type
C
.
- Definition Classes
- WeakHashMap → JMapWrapper → MapFactoryDefaults → IterableFactoryDefaults → IterableOps
- def ensuring(cond: (WeakHashMap[K, V]) => Boolean, msg: => Any): WeakHashMap[K, V]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toEnsuring[WeakHashMap[K, V]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: (WeakHashMap[K, V]) => Boolean): WeakHashMap[K, V]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toEnsuring[WeakHashMap[K, V]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: Boolean, msg: => Any): WeakHashMap[K, V]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toEnsuring[WeakHashMap[K, V]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: Boolean): WeakHashMap[K, V]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toEnsuring[WeakHashMap[K, V]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- final def eq(arg0: AnyRef): Boolean
Tests whether the argument (
that
) is a reference to the receiver object (this
).Tests whether the argument (
that
) is a reference to the receiver object (this
).The
eq
method implements an equivalence relation on non-null instances ofAnyRef
, and has three additional properties:- It is consistent: for any non-null instances
x
andy
of typeAnyRef
, multiple invocations ofx.eq(y)
consistently returnstrue
or consistently returnsfalse
. - For any non-null instance
x
of typeAnyRef
,x.eq(null)
andnull.eq(x)
returnsfalse
. null.eq(null)
returnstrue
.
When overriding the
equals
orhashCode
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
- It is consistent: for any non-null instances
- def equals(o: Any): Boolean
Equality of maps is implemented using the lookup method get.
Equality of maps is implemented using the lookup method get. This method returns
true
if- the argument
o
is aMap
, - the two maps have the same size, and
- for every
(key, value)
pair in this map,other.get(key) == Some(value)
.
The implementation of
equals
checks the canEqual method, so subclasses ofMap
can narrow down the equality to specific map types. TheMap
implementations in the standard library can all be compared, theircanEqual
methods returntrue
.Note: The
equals
method only respects the equality laws (symmetry, transitivity) if the two maps use the same key equivalence function in their lookup operation. For example, the key equivalence operation in a scala.collection.immutable.TreeMap is defined by its ordering. Comparing aTreeMap
with aHashMap
leads to unexpected results ifordering.equiv(k1, k2)
(used for lookup inTreeMap
) is different fromk1 == k2
(used for lookup inHashMap
).scala> import scala.collection.immutable._ scala> val ord: Ordering[String] = _ compareToIgnoreCase _ scala> TreeMap("A" -> 1)(ord) == HashMap("a" -> 1) val res0: Boolean = false scala> HashMap("a" -> 1) == TreeMap("A" -> 1)(ord) val res1: Boolean = true
- o
The map to which this map is compared
- returns
true
if the two maps are equal according to the description
- the argument
- def exists(p: ((K, V)) => Boolean): Boolean
Tests whether a predicate holds for at least one element of this weak hash map.
Tests whether a predicate holds for at least one element of this weak hash map.
- p
the predicate used to test elements.
- returns
true
if the given predicatep
is satisfied by at least one element of this weak hash map, otherwisefalse
- Definition Classes
- IterableOnceOps
- def filter(pred: ((K, V)) => Boolean): WeakHashMap[K, V]
Selects all elements of this weak hash map which satisfy a predicate.
Selects all elements of this weak hash map which satisfy a predicate.
- returns
a new weak hash map consisting of all elements of this weak hash map that satisfy the given predicate
p
. The order of the elements is preserved.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def filterImpl(pred: ((K, V)) => Boolean, isFlipped: Boolean): WeakHashMap[K, V]
- Attributes
- protected[collection]
- Definition Classes
- StrictOptimizedIterableOps
- def filterInPlace(p: (K, V) => Boolean): WeakHashMap.this.type
Retains only those mappings for which the predicate
p
returnstrue
.Retains only those mappings for which the predicate
p
returnstrue
.- p
The test predicate
- Definition Classes
- MapOps
- def filterNot(pred: ((K, V)) => Boolean): WeakHashMap[K, V]
Selects all elements of this weak hash map which do not satisfy a predicate.
Selects all elements of this weak hash map which do not satisfy a predicate.
- pred
the predicate used to test elements.
- returns
a new weak hash map consisting of all elements of this weak hash map that do not satisfy the given predicate
pred
. Their order may not be preserved.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def finalize(): Unit
Called by the garbage collector on the receiver object when there are no more references to the object.
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 betweenfinalize
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
- def find(p: ((K, V)) => Boolean): Option[(K, V)]
Finds the first element of the weak hash map satisfying a predicate, if any.
Finds the first element of the weak hash map satisfying a predicate, if any.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- p
the predicate used to test elements.
- returns
an option value containing the first element in the weak hash map that satisfies
p
, orNone
if none exists.
- Definition Classes
- IterableOnceOps
- def flatMap[K2, V2](f: ((K, V)) => IterableOnce[(K2, V2)]): WeakHashMap[K2, V2]
Builds a new map by applying a function to all elements of this weak hash map and using the elements of the resulting collections.
Builds a new map by applying a function to all elements of this weak hash map and using the elements of the resulting collections.
- f
the function to apply to each element.
- returns
a new weak hash map resulting from applying the given collection-valued function
f
to each element of this weak hash map and concatenating the results.
- Definition Classes
- StrictOptimizedMapOps → MapOps
- def flatMap[B](f: ((K, V)) => IterableOnce[B]): Iterable[B]
Builds a new weak hash map by applying a function to all elements of this weak hash map and using the elements of the resulting collections.
Builds a new weak hash map by applying a function to all elements of this weak hash map and using the elements of the resulting collections.
For example:
def getWords(lines: Seq[String]): Seq[String] = lines flatMap (line => line split "\\W+")
The type of the resulting collection is guided by the static type of weak hash map. This might cause unexpected results sometimes. For example:
// lettersOf will return a Seq[Char] of likely repeated letters, instead of a Set def lettersOf(words: Seq[String]) = words flatMap (word => word.toSet) // lettersOf will return a Set[Char], not a Seq def lettersOf(words: Seq[String]) = words.toSet flatMap ((word: String) => word.toSeq) // xs will be an Iterable[Int] val xs = Map("a" -> List(11,111), "b" -> List(22,222)).flatMap(_._2) // ys will be a Map[Int, Int] val ys = Map("a" -> List(1 -> 11,1 -> 111), "b" -> List(2 -> 22,2 -> 222)).flatMap(_._2)
- B
the element type of the returned collection.
- f
the function to apply to each element.
- returns
a new weak hash map resulting from applying the given collection-valued function
f
to each element of this weak hash map and concatenating the results.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def flatten[B](implicit toIterableOnce: ((K, V)) => IterableOnce[B]): Iterable[B]
Converts this weak hash map of iterable collections into a weak hash map formed by the elements of these iterable collections.
Converts this weak hash map of iterable collections into a weak hash map formed by the elements of these iterable collections.
The resulting collection's type will be guided by the type of weak hash map. For example:
val xs = List( Set(1, 2, 3), Set(1, 2, 3) ).flatten // xs == List(1, 2, 3, 1, 2, 3) val ys = Set( List(1, 2, 3), List(3, 2, 1) ).flatten // ys == Set(1, 2, 3)
- B
the type of the elements of each iterable collection.
- returns
a new weak hash map resulting from concatenating all element weak hash maps.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def fold[A1 >: (K, V)](z: A1)(op: (A1, A1) => A1): A1
Applies the given binary operator
op
to the given initial valuez
and all elements of this weak hash map.Applies the given binary operator
op
to the given initial valuez
and all elements of this weak hash map.For each application of the operator, each operand is either an element of this weak hash map, the initial value, or another such application of the operator.
The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation. The initial value may be used an arbitrary number of times, but at least once.
If this collection is ordered, then for any application of the operator, the element(s) appearing in the left operand will precede those in the right.
Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative. In either case, it is also necessary that the initial value be a neutral value for the operator, e.g.
Nil
forList
concatenation or1
for multiplication.The default implementation in
IterableOnce
is equivalent tofoldLeft
but may be overridden for more efficient traversal orders.- A1
The type parameter for the binary operator, a supertype of
A
.- z
An initial value; may be used an arbitrary number of times in the computation of the result; must be a neutral value for
op
for the result to always be the same across runs.- op
A binary operator; must be associative for the result to always be the same across runs.
- returns
The result of applying
op
between all the elements andz
, orz
if this weak hash map is empty.
- Definition Classes
- IterableOnceOps
- def foldLeft[B](z: B)(op: (B, (K, V)) => B): B
Applies the given binary operator
op
to the given initial valuez
and all elements of this weak hash map, going left to right.Applies the given binary operator
op
to the given initial valuez
and all elements of this weak hash map, going left to right. Returns the initial value if this weak hash map is empty."Going left to right" only makes sense if this collection is ordered: then if
x1
,x2
, ...,xn
are the elements of this weak hash map, the result isop( op( ... op( op(z, x1), x2) ... ), xn)
.If this collection is not ordered, then for each application of the operator, each right operand is an element. In addition, the leftmost operand is the initial value, and each other left operand is itself an application of the operator. The elements of this weak hash map and the initial value all appear exactly once in the computation.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- B
The result type of the binary operator.
- z
An initial value.
- op
A binary operator.
- returns
The result of applying
op
toz
and all elements of this weak hash map, going left to right. Returnsz
if this weak hash map is empty.
- Definition Classes
- IterableOnceOps
- def foldRight[B](z: B)(op: ((K, V), B) => B): B
Applies the given binary operator
op
to all elements of this weak hash map and the given initial valuez
, going right to left.Applies the given binary operator
op
to all elements of this weak hash map and the given initial valuez
, going right to left. Returns the initial value if this weak hash map is empty."Going right to left" only makes sense if this collection is ordered: then if
x1
,x2
, ...,xn
are the elements of this weak hash map, the result isop(x1, op(x2, op( ... op(xn, z) ... )))
.If this collection is not ordered, then for each application of the operator, each left operand is an element. In addition, the rightmost operand is the initial value, and each other right operand is itself an application of the operator. The elements of this weak hash map and the initial value all appear exactly once in the computation.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- B
The result type of the binary operator.
