HashMap

Companion object HashMap

sealed class HashMap[A, +B] extends AbstractMap[A, B] with Map[A, B] with MapLike[A, B, HashMap[A, B]] with Serializable with CustomParallelizable[(A, B), ParHashMap[A, B]] with HasForeachEntry[A, B]

This class implements immutable maps using a hash trie.

Note: The builder of this hash map may return specialized representations for small maps.

A: the type of the keys contained in this hash map.
B: the type of the values associated with the keys.

Annotations: @SerialVersionUID()
Source: HashMap.scala
Since: 2.3
See also: "Scala's Collection Library overview" section on Hash Tries for more information.

Linear Supertypes

HasForeachEntry[A, B], CustomParallelizable[(A, B), ParHashMap[A, B]], Serializable, java.io.Serializable, AbstractMap[A, B], Map[A, B], MapLike[A, B, HashMap[A, B]], Iterable[(A, B)], Traversable[(A, B)], Immutable, collection.AbstractMap[A, B], collection.Map[A, B], collection.MapLike[A, B, HashMap[A, B]], Subtractable[A, HashMap[A, B]], PartialFunction[A, B], (A) ⇒ B, GenMap[A, B], GenMapLike[A, B, HashMap[A, B]], AbstractIterable[(A, B)], collection.Iterable[(A, B)], IterableLike[(A, B), HashMap[A, B]], Equals, GenIterable[(A, B)], GenIterableLike[(A, B), HashMap[A, B]], AbstractTraversable[(A, B)], collection.Traversable[(A, B)], GenTraversable[(A, B)], GenericTraversableTemplate[(A, B), Iterable], TraversableLike[(A, B), HashMap[A, B]], GenTraversableLike[(A, B), HashMap[A, B]], Parallelizable[(A, B), ParHashMap[A, B]], TraversableOnce[(A, B)], GenTraversableOnce[(A, B)], FilterMonadic[(A, B), HashMap[A, B]], HasNewBuilder[(A, B), HashMap[A, B]], AnyRef, Any

Known Subclasses

HashMap1, HashTrieMap

Ordering

Alphabetic
By Inheritance

Inherited

HashMap
HasForeachEntry
CustomParallelizable
Serializable
Serializable
AbstractMap
Map
MapLike
Iterable
Traversable
Immutable
AbstractMap
Map
MapLike
Subtractable
PartialFunction
Function1
GenMap
GenMapLike
AbstractIterable
Iterable
IterableLike
Equals
GenIterable
GenIterableLike
AbstractTraversable
Traversable
GenTraversable
GenericTraversableTemplate
TraversableLike
GenTraversableLike
Parallelizable
TraversableOnce
GenTraversableOnce
FilterMonadic
HasNewBuilder
AnyRef
Any

Implicitly

by CollectionsHaveToParArray
by MonadOps
by any2stringadd
by StringFormat
by Ensuring
by ArrowAssoc
by alternateImplicit

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Visibility

Public
All

Instance Constructors

new HashMap()

Type Members

class DefaultKeySet extends AbstractSet[K] with Set[K] with Serializable
The implementation class of the set returned by keySet.
The implementation class of the set returned by keySet.

Attributes
protected
Definition Classes
MapLike
class DefaultValuesIterable extends AbstractIterable[V] with Iterable[V] with Serializable
The implementation class of the iterable returned by values.
The implementation class of the iterable returned by values.

Attributes
protected
Definition Classes
MapLike
class FilteredKeys extends AbstractMap[K, V] with DefaultMap[K, V]

Attributes
protected
Definition Classes
MapLike
class MappedValues[W] extends AbstractMap[K, W] with DefaultMap[K, W]

Attributes
protected
Definition Classes
MapLike
class WithFilter extends FilterMonadic[A, Repr]
A class supporting filtered operations.
A class supporting filtered operations. Instances of this class are returned by method withFilter.

Definition Classes
TraversableLike
type Self = HashMap[A, B]
The type implementing this traversable
The type implementing this traversable

Attributes
protected[this]
Definition Classes
TraversableLike
class ImmutableDefaultKeySet extends DefaultKeySet with Set[K]

Attributes
protected
Definition Classes
MapLike

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 and null.
Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.
returns
a hash value consistent with ==

Definition Classes
AnyRef → Any
def +[B1 >: B](elem1: (A, B1), elem2: (A, B1), elems: (A, B1)*): HashMap[A, B1]
Adds two or more elements to this collection and returns a new collection.
Adds two or more elements to this collection and returns a new collection.
elem1
the first element to add.
elem2
the second element to add.
elems
the remaining elements to add.
returns
A new map with the new bindings added to this map.

Definition Classes
HashMap → MapLike → MapLike
def +[B1 >: B](kv: (A, B1)): HashMap[A, B1]
Add a key/value pair to this map, returning a new map.
Add a key/value pair to this map, returning a new map.
kv
the key/value pair.
returns
A new map with the new binding added to this map.

Definition Classes
HashMap → Map → MapLike → MapLike → GenMapLike
def ++[C >: (A, B), That](that: GenTraversableOnce[C])(implicit bf: CanBuildFrom[HashMap[A, B], C, That]): That
Returns a new immutable hash map containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new immutable hash map containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the immutable hash map is the most specific superclass encompassing the element types of the two operands.
That
the class of the returned collection. Where possible, That is the same class as the current collection class Repr, but this depends on the element type B being admissible for that class, which means that an implicit instance of type CanBuildFrom[Repr, B, That] is found.
that
the traversable to append.
bf
an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.
returns
a new collection of type That which contains all elements of this immutable hash map followed by all elements of that.