- z
An initial value.
- op
A binary operator.
- returns
The result of applying
op
to all elements of this weak hash map andz
, going right to left. Returnsz
if this weak hash map is empty.
- Definition Classes
- IterableOnceOps
- def forall(p: ((K, V)) => Boolean): Boolean
Tests whether a predicate holds for all elements of this weak hash map.
Tests whether a predicate holds for all elements of this weak hash map.
- p
the predicate used to test elements.
- returns
true
if this weak hash map is empty or the given predicatep
holds for all elements of this weak hash map, otherwisefalse
.
- Definition Classes
- IterableOnceOps
- def foreach[U](f: ((K, V)) => U): Unit
Applies
f
to each element for its side effects.Applies
f
to each element for its side effects. Note:U
parameter needed to help scalac's type inference.- Definition Classes
- IterableOnceOps
- def foreachEntry[U](f: (K, V) => U): Unit
Apply
f
to each key/value pair for its side effects Note: [U] parameter needed to help scalac's type inference.Apply
f
to each key/value pair for its side effects Note: [U] parameter needed to help scalac's type inference.- Definition Classes
- JMapWrapperLike → MapOps
- def fromSpecific(coll: IterableOnce[(K, V)]): WeakHashMap[K, V]
Defines how to turn a given
Iterable[A]
into a collection of typeC
.Defines how to turn a given
Iterable[A]
into a collection of typeC
.This process can be done in a strict way or a non-strict way (ie. without evaluating the elements of the resulting collections). In other words, this methods defines the evaluation model of the collection.
- Attributes
- protected
- Definition Classes
- MapFactoryDefaults → IterableOps
- Note
When implementing a custom collection type and refining
,C
to the new type, this method needs to be overridden (the compiler will issue an error otherwise). In the common case whereC =:= CC[A]
, this can be done by mixing in the scala.collection.IterableFactoryDefaults trait, which implements the method using iterableFactory.As witnessed by the
@uncheckedVariance
annotation, using this method might be unsound. However, as long as it is called with anIterable[A]
obtained fromthis
collection (as it is the case in the implementations of operations where we use aView[A]
), it is safe.
- def get(k: K): Option[V]
Optionally returns the value associated with a key.
Optionally returns the value associated with a key.
- returns
an option value containing the value associated with
key
in this map, orNone
if none exists.
- Definition Classes
- JMapWrapperLike → MapOps
- final def getClass(): Class[_ <: AnyRef]
Returns the runtime class representation of the object.
- def getOrElse[V1 >: V](key: K, default: => V1): V1
Returns the value associated with a key, or a default value if the key is not contained in the map.
Returns the value associated with a key, or a default value if the key is not contained in the map.
- V1
the result type of the default computation.
- key
the key.
- default
a computation that yields a default value in case no binding for
key
is found in the map.- returns
the value associated with
key
if it exists, otherwise the result of thedefault
computation.
- Definition Classes
- MapOps
- def getOrElseUpdate(key: K, op: => V): V
If given key is already in this map, returns associated value.
If given key is already in this map, returns associated value.
Otherwise, computes value from given expression
defaultValue
, stores with key in map and returns that value.Concurrent map implementations may evaluate the expression
defaultValue
multiple times, or may evaluatedefaultValue
without inserting the result.- key
the key to test
- returns
the value associated with key (either previously or as a result of executing the method).
- Definition Classes
- JMapWrapperLike → MapOps
- def groupBy[K](f: ((K, V)) => K): immutable.Map[K, WeakHashMap[K, V]]
Partitions this weak hash map into a map of weak hash maps according to some discriminator function.
Partitions this weak hash map into a map of weak hash maps according to some discriminator function.
Note: Even when applied to a view or a lazy collection it will always force the elements.
- K
the type of keys returned by the discriminator function.
- f
the discriminator function.
- returns
A map from keys to weak hash maps such that the following invariant holds:
(xs groupBy f)(k) = xs filter (x => f(x) == k)
That is, every key
k
is bound to a weak hash map of those elementsx
for whichf(x)
equalsk
.
- Definition Classes
- IterableOps
- def groupMap[K, B](key: ((K, V)) => K)(f: ((K, V)) => B): immutable.Map[K, Iterable[B]]
Partitions this weak hash map into a map of weak hash maps according to a discriminator function
key
.Partitions this weak hash map into a map of weak hash maps according to a discriminator function
key
. Each element in a group is transformed into a value of typeB
using thevalue
function.It is equivalent to
groupBy(key).mapValues(_.map(f))
, but more efficient.case class User(name: String, age: Int) def namesByAge(users: Seq[User]): Map[Int, Seq[String]] = users.groupMap(_.age)(_.name)
Note: Even when applied to a view or a lazy collection it will always force the elements.
- K
the type of keys returned by the discriminator function
- B
the type of values returned by the transformation function
- key
the discriminator function
- f
the element transformation function
- Definition Classes
- IterableOps
- def groupMapReduce[K, B](key: ((K, V)) => K)(f: ((K, V)) => B)(reduce: (B, B) => B): immutable.Map[K, B]
Partitions this weak hash map into a map according to a discriminator function
key
.Partitions this weak hash map into a map according to a discriminator function
key
. All the values that have the same discriminator are then transformed by thef
function and then reduced into a single value with thereduce
function.It is equivalent to
groupBy(key).mapValues(_.map(f).reduce(reduce))
, but more efficient.def occurrences[A](as: Seq[A]): Map[A, Int] = as.groupMapReduce(identity)(_ => 1)(_ + _)
Note: Even when applied to a view or a lazy collection it will always force the elements.
- Definition Classes
- IterableOps
- def grouped(size: Int): Iterator[WeakHashMap[K, V]]
Partitions elements in fixed size weak hash maps.
Partitions elements in fixed size weak hash maps.
- size
the number of elements per group
- returns
An iterator producing weak hash maps of size
size
, except the last will be less than sizesize
if the elements don't divide evenly.
- Definition Classes
- IterableOps
- See also
scala.collection.Iterator, method
grouped
- def hashCode(): Int
The hashCode method for reference types.
- def head: (K, V)
Selects the first element of this weak hash map.
Selects the first element of this weak hash map.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- returns
the first element of this weak hash map.
- Definition Classes
- IterableOps
- Exceptions thrown
NoSuchElementException
if the weak hash map is empty.
- def headOption: Option[(K, V)]
Optionally selects the first element.
Optionally selects the first element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- returns
the first element of this weak hash map if it is nonempty,
None
if it is empty.
- Definition Classes
- IterableOps
- def init: WeakHashMap[K, V]
The initial part of the collection without its last element.
The initial part of the collection without its last element.
Note: Even when applied to a view or a lazy collection it will always force the elements.
- Definition Classes
- IterableOps
- def inits: Iterator[WeakHashMap[K, V]]
Iterates over the inits of this weak hash map.
Iterates over the inits of this weak hash map. The first value will be this weak hash map and the final one will be an empty weak hash map, with the intervening values the results of successive applications of
init
.Note: Even when applied to a view or a lazy collection it will always force the elements.
- returns
an iterator over all the inits of this weak hash map
- Definition Classes
- IterableOps
List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)
Example: - def isDefinedAt(key: K): Boolean
Tests whether this map contains a binding for a key.
Tests whether this map contains a binding for a key. This method, which implements an abstract method of trait
PartialFunction
, is equivalent tocontains
.- key
the key
- returns
true
if there is a binding forkey
in this map,false
otherwise.
- Definition Classes
- MapOps → PartialFunction
- def isEmpty: Boolean
Tests whether the weak hash map is empty.
Tests whether the weak hash map is empty.
Note: The default implementation creates and discards an iterator.
Note: Implementations in subclasses that are not repeatedly iterable must take care not to consume any elements when
isEmpty
is called.- returns
true
if the weak hash map contains no elements,false
otherwise.
- Definition Classes
- JMapWrapper → IterableOnceOps
- final def isInstanceOf[T0]: Boolean
Test whether the dynamic type of the receiver object has the same erasure as
T0
.Test whether the dynamic type of the receiver object has the same erasure as
T0
.Depending on what
T0
is, the test is done in one of the below ways:T0
is a non-parameterized class type, e.g.BigDecimal
: this method returnstrue
if the value of the receiver object is aBigDecimal
or a subtype ofBigDecimal
.T0
is a parameterized class type, e.g.List[Int]
: this method returnstrue
if the value of the receiver object is someList[X]
for anyX
. For example,List(1, 2, 3).isInstanceOf[List[String]]
will return true.T0
is some singleton typex.type
or literalx
: this method returnsthis.eq(x)
. For example,x.isInstanceOf[1]
is equivalent tox.eq(1)
T0
is an intersectionX with Y
orX & Y: this method is equivalent to
x.isInstanceOf[X] && x.isInstanceOf[Y]T0
is a unionX | Y
: this method is equivalent tox.isInstanceOf[X] || x.isInstanceOf[Y]
T0
is a type parameter or an abstract type member: this method is equivalent toisInstanceOf[U]
whereU
isT0
's upper bound,Any
ifT0
is unbounded. For example,x.isInstanceOf[A]
whereA
is an unbounded type parameter will return true for any value ofx
.
This is exactly equivalent to the type pattern
_: T0
- returns
true
if the receiver object is an instance of erasure of typeT0
;false
otherwise.
- Definition Classes
- Any
- Note
due to the unexpectedness of
List(1, 2, 3).isInstanceOf[List[String]]
returning true andx.isInstanceOf[A]
whereA
is a type parameter or abstract member returning true, these forms issue a warning.
- def isTraversableAgain: Boolean
Tests whether this weak hash map can be repeatedly traversed.
Tests whether this weak hash map can be repeatedly traversed. Always true for Iterables and false for Iterators unless overridden.
- returns
true
if it is repeatedly traversable,false
otherwise.
- Definition Classes
- IterableOps → IterableOnceOps
- def iterableFactory: IterableFactory[Iterable]
The companion object of this weak hash map, providing various factory methods.
The companion object of this weak hash map, providing various factory methods.
- Definition Classes
- Iterable → Iterable → IterableOps
- Note
When implementing a custom collection type and refining
CC
to the new type, this method needs to be overridden to return a factory for the new type (the compiler will issue an error otherwise).
- def iterator: Iterator[(K, V)]
An scala.collection.Iterator over the elements of this weak hash map.
An scala.collection.Iterator over the elements of this weak hash map.
If an
IterableOnce
object is in fact an scala.collection.Iterator, this method always returns itself, in its current state, but if it is an scala.collection.Iterable, this method always returns a new scala.collection.Iterator.- Definition Classes
- JMapWrapperLike → IterableOnce
- def keySet: collection.Set[K]
A set representing the keys contained by this map.
A set representing the keys contained by this map.
For efficiency the resulting set may be a view (maintaining a reference to the map and reflecting modifications to the map), but it may also be a strict collection without reference to the map.
- To ensure an independent strict collection, use
m.keysIterator.toSet
- To obtain a view on the keys, use
scala.collection.View.fromIteratorProvider(m.keysIterator)
- returns
a set representing the keys contained by this map
- Definition Classes
- MapOps
- To ensure an independent strict collection, use
- def keyStepper[S <: Stepper[_]](implicit shape: StepperShape[K, S]): S
Returns a Stepper for the keys of this map.
- def keys: collection.Iterable[K]
An Iterable collection of the keys contained by this map.
An Iterable collection of the keys contained by this map.
For efficiency the resulting collection may be a view (maintaining a reference to the map and reflecting modifications to the map), but it may also be a strict collection without reference to the map.
- To ensure an independent strict collection, use
m.keysIterator.toSet
- To obtain a view on the keys, use
scala.collection.View.fromIteratorProvider(m.keysIterator)
- returns
an Iterable collection of the keys contained by this map
- Definition Classes
- MapOps
- Annotations
- @deprecatedOverriding()
- To ensure an independent strict collection, use
- def keysIterator: Iterator[K]
An Iterator of the keys contained by this map.
- 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.
- returns
The number of elements. The default implementation always returns -1.
- Definition Classes
- JMapWrapper → MapOps → Growable → IterableOnce
- def last: (K, V)
Selects the last element.
Selects the last element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- returns
The last element of this weak hash map.
- Definition Classes
- IterableOps
- Exceptions thrown
NoSuchElementException
If the weak hash map is empty.
- def lastOption: Option[(K, V)]
Optionally selects the last element.
Optionally selects the last element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- returns
the last element of this weak hash map$ if it is nonempty,
None
if it is empty.
- Definition Classes
- IterableOps
- def lazyZip[B](that: collection.Iterable[B]): LazyZip2[(K, V), B, WeakHashMap.this.type]
Analogous to
zip
except that the elements in each collection are not consumed until a strict operation is invoked on the returnedLazyZip2
decorator.Analogous to
zip
except that the elements in each collection are not consumed until a strict operation is invoked on the returnedLazyZip2
decorator.Calls to
lazyZip
can be chained to support higher arities (up to 4) without incurring the expense of constructing and deconstructing intermediary tuples.val xs = List(1, 2, 3) val res = (xs lazyZip xs lazyZip xs lazyZip xs).map((a, b, c, d) => a + b + c + d) // res == List(4, 8, 12)
- B
the type of the second element in each eventual pair
- that
the iterable providing the second element of each eventual pair
- returns
a decorator
LazyZip2
that allows strict operations to be performed on the lazily evaluated pairs or chained calls tolazyZip
. Implicit conversion toIterable[(A, B)]
is also supported.
- Definition Classes
- Iterable
- def lift: (K) => Option[V]
Turns this partial function into a plain function returning an
Option
result.Turns this partial function into a plain function returning an
Option
result.- returns
a function that takes an argument
x
toSome(this(x))
ifthis
is defined forx
, and toNone
otherwise.
- Definition Classes
- PartialFunction
- See also
Function.unlift
- def map[K2, V2](f: ((K, V)) => (K2, V2)): WeakHashMap[K2, V2]
Builds a new map by applying a function to all elements of this weak hash map.
Builds a new map by applying a function to all elements of this weak hash map.
- f
the function to apply to each element.
- returns
a new weak hash map resulting from applying the given function
f
to each element of this weak hash map and collecting the results.
- Definition Classes
- StrictOptimizedMapOps → MapOps
- def map[B](f: ((K, V)) => B): Iterable[B]
Builds a new weak hash map by applying a function to all elements of this weak hash map.
Builds a new weak hash map by applying a function to all elements of this weak hash map.
- B
the element type of the returned weak hash map.
- f
the function to apply to each element.
- returns
a new weak hash map resulting from applying the given function
f
to each element of this weak hash map and collecting the results.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def mapFactory: MapFactory[WeakHashMap]
The companion object of this map, providing various factory methods.
The companion object of this map, providing various factory methods.
- Definition Classes
- WeakHashMap → Map → Map → MapOps
- Note
When implementing a custom collection type and refining
CC
to the new type, this method needs to be overridden to return a factory for the new type (the compiler will issue an error otherwise).
- final def mapFromIterable[K2, V2](it: collection.Iterable[(K2, V2)]): WeakHashMap[K2, V2]
Similar to
fromIterable
, but returns a Map collection type. - def mapResult[NewTo](f: (WeakHashMap[K, V]) => NewTo): Builder[(K, V), 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
.- Definition Classes
- Builder
- def mapValuesInPlace(f: (K, V) => V): WeakHashMap.this.type
Applies a transformation function to all values contained in this map.
Applies a transformation function to all values contained in this map. The transformation function produces new values from existing keys associated values.
- f
the transformation to apply
- returns
the map itself.
- Definition Classes
- MapOps
- def max[B >: (K, V)](implicit ord: math.Ordering[B]): (K, V)
Finds the largest element.
Finds the largest element.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
the largest element of this weak hash map with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this weak hash map is empty.
- def maxBy[B](f: ((K, V)) => B)(implicit ord: math.Ordering[B]): (K, V)
Finds the first element which yields the largest value measured by function
f
.Finds the first element which yields the largest value measured by function
f
.- B
The result type of the function
f
.- f
The measuring function.
- returns
the first element of this weak hash map with the largest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this weak hash map is empty.
- def maxByOption[B](f: ((K, V)) => B)(implicit ord: math.Ordering[B]): Option[(K, V)]
Finds the first element which yields the largest value measured by function
f
.Finds the first element which yields the largest value measured by function
f
.- B
The result type of the function
f
.- f
The measuring function.
- returns
an option value containing the first element of this weak hash map with the largest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- def maxOption[B >: (K, V)](implicit ord: math.Ordering[B]): Option[(K, V)]
Finds the largest element.
Finds the largest element.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
an option value containing the largest element of this weak hash map with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- def min[B >: (K, V)](implicit ord: math.Ordering[B]): (K, V)
Finds the smallest element.
Finds the smallest element.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
the smallest element of this weak hash map with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this weak hash map is empty.
- def minBy[B](f: ((K, V)) => B)(implicit ord: math.Ordering[B]): (K, V)
Finds the first element which yields the smallest value measured by function
f
.Finds the first element which yields the smallest value measured by function
f
.- B
The result type of the function
f
.- f
The measuring function.
- returns
the first element of this weak hash map with the smallest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this weak hash map is empty.
- def minByOption[B](f: ((K, V)) => B)(implicit ord: math.Ordering[B]): Option[(K, V)]
Finds the first element which yields the smallest value measured by function
f
.Finds the first element which yields the smallest value measured by function
f
.- B
The result type of the function
f
.- f
The measuring function.
- returns
an option value containing the first element of this weak hash map with the smallest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- def minOption[B >: (K, V)](implicit ord: math.Ordering[B]): Option[(K, V)]
Finds the smallest element.
Finds the smallest element.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
an option value containing the smallest element of this weak hash map with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- final def mkString: String
Displays all elements of this weak hash map in a string.
Displays all elements of this weak hash map in a string.
Delegates to addString, which can be overridden.
- returns
a string representation of this weak hash map. In the resulting string the string representations (w.r.t. the method
toString
) of all elements of this weak hash map follow each other without any separator string.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- final def mkString(sep: String): String
Displays all elements of this weak hash map in a string using a separator string.
Displays all elements of this weak hash map in a string using a separator string.
Delegates to addString, which can be overridden.
- sep
the separator string.
- returns
a string representation of this weak hash map. In the resulting string the string representations (w.r.t. the method
toString
) of all elements of this weak hash map are separated by the stringsep
.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
List(1, 2, 3).mkString("|") = "1|2|3"
Example: - final def mkString(start: String, sep: String, end: String): String
Displays all elements of this weak hash map in a string using start, end, and separator strings.
Displays all elements of this weak hash map in a string using start, end, and separator strings.
Delegates to addString, which can be overridden.
- start
the starting string.
- sep
the separator string.
- end
the ending string.
- returns
a string representation of this weak hash map. The resulting string begins with the string
start
and ends with the stringend
. Inside, the string representations (w.r.t. the methodtoString
) of all elements of this weak hash map are separated by the stringsep
.
- Definition Classes
- IterableOnceOps
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
Example: - final def ne(arg0: AnyRef): Boolean
Equivalent to
!(this eq that)
.Equivalent to
!(this eq that)
.- returns
true
if the argument is not a reference to the receiver object;false
otherwise.
- Definition Classes
- AnyRef
- def newSpecificBuilder: Builder[(K, V), WeakHashMap[K, V]]
- returns
a strict builder for the same collection type. Note that in the case of lazy collections (e.g. scala.collection.View or scala.collection.immutable.LazyList), it is possible to implement this method but the resulting
Builder
will break laziness. As a consequence, operations should preferably be implemented withfromSpecific
instead of this method.