Definition Classes
HashMap → TraversableLike → GenTraversableLike
def ++[B1 >: B](xs: GenTraversableOnce[(A, B1)]): Map[A, B1]
Adds a number of elements provided by a traversable object and returns a new collection with the added elements.
Adds a number of elements provided by a traversable object and returns a new collection with the added elements.
xs
the traversable object consisting of key-value pairs.
returns
a new immutable map with the bindings of this map and those from xs.

Definition Classes
HashMap → MapLike → MapLike
def ++:[C >: (A, B), That](that: scala.Traversable[C])(implicit bf: CanBuildFrom[HashMap[A, B], C, That]): That
As with ++, returns a new collection containing the elements from the left operand followed by the elements from the right operand.
As with ++, returns a new collection containing the elements from the left operand followed by the elements from the right operand.
It differs from ++ in that the right operand determines the type of the resulting collection rather than the left one. Mnemonic: the COLon is on the side of the new COLlection type.
Example:
```
scala> val x = List(1)
x: List[Int] = List(1)

scala> val y = LinkedList(2)
y: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

scala> val z = x ++: y
z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)
```
This overload exists because: for the implementation of ++: we should reuse that of ++ because many collections override it with more efficient versions.
Since TraversableOnce has no ++ method, we have to implement that directly, but Traversable and down can use the overload.
That
the class of the returned collection. Where possible, That is the same class as the current collection class Repr, but this depends on the element type B being admissible for that class, which means that an implicit instance of type CanBuildFrom[Repr, B, That] is found.
that
the traversable to append.
bf
an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.
returns
a new collection of type That which contains all elements of this immutable hash map followed by all elements of that.

Definition Classes
HashMap → TraversableLike
def ++:[B](that: TraversableOnce[B]): HashMap[B]
[use case] As with ++, returns a new collection containing the elements from the left operand followed by the elements from the right operand.
[use case]
As with ++, returns a new collection containing the elements from the left operand followed by the elements from the right operand.
It differs from ++ in that the right operand determines the type of the resulting collection rather than the left one. Mnemonic: the COLon is on the side of the new COLlection type.
Example:
```
scala> val x = List(1)
x: List[Int] = List(1)

scala> val y = LinkedList(2)
y: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

scala> val z = x ++: y
z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)
```
B
the element type of the returned collection.
that
the traversable to append.
returns
a new immutable hash map which contains all elements of this immutable hash map followed by all elements of that.

Definition Classes
HashMap → TraversableLike
Full Signature
def ++:[C >: (A, B), That](that: TraversableOnce[C])(implicit bf: CanBuildFrom[HashMap[A, B], C, That]): That
def -(key: K): collection.Map[K, V]
[use case] Removes a key from this map, returning a new map.
[use case]
Removes a key from this map, returning a new map.
key
the key to be removed
returns
a new map without a binding for key

Definition Classes
HashMap → MapLike → Subtractable → GenMapLike
Full Signature
def -(key: A): HashMap[A, B]
def -(elem1: A, elem2: A, elems: A*): HashMap[A, B]
Creates a new collection from this collection with some elements removed.
Creates a new collection from this collection with some elements removed.
This method takes two or more elements to be removed. Another overloaded variant of this method handles the case where a single element is removed.
elem1
the first element to remove.
elem2
the second element to remove.
elems
the remaining elements to remove.
returns
a new collection that contains all elements of the current collection except one less occurrence of each of the given elements.

Definition Classes
Subtractable
def --(xs: GenTraversableOnce[A]): HashMap[A, B]
Creates a new collection from this collection by removing all elements of another collection.
Creates a new collection from this collection by removing all elements of another collection.
xs
the collection containing the removed elements.
returns
a new collection that contains all elements of the current collection except one less occurrence of each of the elements of elems.

Definition Classes
Subtractable
def ->[B](y: B): (HashMap[A, B], B)

Implicit
This member is added by an implicit conversion from HashMap[A, B] to ArrowAssoc[HashMap[A, B]] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc
Annotations
@inline()
final def ==(arg0: Any): Boolean
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
returns
true if the receiver object is equivalent to the argument; false otherwise.

Definition Classes
AnyRef → Any
def addString(b: StringBuilder, start: String, sep: String, end: String): StringBuilder
Appends all bindings of this map to a string builder using start, end, and separator strings.
Appends all bindings of this map to a string builder using start, end, and separator strings. The written text begins with the string start and ends with the string end. Inside, the string representations of all bindings of this map in the form of key -> value are separated by the string sep.
b
the builder to which strings are appended.
start
the starting string.
sep
the separator string.
end
the ending string.
returns
the string builder b to which elements were appended.

Definition Classes
MapLike → TraversableOnce
def addString(b: StringBuilder): StringBuilder
Appends all elements of this traversable or iterator to a string builder.
Appends all elements of this traversable or iterator to a string builder. The written text consists of the string representations (w.r.t. the method toString) of all elements of this traversable or iterator 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
TraversableOnce
def addString(b: StringBuilder, sep: String): StringBuilder
Appends all elements of this traversable or iterator to a string builder using a separator string.
Appends all elements of this traversable or iterator 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 traversable or iterator, separated by the string sep.
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
TraversableOnce
def aggregate[B](z: ⇒ B)(seqop: (B, (A, B)) ⇒ 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.
This is a more general form of fold and reduce. It is similar to foldLeft in that it doesn't require the result to be a supertype of the element type. In addition, it allows parallel collections to be processed in chunks, and then combines the intermediate results.
aggregate splits the traversable or iterator into partitions and processes each partition by sequentially applying seqop, starting with z (like foldLeft). Those intermediate results are then combined by using combop (like fold). The implementation of this operation may operate on an arbitrary number of collection partitions (even 1), so combop may be invoked an arbitrary number of times (even 0).
As an example, consider summing up the integer values of a list of chars. The initial value for the sum is 0. First, seqop transforms each input character to an Int and adds it to the sum (of the partition). Then, combop just needs to sum up the intermediate results of the partitions:
```
List('a', 'b', 'c').aggregate(0)({ (sum, ch) => sum + ch.toInt }, { (p1, p2) => p1 + p2 })
```
B
the type of accumulated results
z
the initial value for the accumulated result of the partition - this will typically be the neutral element for the seqop operator (e.g. Nil for list concatenation or 0 for summation) and may be evaluated more than once
seqop
an operator used to accumulate results within a partition
combop
an associative operator used to combine results from different partitions

Definition Classes
TraversableOnce → GenTraversableOnce
def andThen[C](k: (B) ⇒ C): PartialFunction[A, 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.
C
the result type of the transformation function.
k
the transformation function
returns
a partial function with the same domain as this partial function, which maps arguments x to k(this(x)).