- Attributes
- protected
- Definition Classes
- MapFactoryDefaults → IterableOps
- Note
When implementing a custom collection type and refining
,C
to the new type, this method needs to be overridden (the compiler will issue an error otherwise). In the common case whereC =:= CC[A]
, this can be done by mixing in the scala.collection.IterableFactoryDefaults trait, which implements the method using iterableFactory.As witnessed by the
@uncheckedVariance
annotation, using this method might be unsound. However, as long as the returned builder is only fed withA
values taken fromthis
instance, it is safe.
- def nonEmpty: Boolean
Tests whether the weak hash map is not empty.
Tests whether the weak hash map is not empty.
- returns
true
if the weak hash map contains at least one element,false
otherwise.
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecatedOverriding()
- final def notify(): Unit
Wakes up a single thread that is waiting on the receiver object's monitor.
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.
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 orElse[A1 <: K, B1 >: V](that: PartialFunction[A1, B1]): PartialFunction[A1, B1]
Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.
Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.
- A1
the argument type of the fallback function
- B1
the result type of the fallback function
- that
the fallback function
- returns
a partial function which has as domain the union of the domains of this partial function and
that
. The resulting partial function takesx
tothis(x)
wherethis
is defined, and tothat(x)
where it is not.
- Definition Classes
- PartialFunction
- def partition(p: ((K, V)) => Boolean): (WeakHashMap[K, V], WeakHashMap[K, V])
A pair of, first, all elements that satisfy predicate
p
and, second, all elements that do not.A pair of, first, all elements that satisfy predicate
p
and, second, all elements that do not.The two weak hash map correspond to the result of filter and filterNot, respectively.
The default implementation provided here needs to traverse the collection twice. Strict collections have an overridden version of
partition
inStrictOptimizedIterableOps
, which requires only a single traversal.- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def partitionMap[A1, A2](f: ((K, V)) => Either[A1, A2]): (Iterable[A1], Iterable[A2])
Applies a function
f
to each element of the weak hash map and returns a pair of weak hash maps: the first one made of those values returned byf
that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.Applies a function
f
to each element of the weak hash map and returns a pair of weak hash maps: the first one made of those values returned byf
that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.Example:
val xs = `WeakHashMap`(1, "one", 2, "two", 3, "three") partitionMap { case i: Int => Left(i) case s: String => Right(s) } // xs == (`WeakHashMap`(1, 2, 3), // `WeakHashMap`(one, two, three))
- A1
the element type of the first resulting collection
- A2
the element type of the second resulting collection
- f
the 'split function' mapping the elements of this weak hash map to an scala.util.Either
- returns
a pair of weak hash maps: the first one made of those values returned by
f
that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def product[B >: (K, V)](implicit num: math.Numeric[B]): B
Multiplies together the elements of this collection.
Multiplies together the elements of this collection.
The default implementation uses
reduce
for a known non-empty collection,foldLeft
otherwise.- B
the result type of the
*
operator.- num
an implicit parameter defining a set of numeric operations which includes the
*
operator to be used in forming the product.- returns
the product of all elements of this weak hash map with respect to the
*
operator innum
.
- Definition Classes
- IterableOnceOps
- def put(k: K, v: V): Option[V]
Adds a new key/value pair to this map and optionally returns previously bound value.
Adds a new key/value pair to this map and optionally returns previously bound value. If the map already contains a mapping for the key, it will be overridden by the new value.
- returns
an option value containing the value associated with the key before the
put
operation was executed, orNone
ifkey
was not defined in the map before.
- Definition Classes
- JMapWrapperLike → MapOps
- def reduce[B >: (K, V)](op: (B, B) => B): B
Applies the given binary operator
op
to all elements of this weak hash map.Applies the given binary operator
op
to all elements of this weak hash map.For each application of the operator, each operand is either an element of this weak hash map or another such application of the operator. The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation.
If this collection is ordered, then for any application of the operator, the element(s) appearing in the left operand will precede those in the right.
Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative.
- B
The type parameter for the binary operator, a supertype of
A
.- op
A binary operator; must be associative for the result to always be the same across runs.
- returns
The result of applying
op
between all the elements if the weak hash map is nonempty.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this weak hash map is empty.
- def reduceLeft[B >: (K, V)](op: (B, (K, V)) => B): B
Applies the given binary operator
op
to all elements of this weak hash map, going left to right.Applies the given binary operator
op
to all elements of this weak hash map, going left to right."Going left to right" only makes sense if this collection is ordered: then if
x1
,x2
, ...,xn
are the elements of this weak hash map, the result isop( op( op( ... op(x1, x2) ... ), xn-1), xn)
.If this collection is not ordered, then for each application of the operator, each right operand is an element. In addition, the leftmost operand is the first element of this weak hash map and each other left operand is itself an application of the operator. Each element appears exactly once in the computation.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of applying
op
to all elements of this weak hash map, going left to right.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this weak hash map is empty.
- def reduceLeftOption[B >: (K, V)](op: (B, (K, V)) => B): Option[B]
If this weak hash map is nonempty, reduces it with the given binary operator
op
, going left to right.If this weak hash map is nonempty, reduces it with the given binary operator
op
, going left to right.The behavior is the same as reduceLeft except that the value is
None
if the weak hash map is empty. Each element appears exactly once in the computation.Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of reducing this weak hash map with
op
going left to right if the weak hash map is nonempty, inside aSome
, andNone
otherwise.
- Definition Classes
- IterableOnceOps
- def reduceOption[B >: (K, V)](op: (B, B) => B): Option[B]
If this weak hash map is nonempty, reduces it with the given binary operator
op
.If this weak hash map is nonempty, reduces it with the given binary operator
op
.The behavior is the same as reduce except that the value is
None
if the weak hash map is empty. The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation.Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative.
- B
A type parameter for the binary operator, a supertype of
A
.- op
A binary operator; must be associative for the result to always be the same across runs.
- returns
The result of reducing this weak hash map with
op
if the weak hash map is nonempty, inside aSome
, andNone
otherwise.
- Definition Classes
- IterableOnceOps
- def reduceRight[B >: (K, V)](op: ((K, V), B) => B): B
Applies the given binary operator
op
to all elements of this weak hash map, going right to left.Applies the given binary operator
op
to all elements of this weak hash map, going right to left."Going right to left" only makes sense if this collection is ordered: then if
x1
,x2
, ...,xn
are the elements of this weak hash map, the result isop(x1, op(x2, op( ... op(xn-1, xn) ... )))
.If this collection is not ordered, then for each application of the operator, each left operand is an element. In addition, the rightmost operand is the last element of this weak hash map and each other right operand is itself an application of the operator. Each element appears exactly once in the computation.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of applying
op
to all elements of this weak hash map, going right to left.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this weak hash map is empty.
- def reduceRightOption[B >: (K, V)](op: ((K, V), B) => B): Option[B]
If this weak hash map is nonempty, reduces it with the given binary operator
op
, going right to left.If this weak hash map is nonempty, reduces it with the given binary operator
op
, going right to left.The behavior is the same as reduceRight except that the value is
None
if the weak hash map is empty. Each element appears exactly once in the computation.Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of reducing this weak hash map with
op
going right to left if the weak hash map is nonempty, inside aSome
, andNone
otherwise.
- Definition Classes
- IterableOnceOps
- def remove(k: K): Option[V]
Removes a key from this map, returning the value associated previously with that key as an option.
Removes a key from this map, returning the value associated previously with that key as an option.
- returns
an option value containing the value associated previously with
key
, orNone
ifkey
was not defined in the map before.
- Definition Classes
- JMapWrapperLike → MapOps
- def result(): WeakHashMap[K, V]
Result collection consisting of all elements appended so far.
- def reversed: collection.Iterable[(K, V)]
- Attributes
- protected
- Definition Classes
- IterableOnceOps
- def runWith[U](action: (V) => U): (K) => Boolean
Composes this partial function with an action function which gets applied to results of this partial function.
Composes this partial function with an action function which gets applied to results of this partial function. The action function is invoked only for its side effects; its result is ignored.
Note that expression
pf.runWith(action)(x)
is equivalent toif(pf isDefinedAt x) { action(pf(x)); true } else false
except that
runWith
is implemented viaapplyOrElse
and thus potentially more efficient. UsingrunWith
avoids double evaluation of pattern matchers and guards for partial function literals.- action
the action function
- returns
a function which maps arguments
x
toisDefinedAt(x)
. The resulting function runsaction(this(x))
wherethis
is defined.
- Definition Classes
- PartialFunction
- See also
applyOrElse
.
- def scan[B >: (K, V)](z: B)(op: (B, B) => B): Iterable[B]
Computes a prefix scan of the elements of the collection.
Computes a prefix scan of the elements of the collection.
Note: The neutral element
z
may be applied more than once.- B
element type of the resulting collection
- z
neutral element for the operator
op
- op
the associative operator for the scan
- returns
a new weak hash map containing the prefix scan of the elements in this weak hash map
- Definition Classes
- IterableOps
- def scanLeft[B](z: B)(op: (B, (K, V)) => B): Iterable[B]
Produces a weak hash map containing cumulative results of applying the operator going left to right, including the initial value.
Produces a weak hash map containing cumulative results of applying the operator going left to right, including the initial value.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- B
the type of the elements in the resulting collection
- z
the initial value
- op
the binary operator applied to the intermediate result and the element
- returns
collection with intermediate results
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def scanRight[B](z: B)(op: ((K, V), B) => B): Iterable[B]
Produces a collection containing cumulative results of applying the operator going right to left.
Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.
Note: might return different results for different runs, unless the underlying collection type is ordered.
Note: Even when applied to a view or a lazy collection it will always force the elements.
Example:
List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)
- B
the type of the elements in the resulting collection
- z
the initial value
- op
the binary operator applied to the intermediate result and the element
- returns
collection with intermediate results
- Definition Classes
- IterableOps
- def size: Int
The size of this weak hash map.
The size of this weak hash map.
- returns
the number of elements in this weak hash map.
- Definition Classes
- JMapWrapperLike → IterableOnceOps
- def sizeCompare(that: collection.Iterable[_]): Int
Compares the size of this weak hash map to the size of another
Iterable
.Compares the size of this weak hash map to the size of another
Iterable
.- that
the
Iterable
whose size is compared with this weak hash map's size.- returns
A value
x
wherex < 0 if this.size < that.size x == 0 if this.size == that.size x > 0 if this.size > that.size
The method as implemented here does not call
size
directly; its running time isO(this.size min that.size)
instead ofO(this.size + that.size)
. The method should be overridden if computingsize
is cheap andknownSize
returns-1
.
- Definition Classes
- IterableOps
- def sizeCompare(otherSize: Int): Int
Compares the size of this weak hash map to a test value.
Compares the size of this weak hash map to a test value.
- otherSize
the test value that gets compared with the size.
- returns
A value
x
wherex < 0 if this.size < otherSize x == 0 if this.size == otherSize x > 0 if this.size > otherSize
The method as implemented here does not call
size
directly; its running time isO(size min otherSize)
instead ofO(size)
. The method should be overridden if computingsize
is cheap andknownSize
returns-1
.
- Definition Classes
- IterableOps
- See also
- final def sizeHint(coll: IterableOnce[_], delta: Int = 0): 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.
- 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).
- Definition Classes
- Builder
- 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.
- size
the hint how many elements will be added.
- Definition Classes
- Builder
- final def sizeHintBounded(size: Int, boundingColl: collection.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.- 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
- Builder
- final def sizeIs: SizeCompareOps
Returns a value class containing operations for comparing the size of this weak hash map to a test value.
Returns a value class containing operations for comparing the size of this weak hash map to a test value.
These operations are implemented in terms of
sizeCompare(Int)
, and allow the following more readable usages:this.sizeIs < size // this.sizeCompare(size) < 0 this.sizeIs <= size // this.sizeCompare(size) <= 0 this.sizeIs == size // this.sizeCompare(size) == 0 this.sizeIs != size // this.sizeCompare(size) != 0 this.sizeIs >= size // this.sizeCompare(size) >= 0 this.sizeIs > size // this.sizeCompare(size) > 0
- Definition Classes
- IterableOps
- Annotations
- @inline()
- def slice(from: Int, until: Int): WeakHashMap[K, V]
Selects an interval of elements.
Selects an interval of elements. The returned weak hash map is made up of all elements
x
which satisfy the invariant:from <= indexOf(x) < until
Note: might return different results for different runs, unless the underlying collection type is ordered.
- from
the lowest index to include from this weak hash map.
- until
the lowest index to EXCLUDE from this weak hash map.
- returns
a weak hash map containing the elements greater than or equal to index
from
extending up to (but not including) indexuntil
of this weak hash map.
- Definition Classes
- IterableOps → IterableOnceOps
- def sliding(size: Int, step: Int): Iterator[WeakHashMap[K, V]]
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in
grouped
).Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in
grouped
).The returned iterator will be empty when called on an empty collection. The last element the iterator produces may be smaller than the window size when the original collection isn't exhausted by the window before it and its last element isn't skipped by the step before it.
- size
the number of elements per group
- step
the distance between the first elements of successive groups
- returns
An iterator producing weak hash maps of size
size
, except the last element (which may be the only element) will be smaller if there are fewer thansize
elements remaining to be grouped.
- Definition Classes
- IterableOps
List(1, 2, 3, 4, 5).sliding(2, 2) = Iterator(List(1, 2), List(3, 4), List(5))
, List(1, 2, 3, 4, 5, 6).sliding(2, 3) = Iterator(List(1, 2), List(4, 5))
- See also
scala.collection.Iterator, method
sliding
Examples: - def sliding(size: Int): Iterator[WeakHashMap[K, V]]
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in
grouped
).Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in
grouped
).An empty collection returns an empty iterator, and a non-empty collection containing fewer elements than the window size returns an iterator that will produce the original collection as its only element.
- size
the number of elements per group
- returns
An iterator producing weak hash maps of size
size
, except for a non-empty collection with less thansize
elements, which returns an iterator that produces the source collection itself as its only element.
- Definition Classes
- IterableOps
List().sliding(2) = empty iterator
, List(1).sliding(2) = Iterator(List(1))
, List(1, 2).sliding(2) = Iterator(List(1, 2))
, List(1, 2, 3).sliding(2) = Iterator(List(1, 2), List(2, 3))
- See also
scala.collection.Iterator, method
sliding
Examples: - def span(p: ((K, V)) => Boolean): (WeakHashMap[K, V], WeakHashMap[K, V])
Splits this weak hash map into a prefix/suffix pair according to a predicate.
Splits this weak hash map into a prefix/suffix pair according to a predicate.
Note:
c span p
is equivalent to (but possibly more efficient than)(c takeWhile p, c dropWhile p)
, provided the evaluation of the predicatep
does not cause any side-effects.Note: might return different results for different runs, unless the underlying collection type is ordered.
- p
the test predicate
- returns
a pair consisting of the longest prefix of this weak hash map whose elements all satisfy
p
, and the rest of this weak hash map.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def splitAt(n: Int): (WeakHashMap[K, V], WeakHashMap[K, V])
Splits this weak hash map into a prefix/suffix pair at a given position.
Splits this weak hash map into a prefix/suffix pair at a given position.
Note:
c splitAt n
is equivalent to (but possibly more efficient than)(c take n, c drop n)
.Note: might return different results for different runs, unless the underlying collection type is ordered.
- n
the position at which to split.
- returns
a pair of weak hash maps consisting of the first
n
elements of this weak hash map, and the other elements.
- Definition Classes
- IterableOps → IterableOnceOps
- def stepper[S <: Stepper[_]](implicit shape: StepperShape[(K, V), S]): S
Returns a scala.collection.Stepper for the elements of this collection.
Returns a scala.collection.Stepper for the elements of this collection.
The Stepper enables creating a Java stream to operate on the collection, see scala.jdk.StreamConverters. For collections holding primitive values, the Stepper can be used as an iterator which doesn't box the elements.
The implicit scala.collection.StepperShape parameter defines the resulting Stepper type according to the element type of this collection.
- For collections of
Int
,Short
,Byte
orChar
, an scala.collection.IntStepper is returned - For collections of
Double
orFloat
, a scala.collection.DoubleStepper is returned - For collections of
Long
a scala.collection.LongStepper is returned - For any other element type, an scala.collection.AnyStepper is returned
Note that this method is overridden in subclasses and the return type is refined to
S with EfficientSplit
, for example scala.collection.IndexedSeqOps.stepper. For Steppers marked with scala.collection.Stepper.EfficientSplit, the converters in scala.jdk.StreamConverters allow creating parallel streams, whereas bare Steppers can be converted only to sequential streams.- Definition Classes
- IterableOnce
- For collections of
- final def strictOptimizedCollect[B, C2](b: Builder[B, C2], pf: PartialFunction[(K, V), B]): C2
- B
Type of elements of the resulting collection (e.g.
String
)- C2
Type of the resulting collection (e.g.
List[String]
)- b
Builder to use to build the resulting collection
- pf
Element transformation partial function
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- final def strictOptimizedConcat[B >: (K, V), C2](that: IterableOnce[B], b: Builder[B, C2]): C2
- B
Type of elements of the resulting collections (e.g.
Int
)- C2
Type of the resulting collection (e.g.
List[Int]
)- that
Elements to concatenate to this collection
- b
Builder to use to build the resulting collection
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- final def strictOptimizedFlatMap[B, C2](b: Builder[B, C2], f: ((K, V)) => IterableOnce[B]): C2
- B
Type of elements of the resulting collection (e.g.
String
)- C2
Type of the resulting collection (e.g.
List[String]
)- b
Builder to use to build the resulting collection
- f
Element transformation function
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- final def strictOptimizedFlatten[B, C2](b: Builder[B, C2])(implicit toIterableOnce: ((K, V)) => IterableOnce[B]): C2
- B
Type of elements of the resulting collection (e.g.
Int
)- C2
Type of the resulting collection (e.g.
List[Int]
)- b
Builder to use to build the resulting collection
- toIterableOnce
Evidence that
A
can be seen as anIterableOnce[B]
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- final def strictOptimizedMap[B, C2](b: Builder[B, C2], f: ((K, V)) => B): C2
- B
Type of elements of the resulting collection (e.g.
String
)- C2
Type of the resulting collection (e.g.
List[String]
)- b
Builder to use to build the resulting collection
- f
Element transformation function
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- final def strictOptimizedZip[B, C2](that: IterableOnce[B], b: Builder[((K, V), B), C2]): C2
- B
Type of elements of the second collection (e.g.
String
)- C2
Type of the resulting collection (e.g.
List[(Int, String)]
)- that
Collection to zip with this collection
- b
Builder to use to build the resulting collection
- returns
The resulting collection
- Attributes
- protected[this]
- Definition Classes
- StrictOptimizedIterableOps
- Annotations
- @inline()
- def stringPrefix: String
- Attributes
- protected[this]
- Definition Classes
- WeakHashMap → Map → Iterable
- Annotations
- @nowarn()
- def subtractAll(xs: IterableOnce[K]): WeakHashMap.this.type
Removes all elements produced by an iterator from this weak hash map.
Removes all elements produced by an iterator from this weak hash map.
- xs
the iterator producing the elements to remove.
- returns
the weak hash map itself
- Definition Classes
- Shrinkable
- def subtractOne(key: K): WeakHashMap.this.type
Removes a single element from this weak hash map.
Removes a single element from this weak hash map.
- returns
the weak hash map itself
- Definition Classes
- JMapWrapperLike → Shrinkable
- def sum[B >: (K, V)](implicit num: math.Numeric[B]): B
Sums the elements of this collection.
Sums the elements of this collection.