Definition Classes
PartialFunction → Function1
def apply(key: A): B
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, the default method throws a NoSuchElementException.
key
the key
returns
the value associated with the given key, or the result of the map's default method, if none exists.

Definition Classes
MapLike → GenMapLike → Function1
def applyOrElse[K1 <: A, V1 >: B](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 to
```
if(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 an applyOrElse implementation which avoids double evaluation of pattern matchers and guards. This makes applyOrElse the basis for the efficient implementation for many operations and scenarios, such as:
- combining partial functions into orElse/andThen chains does not lead to excessive apply/isDefinedAt evaluation
- lift and unlift do not evaluate source functions twice on each invocation
- runWith 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 override applyOrElse with custom implementation that avoids double isDefinedAt 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
MapLike → PartialFunction
Since
2.10
final def asInstanceOf[T0]: T0
Cast the receiver object to be of type T0.
Cast the receiver object to be of type T0.
Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.
returns
the receiver object.

Definition Classes
Any
Exceptions thrown
ClassCastException if the receiver object is not an instance of the erasure of type T0.
def canEqual(that: Any): Boolean
Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.
Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.
that
The object with which this iterable collection should be compared
returns
true, if this iterable collection can possibly equal that, false otherwise. The test takes into consideration only the run-time types of objects but ignores their elements.

Definition Classes
IterableLike → Equals
def clone(): AnyRef
Create a copy of the receiver object.
Create a copy of the receiver object.
The default implementation of the clone method is platform dependent.
returns
a copy of the receiver object.

Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws( ... ) @native()
Note
not specified by SLS as a member of AnyRef
def collect[B](pf: PartialFunction[A, B]): HashMap[B]
[use case] Builds a new collection by applying a partial function to all elements of this immutable hash map on which the function is defined.
[use case]
Builds a new collection by applying a partial function to all elements of this immutable hash map on which the function is defined.
B
the element type of the returned collection.
pf
the partial function which filters and maps the immutable hash map.
returns
a new immutable 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
TraversableLike → GenTraversableLike
Full Signature
def collect[B, That](pf: PartialFunction[(A, B), B])(implicit bf: CanBuildFrom[HashMap[A, B], B, That]): That
def collectFirst[B](pf: PartialFunction[(A, B), B]): Option[B]
Finds the first element of the traversable or iterator for which the given partial function is defined, and applies the partial function to it.
Finds the first element of the traversable or iterator for which the given partial function is defined, and applies the partial function to it.
Note: may not terminate for infinite-sized collections.
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
TraversableOnce
Example:
1. Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)
def companion: GenericCompanion[Iterable]
The factory companion object that builds instances of class immutable.Iterable.
The factory companion object that builds instances of class immutable.Iterable. (or its Iterable superclass where class immutable.Iterable is not a Seq.)

Definition Classes
Iterable → Iterable → GenIterable → Traversable → Traversable → GenTraversable → GenericTraversableTemplate
def compose[A](g: (A) ⇒ A): (A) ⇒ B
Composes two instances of Function1 in a new Function1, with this function applied last.
Composes two instances of Function1 in a new Function1, 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 that f(x) == apply(g(x))

Definition Classes
Function1
Annotations
@unspecialized()
final def contains(key: A): 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 for key in this map, false otherwise.

Definition Classes
HashMap → MapLike → GenMapLike
def contains0(key: A, hash: Int, level: Int): Boolean

Attributes
protected
def copyToArray(xs: Array[A], start: Int, len: Int): Unit
[use case] Copies the elements of this immutable hash map to an array.
[use case]
Copies the elements of this immutable hash map to an array. Fills the given array xs with at most len elements of this immutable hash map, starting at position start. Copying will stop once either the end of the current immutable hash map is reached, or the end of the target array is reached, or len elements have been copied.
xs
the array to fill.
start
the starting index.
len
the maximal number of elements to copy.

Definition Classes
IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce
Full Signature
def copyToArray[B >: (A, B)](xs: Array[B], start: Int, len: Int): Unit
def copyToArray(xs: Array[A]): Unit
[use case] Copies the elements of this immutable hash map to an array.
[use case]
Copies the elements of this immutable hash map to an array. Fills the given array xs with values of this immutable hash map. Copying will stop once either the end of the current immutable hash map is reached, or the end of the target array is reached.
xs
the array to fill.

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def copyToArray[B >: (A, B)](xs: Array[B]): Unit
def copyToArray(xs: Array[A], start: Int): Unit
[use case] Copies the elements of this immutable hash map to an array.
[use case]
Copies the elements of this immutable hash map to an array. Fills the given array xs with values of this immutable hash map, beginning at index start. Copying will stop once either the end of the current immutable hash map is reached, or the end of the target array is reached.
xs
the array to fill.
start
the starting index.

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def copyToArray[B >: (A, B)](xs: Array[B], start: Int): Unit
def copyToBuffer[B >: (A, B)](dest: Buffer[B]): Unit
Copies all elements of this traversable or iterator to a buffer.
Copies all elements of this traversable or iterator to a buffer.
Note: will not terminate for infinite-sized collections.
dest
The buffer to which elements are copied.

Definition Classes
TraversableOnce
def count(p: ((A, B)) ⇒ Boolean): Int
Counts the number of elements in the traversable or iterator which satisfy a predicate.
Counts the number of elements in the traversable or iterator which satisfy a predicate.
p
the predicate used to test elements.
returns
the number of elements satisfying the predicate p.

Definition Classes