The default implementation uses
reduce
for a known non-empty collection,foldLeft
otherwise.- B
the result type of the
+
operator.- num
an implicit parameter defining a set of numeric operations which includes the
+
operator to be used in forming the sum.- returns
the sum of all elements of this weak hash map with respect to the
+
operator innum
.
- Definition Classes
- IterableOnceOps
- final def synchronized[T0](arg0: => T0): T0
Executes the code in
body
with an exclusive lock onthis
.Executes the code in
body
with an exclusive lock onthis
.- returns
the result of
body
- Definition Classes
- AnyRef
- def tail: WeakHashMap[K, V]
The rest of the collection without its first element.
The rest of the collection without its first element.
- Definition Classes
- IterableOps
- def tails: Iterator[WeakHashMap[K, V]]
Iterates over the tails of this weak hash map.
Iterates over the tails of this weak hash map. The first value will be this weak hash map and the final one will be an empty weak hash map, with the intervening values the results of successive applications of
tail
.- returns
an iterator over all the tails of this weak hash map
- Definition Classes
- IterableOps
List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)
Example: - def take(n: Int): WeakHashMap[K, V]
Selects the first
n
elements.Selects the first
n
elements.Note: might return different results for different runs, unless the underlying collection type is ordered.
- n
the number of elements to take from this weak hash map.
- returns
a weak hash map consisting only of the first
n
elements of this weak hash map, or else the whole weak hash map, if it has less thann
elements. Ifn
is negative, returns an empty weak hash map.
- Definition Classes
- IterableOps → IterableOnceOps
- def takeRight(n: Int): WeakHashMap[K, V]
A collection containing the last
n
elements of this collection.A collection containing the last
n
elements of this collection.Note: Even when applied to a view or a lazy collection it will always force the elements.
- n
the number of elements to take from this weak hash map.
- returns
a weak hash map consisting only of the last
n
elements of this weak hash map, or else the whole weak hash map, if it has less thann
elements. Ifn
is negative, returns an empty weak hash map.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def takeWhile(p: ((K, V)) => Boolean): WeakHashMap[K, V]
Takes longest prefix of elements that satisfy a predicate.
Takes longest prefix of elements that satisfy a predicate.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- p
The predicate used to test elements.
- returns
the longest prefix of this weak hash map whose elements all satisfy the predicate
p
.
- Definition Classes
- IterableOps → IterableOnceOps
- def tapEach[U](f: ((K, V)) => U): WeakHashMap[K, V]
Applies a side-effecting function to each element in this collection.
Applies a side-effecting function to each element in this collection. Strict collections will apply
f
to their elements immediately, while lazy collections like Views and LazyLists will only applyf
on each element if and when that element is evaluated, and each time that element is evaluated.- U
the return type of f
- f
a function to apply to each element in this weak hash map
- returns
The same logical collection as this
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
- def to[C1](factory: Factory[(K, V), C1]): C1
Given a collection factory
factory
, converts this weak hash map to the appropriate representation for the current element typeA
.Given a collection factory
factory
, converts this weak hash map to the appropriate representation for the current element typeA
. Example uses:xs.to(List) xs.to(ArrayBuffer) xs.to(BitSet) // for xs: Iterable[Int]
- Definition Classes
- IterableOnceOps
- def toArray[B >: (K, V)](implicit arg0: ClassTag[B]): Array[B]
Converts this weak hash map to an
Array
.Converts this weak hash map to an
Array
.Implementation note: DO NOT call Array.from from this method.
- B
The type of elements of the result, a supertype of
A
.- returns
This weak hash map as an
Array[B]
.
- Definition Classes
- IterableOnceOps
- final def toBuffer[B >: (K, V)]: Buffer[B]
Converts this weak hash map to a
Buffer
.Converts this weak hash map to a
Buffer
.- B
The type of elements of the result, a supertype of
A
.- returns
This weak hash map as a
Buffer[B]
.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- def toIndexedSeq: immutable.IndexedSeq[(K, V)]
Converts this weak hash map to an
IndexedSeq
.Converts this weak hash map to an
IndexedSeq
.- returns
This weak hash map as an
IndexedSeq[A]
.
- Definition Classes
- IterableOnceOps
- def toList: immutable.List[(K, V)]
Converts this weak hash map to a
List
.Converts this weak hash map to a
List
.- returns
This weak hash map as a
List[A]
.
- Definition Classes
- IterableOnceOps
- def toMap[K, V](implicit ev: <:<[(K, V), (K, V)]): immutable.Map[K, V]
Converts this weak hash map to a
Map
, given an implicit coercion from the weak hash map's type to a key-value tuple.Converts this weak hash map to a
Map
, given an implicit coercion from the weak hash map's type to a key-value tuple.- K
The key type for the resulting map.
- V
The value type for the resulting map.
- ev
An implicit coercion from
A
to[K, V]
.- returns
This weak hash map as a
Map[K, V]
.
- Definition Classes
- IterableOnceOps
- def toSeq: immutable.Seq[(K, V)]
- returns
This weak hash map as a
Seq[A]
. This is equivalent toto(Seq)
but might be faster.
- Definition Classes
- IterableOnceOps
- def toSet[B >: (K, V)]: immutable.Set[B]
Converts this weak hash map to a
Set
.Converts this weak hash map to a
Set
.- B
The type of elements of the result, a supertype of
A
.- returns
This weak hash map as a
Set[B]
.
- Definition Classes
- IterableOnceOps
- def toString(): String
Creates a String representation of this object.
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.
- def toVector: immutable.Vector[(K, V)]
Converts this weak hash map to a
Vector
.Converts this weak hash map to a
Vector
.- returns
This weak hash map as a
Vector[A]
.
- Definition Classes
- IterableOnceOps
- def transpose[B](implicit asIterable: ((K, V)) => collection.Iterable[B]): Iterable[Iterable[B]]
Transposes this weak hash map of iterable collections into a weak hash map of weak hash maps.
Transposes this weak hash map of iterable collections into a weak hash map of weak hash maps.
The resulting collection's type will be guided by the static type of weak hash map. For example:
val xs = List( Set(1, 2, 3), Set(4, 5, 6)).transpose // xs == List( // List(1, 4), // List(2, 5), // List(3, 6)) val ys = Vector( List(1, 2, 3), List(4, 5, 6)).transpose // ys == Vector( // Vector(1, 4), // Vector(2, 5), // Vector(3, 6))
Note: Even when applied to a view or a lazy collection it will always force the elements.
- B
the type of the elements of each iterable collection.
- asIterable
an implicit conversion which asserts that the element type of this weak hash map is an
Iterable
.- returns
a two-dimensional weak hash map of weak hash maps which has as nth row the nth column of this weak hash map.
- Definition Classes
- IterableOps
- Exceptions thrown
IllegalArgumentException
if all collections in this weak hash map are not of the same size.
- def unapply(a: K): Option[V]
Tries to extract a
B
from anA
in a pattern matching expression.Tries to extract a
B
from anA
in a pattern matching expression.- Definition Classes
- PartialFunction
- val underlying: java.util.Map[K, V]
- Definition Classes
- JMapWrapper → JMapWrapperLike
- def unlift: PartialFunction[K, B]
Converts an optional function to a partial function.
Converts an optional function to a partial function.
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toUnliftOps[K, B] performed by method UnliftOps in scala.Function1.This conversion will take place only if V is a subclass of Option[B] (V <: Option[B]).
- Definition Classes
- UnliftOps
Unlike Function.unlift, this UnliftOps.unlift method can be used in extractors.
val of: Int => Option[String] = { i => if (i == 2) { Some("matched by an optional function") } else { None } } util.Random.nextInt(4) match { case of.unlift(m) => // Convert an optional function to a pattern println(m) case _ => println("Not matched") }
Example: - def unzip[A1, A2](implicit asPair: ((K, V)) => (A1, A2)): (Iterable[A1], Iterable[A2])
Converts this weak hash map of pairs into two collections of the first and second half of each pair.
Converts this weak hash map of pairs into two collections of the first and second half of each pair.
val xs = `WeakHashMap`( (1, "one"), (2, "two"), (3, "three")).unzip // xs == (`WeakHashMap`(1, 2, 3), // `WeakHashMap`(one, two, three))
- A1
the type of the first half of the element pairs
- A2
the type of the second half of the element pairs
- asPair
an implicit conversion which asserts that the element type of this weak hash map is a pair.
- returns
a pair of weak hash maps, containing the first, respectively second half of each element pair of this weak hash map.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def unzip3[A1, A2, A3](implicit asTriple: ((K, V)) => (A1, A2, A3)): (Iterable[A1], Iterable[A2], Iterable[A3])
Converts this weak hash map of triples into three collections of the first, second, and third element of each triple.
Converts this weak hash map of triples into three collections of the first, second, and third element of each triple.
val xs = `WeakHashMap`( (1, "one", '1'), (2, "two", '2'), (3, "three", '3')).unzip3 // xs == (`WeakHashMap`(1, 2, 3), // `WeakHashMap`(one, two, three), // `WeakHashMap`(1, 2, 3))
- A1
the type of the first member of the element triples
- A2
the type of the second member of the element triples
- A3
the type of the third member of the element triples
- asTriple
an implicit conversion which asserts that the element type of this weak hash map is a triple.
- returns
a triple of weak hash maps, containing the first, second, respectively third member of each element triple of this weak hash map.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def update(k: K, v: V): Unit
Adds a new key/value pair to this map.
Adds a new key/value pair to this map. If the map already contains a mapping for the key, it will be overridden by the new value.
- Definition Classes
- JMapWrapperLike → MapOps
- def updateWith(key: K)(remappingFunction: (Option[V]) => Option[V]): Option[V]
Update a mapping for the specified key and its current optionally mapped value (
Some
if there is current mapping,None
if not).Update a mapping for the specified key and its current optionally mapped value (
Some
if there is current mapping,None
if not).If the remapping function returns
Some(v)
, the mapping is updated with the new valuev
. If the remapping function returnsNone
, the mapping is removed (or remains absent if initially absent). If the function itself throws an exception, the exception is rethrown, and the current mapping is left unchanged.- key
the key value
- remappingFunction
a function that receives current optionally mapped value and return a new mapping
- returns
the new value associated with the specified key
- Definition Classes
- JMapWrapperLike → MapOps
- def valueStepper[S <: Stepper[_]](implicit shape: StepperShape[V, S]): S
Returns a Stepper for the values of this map.
- def values: collection.Iterable[V]
Collects all values of this map in an iterable collection.
Collects all values of this map in an iterable collection.
- returns
the values of this map as an iterable.
- Definition Classes
- MapOps
- def valuesIterator: Iterator[V]
Creates an iterator for all values in this map.
Creates an iterator for all values in this map.
- returns
an iterator over all values that are associated with some key in this map.
- Definition Classes
- MapOps
- def view: MapView[K, V]
A view over the elements of this collection.
A view over the elements of this collection.
- Definition Classes
- MapOps → IterableOps
- final def wait(): Unit
See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--.
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- Note
not specified by SLS as a member of AnyRef
- final def wait(arg0: Long, arg1: Int): Unit
See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-int-
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- Note
not specified by SLS as a member of AnyRef
- final def wait(arg0: Long): Unit
See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-.
- def withDefault(d: (K) => V): Map[K, V]
The same map with a given default function.
The same map with a given default function. Note: The default is only used for
apply
. Other methods likeget
,contains
,iterator
,keys
, etc. are not affected bywithDefaultValue
.Invoking transformer methods (e.g.
map
) will not preserve the default value.- d
the function mapping keys to values, used for non-present keys
- returns
a wrapper of the map with a default value
- Definition Classes
- Map
- def withDefaultValue(d: V): Map[K, V]
The same map with a given default value.
The same map with a given default value. Note: The default is only used for
apply
. Other methods likeget
,contains
,iterator
,keys
, etc. are not affected bywithDefaultValue
.Invoking transformer methods (e.g.
map
) will not preserve the default value.- d
default value used for non-present keys
- returns
a wrapper of the map with a default value
- Definition Classes
- Map
- def withFilter(p: ((K, V)) => Boolean): MapOps.WithFilter[K, V, [x]Iterable[x], [x, y]WeakHashMap[x, y]]
Creates a non-strict filter of this weak hash map.
Creates a non-strict filter of this weak hash map.
Note: the difference between
c filter p
andc withFilter p
is that the former creates a new collection, whereas the latter only restricts the domain of subsequentmap
,flatMap
,foreach
, andwithFilter
operations.Note: might return different results for different runs, unless the underlying collection type is ordered.
- p
the predicate used to test elements.
- returns
an object of class
WithFilter
, which supportsmap
,flatMap
,foreach
, andwithFilter
operations. All these operations apply to those elements of this weak hash map which satisfy the predicatep
.
- Definition Classes
- MapFactoryDefaults → IterableOps
- def zip[B](that: IterableOnce[B]): Iterable[((K, V), B)]
Returns a weak hash map formed from this weak hash map and another iterable collection by combining corresponding elements in pairs.
Returns a weak hash map formed from this weak hash map and another iterable collection by combining corresponding elements in pairs. If one of the two collections is longer than the other, its remaining elements are ignored.
- B
the type of the second half of the returned pairs
- that
The iterable providing the second half of each result pair
- returns
a new weak hash map containing pairs consisting of corresponding elements of this weak hash map and
that
. The length of the returned collection is the minimum of the lengths of this weak hash map andthat
.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps
- def zipAll[A1 >: (K, V), B](that: collection.Iterable[B], thisElem: A1, thatElem: B): Iterable[(A1, B)]
Returns a weak hash map formed from this weak hash map and another iterable collection by combining corresponding elements in pairs.
Returns a weak hash map formed from this weak hash map and another iterable collection by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.
- that
the iterable providing the second half of each result pair
- thisElem
the element to be used to fill up the result if this weak hash map is shorter than
that
.- thatElem
the element to be used to fill up the result if
that
is shorter than this weak hash map.- returns
a new collection of type
That
containing pairs consisting of corresponding elements of this weak hash map andthat
. The length of the returned collection is the maximum of the lengths of this weak hash map andthat
. If this weak hash map is shorter thanthat
,thisElem
values are used to pad the result. Ifthat
is shorter than this weak hash map,thatElem
values are used to pad the result.
- Definition Classes
- IterableOps
- def zipWithIndex: Iterable[((K, V), Int)]
Zips this weak hash map with its indices.
Zips this weak hash map with its indices.
- returns
A new weak hash map containing pairs consisting of all elements of this weak hash map paired with their index. Indices start at
0
.
- Definition Classes
- StrictOptimizedIterableOps → IterableOps → IterableOnceOps
List("a", "b", "c").zipWithIndex == List(("a", 0), ("b", 1), ("c", 2))
Example:
Shadowed Implicit Value Members
- def +(other: String): String
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toany2stringadd[WeakHashMap[K, V]] performed by method any2stringadd in scala.Predef.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: any2stringadd[WeakHashMap[K, V]]).+(other)
- Definition Classes
- any2stringadd
Deprecated Value Members
- def +[V1 >: V](elem1: (K, V1), elem2: (K, V1), elems: (K, V1)*): WeakHashMap[K, V1]
- Definition Classes
- StrictOptimizedMapOps → MapOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use ++ with an explicit collection argument instead of + with varargs
- def +[V1 >: V](kv: (K, V1)): WeakHashMap[K, V1]
- Definition Classes
- MapOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Consider requiring an immutable Map or fall back to Map.concat.
- def ++:[V1 >: V](that: IterableOnce[(K, V1)]): WeakHashMap[K, V1]
- Definition Classes
- MapOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use ++ instead of ++: for collections of type Iterable
- def ++:[B >: (K, V)](that: IterableOnce[B]): Iterable[B]
- Definition Classes
- IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use ++ instead of ++: for collections of type Iterable
- final def +=(elem1: (K, V), elem2: (K, V), elems: (K, V)*): WeakHashMap.this.type
Adds two or more elements to this weak hash map.
Adds two or more elements to this weak hash map.
- elem1
the first element to add.
- elem2
the second element to add.
- elems
the remaining elements to add.
- returns
the weak hash map itself
- Definition Classes
- Growable
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use
++=
akaaddAll
instead of varargs+=
; infix operations with an operand of multiple args will be deprecated
- final def -(key1: K, key2: K, keys: K*): WeakHashMap[K, V]
- Definition Classes
- MapOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use -- or removeAll on an immutable Map
- final def -(key: K): WeakHashMap[K, V]
- Definition Classes
- MapOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use - or remove on an immutable Map
- def --(keys: IterableOnce[K]): WeakHashMap[K, V]
- Definition Classes
- MapOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Consider requiring an immutable Map.
- def -=(elem1: K, elem2: K, elems: K*): WeakHashMap.this.type
Removes two or more elements from this weak hash map.
Removes two or more elements from this weak hash map.
- elem1
the first element to remove.
- elem2
the second element to remove.
- elems
the remaining elements to remove.
- returns
the weak hash map itself
- Definition Classes
- Shrinkable
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.3) Use
--=
akasubtractAll
instead of varargs-=
; infix operations with an operand of multiple args will be deprecated
- def /:[B](z: B)(op: (B, (K, V)) => B): B
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)])./:(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldLeft instead
- final def /:[B](z: B)(op: (B, (K, V)) => B): B
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use foldLeft instead of /:
- def :\[B](z: B)(op: ((K, V), B) => B): B
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).:\(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldRight instead
- final def :\[B](z: B)(op: ((K, V), B) => B): B
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use foldRight instead of :\
- def aggregate[B](z: => B)(seqop: (B, (K, V)) => B, combop: (B, B) => B): B
Aggregates the results of applying an operator to subsequent elements.
Aggregates the results of applying an operator to subsequent elements.
Since this method degenerates to
foldLeft
for sequential (non-parallel) collections, where the combining operation is ignored, it is advisable to preferfoldLeft
for that case.For parallel collections, use the
aggregate
method specified byscala.collection.parallel.ParIterableLike
.- B
the result type, produced by
seqop
,combop
, and by this function as a final result.- z
the start value, a neutral element for
seqop
.- seqop
the binary operator used to accumulate the result.
- combop
an associative operator for combining sequential results, unused for sequential collections.
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) For sequential collections, prefer
foldLeft(z)(seqop)
. For parallel collections, useParIterableLike#aggregate
.
- def collectFirst[B](f: PartialFunction[(K, V), B]): Option[B]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).collectFirst(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.collectFirst(...) instead
- def companion: IterableFactory[[_]Iterable[_]]
- Definition Classes
- IterableOps
- Annotations
- @deprecated @deprecatedOverriding() @inline()
- Deprecated
(Since version 2.13.0) Use iterableFactory instead
- def copyToBuffer(dest: Buffer[(K, V)]): Unit
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).copyToBuffer(dest)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.copyToBuffer(...) instead
- final def copyToBuffer[B >: (K, V)](dest: Buffer[B]): Unit
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use
dest ++= coll
instead
- def count(f: ((K, V)) => Boolean): Int
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).count(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.count(...) instead
- def exists(f: ((K, V)) => Boolean): Boolean
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).exists(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.exists(...) instead
- def filter(f: ((K, V)) => Boolean): Iterator[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).filter(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.filter(...) instead
- def filterKeys(p: (K) => Boolean): MapView[K, V]
Filters this map by retaining only keys satisfying a predicate.
Filters this map by retaining only keys satisfying a predicate.
- p
the predicate used to test keys
- returns
an immutable map consisting only of those key value pairs of this map where the key satisfies the predicate
p
. The resulting map wraps the original map without copying any elements.
- Definition Classes
- MapOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .view.filterKeys(f). A future version will include a strict version of this method (for now, .view.filterKeys(p).toMap).