TraversableOnce → GenTraversableOnce
def default(key: A): B
Defines the default value computation for the map, returned when a key is not found The method implemented here throws an exception, but it might be overridden in subclasses.
Defines the default value computation for the map, returned when a key is not found The method implemented here throws an exception, but it might be overridden in subclasses.
key
the given key value for which a binding is missing.

Definition Classes
MapLike → GenMapLike
Exceptions thrown
def drop(n: Int): HashMap[A, B]
Selects all elements except first n ones.
Selects all elements except 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 iterable collection.
returns
a iterable collection consisting of all elements of this iterable collection except the first n ones, or else the empty iterable collection, if this iterable collection has less than n elements. If n is negative, don't drop any elements.

Definition Classes
IterableLike → TraversableLike → GenTraversableLike
def dropRight(n: Int): HashMap[A, B]
Selects all elements except last n ones.
Selects all elements except last n ones.
Note: might return different results for different runs, unless the underlying collection type is ordered.
n
The number of elements to take
returns
a iterable collection consisting of all elements of this iterable collection except the last n ones, or else the empty iterable collection, if this iterable collection has less than n elements.

Definition Classes
IterableLike
def dropWhile(p: ((A, B)) ⇒ Boolean): HashMap[A, B]
Drops longest prefix of elements that satisfy a predicate.
Drops longest prefix of elements that satisfy a predicate.
Note: might return different results for different runs, unless the underlying collection type is ordered.
returns
the longest suffix of this traversable collection whose first element does not satisfy the predicate p.

Definition Classes
TraversableLike → GenTraversableLike
def elemHashCode(key: A): Int

Attributes
protected
def empty: HashMap[A, B]
The empty map of the same type as this map
The empty map of the same type as this map
returns
an empty map of type This.

Definition Classes
HashMap → Map → Map → MapLike
def ensuring(cond: (HashMap[A, B]) ⇒ Boolean, msg: ⇒ Any): HashMap[A, B]

Implicit
This member is added by an implicit conversion from HashMap[A, B] to Ensuring[HashMap[A, B]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
def ensuring(cond: (HashMap[A, B]) ⇒ Boolean): HashMap[A, B]

Implicit
This member is added by an implicit conversion from HashMap[A, B] to Ensuring[HashMap[A, B]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
def ensuring(cond: Boolean, msg: ⇒ Any): HashMap[A, B]

Implicit
This member is added by an implicit conversion from HashMap[A, B] to Ensuring[HashMap[A, B]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
def ensuring(cond: Boolean): HashMap[A, B]

Implicit
This member is added by an implicit conversion from HashMap[A, B] to Ensuring[HashMap[A, B]] 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 of AnyRef, and has three additional properties:
- It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.
- For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
- null.eq(null) returns true.
When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).
returns
true if the argument is a reference to the receiver object; false otherwise.

Definition Classes
AnyRef
def equals(that: Any): Boolean
Compares two maps structurally; i.e., checks if all mappings contained in this map are also contained in the other map, and vice versa.
Compares two maps structurally; i.e., checks if all mappings contained in this map are also contained in the other map, and vice versa.
that
the other map
returns
true if both maps contain exactly the same mappings, false otherwise.

Definition Classes
GenMapLike → Equals → AnyRef → Any
def exists(p: ((A, B)) ⇒ Boolean): Boolean
Tests whether a predicate holds for at least one element of this iterable collection.
Tests whether a predicate holds for at least one element of this iterable collection.
Note: may not terminate for infinite-sized collections.
p
the predicate used to test elements.
returns
false if this iterable collection is empty, otherwise true if the given predicate p holds for some of the elements of this iterable collection, otherwise false

Definition Classes
IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce
def filter(p: ((A, B)) ⇒ Boolean): HashMap[A, B]
Selects all elements of this immutable hash map which satisfy a predicate.
Selects all elements of this immutable hash map which satisfy a predicate.
p
the predicate used to test elements.
returns
a new immutable hash map consisting of all elements of this immutable hash map that satisfy the given predicate p. The order of the elements is preserved.

Definition Classes
HashMap → TraversableLike → GenTraversableLike
def filter0(p: ((A, B)) ⇒ Boolean, negate: Boolean, level: Int, buffer: Array[HashMap[A, B]], offset0: Int): HashMap[A, B]

Attributes
protected
def filterKeys(p: (A) ⇒ Boolean): Map[A, B]
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
MapLike → MapLike → GenMapLike
def filterNot(p: ((A, B)) ⇒ Boolean): HashMap[A, B]
Returns a new map obtained by removing all key/value pairs for which the predicate p returns true.
Returns a new map obtained by removing all key/value pairs for which the predicate p returns true.
Note: This method works by successively removing elements for which the predicate is true from this set. If removal is slow, or you expect that most elements of the set will be removed, you might consider using filter with a negated predicate instead.
p
A predicate over key-value pairs
returns
A new map containing elements not satisfying the predicate.

Definition Classes
HashMap → MapLike → TraversableLike → GenTraversableLike
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 between finalize and non-local returns and exceptions, are all platform dependent.

Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
Note
not specified by SLS as a member of AnyRef
def find(p: ((A, B)) ⇒ Boolean): Option[(A, B)]
Finds the first element of the iterable collection satisfying a predicate, if any.
Finds the first element of the iterable collection satisfying a predicate, if any.
Note: may not terminate for infinite-sized collections.
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 iterable collection that satisfies p, or None if none exists.

Definition Classes
IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce
def flatMap[B](f: (A) ⇒ GenTraversableOnce[B]): HashMap[B]
[use case] Builds a new collection by applying a function to all elements of this immutable hash map and using the elements of the resulting collections.
[use case]
Builds a new collection by applying a function to all elements of this immutable 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 immutable 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 => 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 immutable hash map resulting from applying the given collection-valued function f to each element of this immutable hash map and concatenating the results.

Definition Classes
TraversableLike → GenTraversableLike → FilterMonadic
Full Signature
def flatMap[B, That](f: ((A, B)) ⇒ GenTraversableOnce[B])(implicit bf: CanBuildFrom[HashMap[A, B], B, That]): That
def flatten[B]: HashMap[B]
[use case] Converts this immutable hash map of traversable collections into a immutable hash map formed by the elements of these traversable collections.
[use case]
Converts this immutable hash map of traversable collections into a immutable hash map formed by the elements of these traversable collections.
The resulting collection's type will be guided by the static type of immutable 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 traversable collection.
returns
a new immutable hash map resulting from concatenating all element immutable hash maps.

Definition Classes
GenericTraversableTemplate
Full Signature
def flatten[B](implicit asTraversable: ((A, B)) ⇒ GenTraversableOnce[B]): Iterable[B]
def fold[A1 >: (A, B)](z: A1)(op: (A1, A1) ⇒ A1): A1
Folds the elements of this traversable or iterator using the specified associative binary operator.
Folds the elements of this traversable or iterator using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
Note: will not terminate for infinite-sized collections.
A1
a type parameter for the binary operator, a supertype of A.
z
a neutral element for the fold operation; may be added to the result an arbitrary number of times, and must not change the result (e.g., Nil for list concatenation, 0 for addition, or 1 for multiplication).
op
a binary operator that must be associative.
returns
the result of applying the fold operator op between all the elements and z, or z if this traversable or iterator is empty.

Definition Classes
TraversableOnce → GenTraversableOnce
def foldLeft[B](z: B)(op: (B, (A, B)) ⇒ B): B
Applies a binary operator to a start value and all elements of this traversable or iterator, going left to right.
Applies a binary operator to a start value and all elements of this traversable or iterator, going left to right.
Note: will not terminate for infinite-sized collections.
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.
z
the start value.
op
the binary operator.
returns
the result of inserting op between consecutive elements of this traversable or iterator, going left to right with the start value z on the left:
```
op(...op(z, x_1), x_2, ..., x_n)
```
where x₁, ..., x_n are the elements of this traversable or iterator. Returns z if this traversable or iterator is empty.
Definition Classes
TraversableOnce → GenTraversableOnce
def foldRight[B](z: B)(op: ((A, B), B) ⇒ B): B
Applies a binary operator to all elements of this iterable collection and a start value, going right to left.
Applies a binary operator to all elements of this iterable collection and a start value, going right to left.
Note: will not terminate for infinite-sized collections.
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.
z
the start value.
op
the binary operator.
returns
the result of inserting op between consecutive elements of this iterable collection, going right to left with the start value z on the right:
```
op(x_1, op(x_2, ... op(x_n, z)...))
```
where x₁, ..., x_n are the elements of this iterable collection. Returns z if this iterable collection is empty.
Definition Classes
IterableLike → TraversableOnce → GenTraversableOnce
def forall(p: ((A, B)) ⇒ Boolean): Boolean
Tests whether a predicate holds for all elements of this iterable collection.
Tests whether a predicate holds for all elements of this iterable collection.
Note: may not terminate for infinite-sized collections.
p
the predicate used to test elements.
returns
true if this iterable collection is empty or the given predicate p holds for all elements of this iterable collection, otherwise false.

Definition Classes
IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce
def foreach(f: (A) ⇒ Unit): Unit
[use case] Applies a function f to all elements of this immutable hash map.
[use case]
Applies a function f to all elements of this immutable hash map.
Note: this method underlies the implementation of most other bulk operations. Subclasses should re-implement this method if a more efficient implementation exists.
f
the function that is applied for its side-effect to every element. The result of function f is discarded.

Definition Classes
HashMap → IterableLike → GenericTraversableTemplate → TraversableLike → GenTraversableLike → TraversableOnce → GenTraversableOnce → FilterMonadic
Full Signature
def foreach[U](f: ((A, B)) ⇒ U): Unit
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 for String.format (@see java.lang.String.format).

Implicit
This member is added by an implicit conversion from HashMap[A, B] to StringFormat[HashMap[A, B]] performed by method StringFormat in scala.Predef.
Definition Classes
StringFormat
Annotations
@inline()
def genericBuilder[B]: Builder[B, Iterable[B]]
The generic builder that builds instances of Traversable at arbitrary element types.
The generic builder that builds instances of Traversable at arbitrary element types.

Definition Classes
GenericTraversableTemplate
def get(key: A): Option[B]
Optionally returns the value associated with a key.
Optionally returns the value associated with a key.
key
the key value
returns
an option value containing the value associated with key in this map, or None if none exists.

Definition Classes
HashMap → MapLike → GenMapLike
final def getClass(): Class[_]
Returns the runtime class representation of the object.
Returns the runtime class representation of the object.
returns
a class object corresponding to the runtime type of the receiver.

Definition Classes
AnyRef → Any
Annotations
@native()
def getOrElse(key: A, default: ⇒ B): B
[use case] Returns the value associated with a key, or a default value if the key is not contained in the map.
[use case]
Returns the value associated with a key, or a default value if the key is not contained in the map.
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 the default computation.

Definition Classes
MapLike → GenMapLike
Full Signature
def getOrElse[V1 >: B](key: A, default: ⇒ V1): V1
def groupBy[K](f: ((A, B)) ⇒ K): Map[K, HashMap[A, B]]
Partitions this traversable collection into a map of traversable collections according to some discriminator function.
Partitions this traversable collection into a map of traversable collections according to some discriminator function.
Note: this method is not re-implemented by views. This means when applied to a view it will always force the view and return a new traversable collection.