- def find(p: ((K, V)) => Boolean): Option[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.find instead
- def flatMap[B](f: ((K, V)) => IterableOnce[B]): IterableOnce[B]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.flatMap instead or consider requiring an Iterable
- def fold[A1 >: A](z: A1)(op: (A1, A1) => A1): A1
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).fold(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.fold instead
- def foldLeft[B](z: B)(op: (B, (K, V)) => B): B
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).foldLeft(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldLeft instead
- def foldRight[B](z: B)(op: ((K, V), B) => B): B
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).foldRight(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldRight instead
- def forall(f: ((K, V)) => Boolean): Boolean
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).forall(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.forall(...) instead
- def foreach[U](f: ((K, V)) => U): Unit
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).foreach(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foreach(...) instead
- def formatted(fmtstr: String): String
Returns string formatted according to given
format
string.Returns string formatted according to given
format
string. Format strings are as forString.format
(@see java.lang.String.format).- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toStringFormat[WeakHashMap[K, V]] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.12.16) Use
formatString.format(value)
instead ofvalue.formatted(formatString)
, or use thef""
string interpolator. In Java 15 and later,formatted
resolves to the new method in String which has reversed parameters.
- def hasDefiniteSize: Boolean
Tests whether this weak hash map is known to have a finite size.
Tests whether this weak hash map is known to have a finite size. All strict collections are known to have finite size. For a non-strict collection such as
Stream
, the predicate returnstrue
if all elements have been computed. It returnsfalse
if the stream is not yet evaluated to the end. Non-empty Iterators usually returnfalse
even if they were created from a collection with a known finite size.Note: many collection methods will not work on collections of infinite sizes. The typical failure mode is an infinite loop. These methods always attempt a traversal without checking first that
hasDefiniteSize
returnstrue
. However, checkinghasDefiniteSize
can provide an assurance that size is well-defined and non-termination is not a concern.- returns
true
if this collection is known to have finite size,false
otherwise.
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Check .knownSize instead of .hasDefiniteSize for more actionable information (see scaladoc for details)
- See also
method
knownSize
for a more useful alternative
- def isEmpty: Boolean
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).isEmpty
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.isEmpty instead
- def map[B](f: ((K, V)) => B): IterableOnce[B]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).map(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.map instead or consider requiring an Iterable
- def mapValues[W](f: (V) => W): MapView[K, W]
Transforms this map by applying a function to every retrieved value.
Transforms this map by applying a function to every retrieved value.
- f
the function used to transform values of this map.
- returns
a map view which maps every key of this map to
f(this(key))
. The resulting map wraps the original map without copying any elements.
- Definition Classes
- MapOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .view.mapValues(f). A future version will include a strict version of this method (for now, .view.mapValues(f).toMap).
- def max(implicit ord: math.Ordering[(K, V)]): (K, V)
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).max(ord)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.max instead
- def maxBy[B](f: ((K, V)) => B)(implicit cmp: math.Ordering[B]): (K, V)
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).maxBy(f)(cmp)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.maxBy(...) instead
- def min(implicit ord: math.Ordering[(K, V)]): (K, V)
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).min(ord)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.min instead
- def minBy[B](f: ((K, V)) => B)(implicit cmp: math.Ordering[B]): (K, V)
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).minBy(f)(cmp)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.minBy(...) instead
- def mkString: String
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).mkString
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.mkString instead
- def mkString(sep: String): String
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).mkString(sep)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.mkString instead
- def mkString(start: String, sep: String, end: String): String
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).mkString(start, sep, end)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.mkString instead
- def nonEmpty: Boolean
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).nonEmpty
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.nonEmpty instead
- def product(implicit num: math.Numeric[(K, V)]): (K, V)
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).product(num)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.product instead
- def reduce(f: ((K, V), (K, V)) => (K, V)): (K, V)
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).reduce(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduce(...) instead
- def reduceLeft(f: ((K, V), (K, V)) => (K, V)): (K, V)
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).reduceLeft(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduceLeft(...) instead
- def reduceLeftOption(f: ((K, V), (K, V)) => (K, V)): Option[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).reduceLeftOption(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduceLeftOption(...) instead
- def reduceOption(f: ((K, V), (K, V)) => (K, V)): Option[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).reduceOption(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduceOption(...) instead
- def reduceRight(f: ((K, V), (K, V)) => (K, V)): (K, V)
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).reduceRight(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduceRight(...) instead
- def reduceRightOption(f: ((K, V), (K, V)) => (K, V)): Option[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).reduceRightOption(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduceRightOption(...) instead
- final def repr: WeakHashMap[K, V]
- Definition Classes
- IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use coll instead of repr in a collection implementation, use the collection value itself from the outside
- final def retain(p: (K, V) => Boolean): WeakHashMap.this.type
- Definition Classes
- MapOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use filterInPlace instead
- def sameElements[B >: A](that: IterableOnce[B]): Boolean
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.sameElements instead
- def seq: WeakHashMap.this.type
- Definition Classes
- Iterable
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Iterable.seq always returns the iterable itself
- def size: Int
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).size
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.size instead
- def sum(implicit num: math.Numeric[(K, V)]): (K, V)
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).sum(num)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.sum instead
- def to[C1](factory: Factory[(K, V), C1]): C1
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).to(factory)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(factory) instead
- def toArray[B >: A](implicit arg0: ClassTag[B]): Array[B]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toArray(arg0)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.toArray
- def toBuffer[B >: A]: Buffer[B]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toBuffer
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(ArrayBuffer) instead
- def toIndexedSeq: collection.IndexedSeq[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toIndexedSeq
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.toIndexedSeq instead
- final def toIterable: collection.Iterable[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toIterable
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Iterable) instead
- final def toIterable: WeakHashMap.this.type
- returns
This collection as an
Iterable[A]
. No new collection will be built ifthis
is already anIterable[A]
.
- Definition Classes
- Iterable → IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.7) toIterable is internal and will be made protected; its name is similar to
toList
ortoSeq
, but it doesn't copy non-immutable collections
- def toIterator: Iterator[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toIterator
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator instead
- final def toIterator: Iterator[(K, V)]
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator instead of .toIterator
- def toList: immutable.List[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toList
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(List) instead
- def toMap[K, V](implicit ev: <:<[(K, V), (K, V)]): immutable.Map[K, V]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toMap(ev)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(Map) instead
- def toSeq: immutable.Seq[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toSeq
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Seq) instead
- def toSet[B >: A]: immutable.Set[B]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toSet
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Set) instead
- def toStream: immutable.Stream[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toStream
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(LazyList) instead
- final def toStream: immutable.Stream[(K, V)]
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .to(LazyList) instead of .toStream
- final def toTraversable: collection.Traversable[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toTraversable
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Iterable) instead
- final def toTraversable: collection.Traversable[(K, V)]
Converts this weak hash map to an unspecified Iterable.
Converts this weak hash map to an unspecified Iterable. Will return the same collection if this instance is already Iterable.
- returns
An Iterable containing all elements of this weak hash map.
- Definition Classes
- IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) toTraversable is internal and will be made protected; its name is similar to
toList
ortoSeq
, but it doesn't copy non-immutable collections
- def toVector: immutable.Vector[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).toVector
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Vector) instead
- final def transform(f: (K, V) => V): WeakHashMap.this.type
- Definition Classes
- MapOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use mapValuesInPlace instead
- def updated[V1 >: V](key: K, value: V1): WeakHashMap[K, V1]
- Definition Classes
- MapOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use m.clone().addOne((k,v)) instead of m.updated(k, v)
- def view(from: Int, until: Int): View[(K, V)]
A view over a slice of the elements of this collection.
A view over a slice of the elements of this collection.
- Definition Classes
- IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .view.slice(from, until) instead of .view(from, until)
- def withFilter(f: ((K, V)) => Boolean): Iterator[(K, V)]
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toIterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(weakHashMap: IterableOnceExtensionMethods[(K, V)]).withFilter(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.withFilter(...) instead
- def →[B](y: B): (WeakHashMap[K, V], B)
- Implicit
- This member is added by an implicit conversion from WeakHashMap[K, V] toArrowAssoc[WeakHashMap[K, V]] performed by method ArrowAssoc in scala.Predef.This conversion will take place only if V is a subclass of Option[Nothing] (V <: Option[Nothing]).
- Definition Classes
- ArrowAssoc
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use
->
instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.
This is the documentation for the Scala standard library.
Package structure
The scala package contains core types like
Int
,Float
,Array
orOption
which are accessible in all Scala compilation units without explicit qualification or imports.Notable packages include:
scala.collection
and its sub-packages contain Scala's collections frameworkscala.collection.immutable
- Immutable, sequential data-structures such asVector
,List
,Range
,HashMap
orHashSet
scala.collection.mutable
- Mutable, sequential data-structures such asArrayBuffer
,StringBuilder
,HashMap
orHashSet
scala.collection.concurrent
- Mutable, concurrent data-structures such asTrieMap
scala.concurrent
- Primitives for concurrent programming such asFutures
andPromises
scala.io
- Input and output operationsscala.math
- Basic math functions and additional numeric types likeBigInt
andBigDecimal
scala.sys
- Interaction with other processes and the operating systemscala.util.matching
- Regular expressionsOther packages exist. See the complete list on the right.
Additional parts of the standard library are shipped as separate libraries. These include:
scala.reflect
- Scala's reflection API (scala-reflect.jar)scala.xml
- XML parsing, manipulation, and serialization (scala-xml.jar)scala.collection.parallel
- Parallel collections (scala-parallel-collections.jar)scala.util.parsing
- Parser combinators (scala-parser-combinators.jar)scala.swing
- A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)Automatic imports
Identifiers in the scala package and the
scala.Predef
object are always in scope by default.Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example,
List
is an alias forscala.collection.immutable.List
.Other aliases refer to classes provided by the underlying platform. For example, on the JVM,
String
is an alias forjava.lang.String
.