K
the type of keys returned by the discriminator function.
f
the discriminator function.
returns
A map from keys to traversable collections 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 traversable collection of those elements x for which f(x) equals k.
Definition Classes
TraversableLike → GenTraversableLike
def grouped(size: Int): Iterator[HashMap[A, B]]
Partitions elements in fixed size iterable collections.
Partitions elements in fixed size iterable collections.
size
the number of elements per group
returns
An iterator producing iterable collections of size size, except the last will be less than size size if the elements don't divide evenly.

Definition Classes
IterableLike
See also
scala.collection.Iterator, method grouped
def hasDefiniteSize: Boolean
Tests whether this traversable collection is known to have a finite size.
Tests whether this traversable collection 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 returns true if all elements have been computed. It returns false if the stream is not yet evaluated to the end. Non-empty Iterators usually return false 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 returns true. However, checking hasDefiniteSize 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
TraversableLike → TraversableOnce → GenTraversableOnce
def hashCode(): Int
The hashCode method for reference types.
The hashCode method for reference types. See hashCode in scala.Any.
returns
the hash code value for this object.

Definition Classes
HashMap → GenMapLike → AnyRef → Any
def head: (A, B)
Selects the first element of this iterable collection.
Selects the first element of this iterable collection.
Note: might return different results for different runs, unless the underlying collection type is ordered.
returns
the first element of this iterable collection.

Definition Classes
IterableLike → TraversableLike → GenTraversableLike
Exceptions thrown
NoSuchElementException if the iterable collection is empty.
def headOption: Option[(A, B)]
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 traversable collection if it is nonempty, None if it is empty.

Definition Classes
TraversableLike → GenTraversableLike
final def improve(hcode: Int): Int

Attributes
protected
def init: HashMap[A, B]
Selects all elements except the last.
Selects all elements except the last.
Note: might return different results for different runs, unless the underlying collection type is ordered.
returns
a traversable collection consisting of all elements of this traversable collection except the last one.

Definition Classes
TraversableLike → GenTraversableLike
Exceptions thrown
UnsupportedOperationException if the traversable collection is empty.
def inits: Iterator[HashMap[A, B]]
Iterates over the inits of this traversable collection.
Iterates over the inits of this traversable collection. The first value will be this traversable collection and the final one will be an empty traversable collection, with the intervening values the results of successive applications of init.
returns
an iterator over all the inits of this traversable collection
Definition Classes
TraversableLike
Example:
1. List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)
def isDefinedAt(key: A): 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 to contains.
key
the key
returns
true if there is a binding for key in this map, false otherwise.

Definition Classes
MapLike → GenMapLike → PartialFunction
def isEmpty: Boolean
Tests whether the map is empty.
Tests whether the map is empty.
returns
true if the map does not contain any key/value binding, false otherwise.

Definition Classes
MapLike → IterableLike → TraversableLike → TraversableOnce → GenTraversableOnce
final def isInstanceOf[T0]: Boolean
Test whether the dynamic type of the receiver object is T0.
Test whether the dynamic type of the receiver object is T0.
Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.
returns
true if the receiver object is an instance of erasure of type T0; false otherwise.

Definition Classes
Any
final def isTraversableAgain: Boolean
Tests whether this traversable collection can be repeatedly traversed.
Tests whether this traversable collection can be repeatedly traversed.
returns
true

Definition Classes
TraversableLike → GenTraversableLike → GenTraversableOnce
def iterator: Iterator[(A, B)]
Creates a new iterator over all key/value pairs of this map
Creates a new iterator over all key/value pairs of this map
returns
the new iterator

Definition Classes
HashMap → MapLike → IterableLike → GenIterableLike
def keySet: Set[A]
Collects all keys of this map in a set.
Collects all keys of this map in a set.
returns
a set containing all keys of this map.

Definition Classes
HashMap → MapLike → MapLike → GenMapLike
def keys: collection.Iterable[A]
Collects all keys of this map in an iterable collection.
Collects all keys of this map in an iterable collection.
returns
the keys of this map as an iterable.

Definition Classes
MapLike → GenMapLike
Annotations
@migration
Migration
(Changed in version 2.8.0) keys returns Iterable[K] rather than Iterator[K].
def keysIterator: Iterator[A]
Creates an iterator for all keys.
Creates an iterator for all keys.
returns
an iterator over all keys.

Definition Classes
MapLike → GenMapLike
def last: (A, B)
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 traversable collection.

Definition Classes
TraversableLike → GenTraversableLike
Exceptions thrown
NoSuchElementException If the traversable collection is empty.
def lastOption: Option[(A, B)]
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 traversable collection$ if it is nonempty, None if it is empty.

Definition Classes
TraversableLike → GenTraversableLike
def lift: (A) ⇒ Option[B]
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 to Some(this(x)) if this is defined for x, and to None otherwise.

Definition Classes
PartialFunction
See also
Function.unlift
def map[B](f: (A) ⇒ B): HashMap[B]
[use case] Builds a new collection by applying a function to all elements of this immutable hash map.
[use case]
Builds a new collection by applying a function to all elements of this immutable hash map.
B
the element type of the returned collection.
f
the function to apply to each element.
returns
a new immutable hash map resulting from applying the given function f to each element of this immutable hash map and collecting the results.

Definition Classes
TraversableLike → GenTraversableLike → FilterMonadic
Full Signature
def map[B, That](f: ((A, B)) ⇒ B)(implicit bf: CanBuildFrom[HashMap[A, B], B, That]): That
def mapValues[W](f: (B) ⇒ W): Map[A, 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
MapLike → MapLike → GenMapLike
def max: A
[use case] Finds the largest element.
[use case]
Finds the largest element.
returns
the largest element of this immutable hash map.

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def max[B >: (A, B)](implicit cmp: Ordering[B]): (A, B)

Exceptions thrown
UnsupportedOperationException if this immutable hash map is empty.
def maxBy[B](f: (A) ⇒ B): A
[use case] Finds the first element which yields the largest value measured by function f.
[use case]
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 immutable hash map with the largest value measured by function f.

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def maxBy[B](f: ((A, B)) ⇒ B)(implicit cmp: Ordering[B]): (A, B)

Exceptions thrown
UnsupportedOperationException if this immutable hash map is empty.
def merge0[B1 >: B](that: HashMap[A, B1], level: Int, merger: Merger[A, B1]): HashMap[A, B1]

Attributes
protected
def merged[B1 >: B](that: HashMap[A, B1])(mergef: MergeFunction[A, B1]): HashMap[A, B1]
Creates a new map which is the merge of this and the argument hash map.
Creates a new map which is the merge of this and the argument hash map.
Uses the specified collision resolution function if two keys are the same. The collision resolution function will always take the first argument from this hash map and the second from that.
The merged method is on average more performant than doing a traversal and reconstructing a new immutable hash map from scratch.
B1
the value type of the other hash map
that
the other hash map
mergef
the merge function or null if the first key-value pair is to be picked
def min: A
[use case] Finds the smallest element.
[use case]
Finds the smallest element.
returns
the smallest element of this immutable hash map

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def min[B >: (A, B)](implicit cmp: Ordering[B]): (A, B)

Exceptions thrown
UnsupportedOperationException if this immutable hash map is empty.
def minBy[B](f: (A) ⇒ B): A
[use case] Finds the first element which yields the smallest value measured by function f.
[use case]
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 immutable hash map with the smallest value measured by function f.

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def minBy[B](f: ((A, B)) ⇒ B)(implicit cmp: Ordering[B]): (A, B)

Exceptions thrown
UnsupportedOperationException if this immutable hash map is empty.
def mkString: String
Displays all elements of this traversable or iterator in a string.
Displays all elements of this traversable or iterator in a string.
returns
a string representation of this traversable or iterator. In the resulting string the string representations (w.r.t. the method toString) of all elements of this traversable or iterator follow each other without any separator string.

Definition Classes
TraversableOnce → GenTraversableOnce
def mkString(sep: String): String
Displays all elements of this traversable or iterator in a string using a separator string.
Displays all elements of this traversable or iterator in a string using a separator string.
sep
the separator string.
returns
a string representation of this traversable or iterator. In the resulting string the string representations (w.r.t. the method toString) of all elements of this traversable or iterator are separated by the string sep.
Definition Classes
TraversableOnce → GenTraversableOnce
Example:
1. List(1, 2, 3).mkString("|") = "1|2|3"
def mkString(start: String, sep: String, end: String): String
Displays all elements of this traversable or iterator in a string using start, end, and separator strings.
Displays all elements of this traversable or iterator in a string using start, end, and separator strings.
start
the starting string.
sep
the separator string.
end
the ending string.
returns
a string representation of this traversable or iterator. The resulting string begins with the string start and ends with the string end. Inside, the string representations (w.r.t. the method toString) of all elements of this traversable or iterator are separated by the string sep.
Definition Classes
TraversableOnce → GenTraversableOnce
Example:
1. List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
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 newBuilder: Builder[(A, B), HashMap[A, B]]
A common implementation of newBuilder for all maps in terms of empty.
A common implementation of newBuilder for all maps in terms of empty. Overridden for mutable maps in mutable.MapLike.

Attributes
protected[this]
Definition Classes
MapLike → TraversableLike → HasNewBuilder
def nonEmpty: Boolean
Tests whether the traversable or iterator is not empty.
Tests whether the traversable or iterator is not empty.
returns
true if the traversable or iterator contains at least one element, false otherwise.

Definition Classes
TraversableOnce → GenTraversableOnce
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 <: A, B1 >: B](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 takes x to this(x) where this is defined, and to that(x) where it is not.

Definition Classes
PartialFunction
def par: ParHashMap[A, B]
Returns a parallel implementation of this collection.
Returns a parallel implementation of this collection.
For most collection types, this method creates a new parallel collection by copying all the elements. For these collection, par takes linear time. Mutable collections in this category do not produce a mutable parallel collection that has the same underlying dataset, so changes in one collection will not be reflected in the other one.
Specific collections (e.g. ParArray or mutable.ParHashMap) override this default behaviour by creating a parallel collection which shares the same underlying dataset. For these collections, par takes constant or sublinear time.
All parallel collections return a reference to themselves.
returns
a parallel implementation of this collection

Definition Classes
HashMap → CustomParallelizable → Parallelizable
def parCombiner: Combiner[(A, B), ParHashMap[A, B]]
The default par implementation uses the combiner provided by this method to create a new parallel collection.
The default par implementation uses the combiner provided by this method to create a new parallel collection.
returns
a combiner for the parallel collection of type ParRepr

Attributes
protected[this]
Definition Classes
CustomParallelizable → Parallelizable
def partition(p: ((A, B)) ⇒ Boolean): (HashMap[A, B], HashMap[A, B])
Partitions this traversable collection in two traversable collections according to a predicate.
Partitions this traversable collection in two traversable collections according to a predicate.
p
the predicate on which to partition.
returns
a pair of traversable collections: the first traversable collection consists of all elements that satisfy the predicate p and the second traversable collection consists of all elements that don't. The relative order of the elements in the resulting traversable collections is the same as in the original traversable collection.

Definition Classes
TraversableLike → GenTraversableLike
def product: A
[use case] Multiplies up the elements of this collection.
[use case]
Multiplies up the elements of this collection.
returns
the product of all elements in this immutable hash map of numbers of type Int. Instead of Int, any other type T with an implicit Numeric[T] implementation can be used as element type of the immutable hash map and as result type of product. Examples of such types are: Long, Float, Double, BigInt.

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def product[B >: (A, B)](implicit num: Numeric[B]): B
def reduce[A1 >: (A, B)](op: (A1, A1) ⇒ A1): A1
Reduces the elements of this traversable or iterator using the specified associative binary operator.
Reduces the elements of this traversable or iterator using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
A1
A type parameter for the binary operator, a supertype of A.
op
A binary operator that must be associative.
returns
The result of applying reduce operator op between all the elements if the traversable or iterator is nonempty.

Definition Classes
TraversableOnce → GenTraversableOnce
Exceptions thrown
UnsupportedOperationException if this traversable or iterator is empty.
def reduceLeft[B >: (A, B)](op: (B, (A, B)) ⇒ B): B
Applies a binary operator to all elements of this traversable or iterator, going left to right.
Applies a binary operator to all elements of this traversable or iterator, going left to right.
Note: will not terminate for infinite-sized collections.
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.
op
the binary operator.
returns
the result of inserting op between consecutive elements of this traversable or iterator, going left to right:
```
op( op( ... op(x_1, x_2) ..., x_{n-1}), x_n)
```
where x₁, ..., x_n are the elements of this traversable or iterator.
Definition Classes
TraversableOnce
Exceptions thrown
UnsupportedOperationException if this traversable or iterator is empty.
def reduceLeftOption[B >: (A, B)](op: (B, (A, B)) ⇒ B): Option[B]
Optionally applies a binary operator to all elements of this traversable or iterator, going left to right.
Optionally applies a binary operator to all elements of this traversable or iterator, going left to right.
Note: will not terminate for infinite-sized collections.
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.
op
the binary operator.
returns
an option value containing the result of reduceLeft(op) if this traversable or iterator is nonempty, None otherwise.

Definition Classes
TraversableOnce → GenTraversableOnce
def reduceOption[A1 >: (A, B)](op: (A1, A1) ⇒ A1): Option[A1]
Reduces the elements of this traversable or iterator, if any, using the specified associative binary operator.
Reduces the elements of this traversable or iterator, if any, using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
A1
A type parameter for the binary operator, a supertype of A.
op
A binary operator that must be associative.
returns
An option value containing result of applying reduce operator op between all the elements if the collection is nonempty, and None otherwise.

Definition Classes
TraversableOnce → GenTraversableOnce
def reduceRight[B >: (A, B)](op: ((A, B), B) ⇒ B): B
Applies a binary operator to all elements of this iterable collection, going right to left.
Applies a binary operator to all elements of this iterable collection, going right to left.
Note: will not terminate for infinite-sized collections.
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.
op
the binary operator.
returns
the result of inserting op between consecutive elements of this iterable collection, going right to left:
```
op(x_1, op(x_2, ..., op(x_{n-1}, x_n)...))
```
where x₁, ..., x_n are the elements of this iterable collection.
Definition Classes
IterableLike → TraversableOnce → GenTraversableOnce
Exceptions thrown
UnsupportedOperationException if this iterable collection is empty.
def reduceRightOption[B >: (A, B)](op: ((A, B), B) ⇒ B): Option[B]
Optionally applies a binary operator to all elements of this traversable or iterator, going right to left.
Optionally applies a binary operator to all elements of this traversable or iterator, going right to left.
Note: will not terminate for infinite-sized collections.
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.
op
the binary operator.
returns
an option value containing the result of reduceRight(op) if this traversable or iterator is nonempty, None otherwise.

Definition Classes
TraversableOnce → GenTraversableOnce
def removed0(key: A, hash: Int, level: Int): HashMap[A, B]

Attributes
protected
def repr: HashMap[A, B]
The collection of type traversable collection underlying this TraversableLike object.
The collection of type traversable collection underlying this TraversableLike object. By default this is implemented as the TraversableLike object itself, but this can be overridden.

Definition Classes
TraversableLike → GenTraversableLike
def reversed: scala.List[(A, B)]

Attributes
protected[this]
Definition Classes
TraversableOnce
def runWith[U](action: (B) ⇒ U): (A) ⇒ 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 to
```
if(pf isDefinedAt x) { action(pf(x)); true } else false
```
except that runWith is implemented via applyOrElse and thus potentially more efficient. Using runWith avoids double evaluation of pattern matchers and guards for partial function literals.
action
the action function
returns
a function which maps arguments x to isDefinedAt(x). The resulting function runs action(this(x)) where this is defined.

Definition Classes
PartialFunction
Since
2.10
See also
applyOrElse.
def sameElements(that: GenIterable[A]): Boolean
[use case] Checks if the other iterable collection contains the same elements in the same order as this immutable hash map.
[use case]
Checks if the other iterable collection contains the same elements in the same order as this immutable hash map.
Note: might return different results for different runs, unless the underlying collection type is ordered.
that
the collection to compare with.
returns
true, if both collections contain the same elements in the same order, false otherwise.

Definition Classes
IterableLike → GenIterableLike
Full Signature
def sameElements[B >: (A, B)](that: GenIterable[B]): Boolean
def scan[B >: (A, B), That](z: B)(op: (B, B) ⇒ B)(implicit cbf: CanBuildFrom[HashMap[A, B], B, That]): That
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
That
type of the resulting collection
z
neutral element for the operator op
op
the associative operator for the scan
cbf
combiner factory which provides a combiner
returns
a new traversable collection containing the prefix scan of the elements in this traversable collection

Definition Classes
TraversableLike → GenTraversableLike
def scanLeft[B, That](z: B)(op: (B, (A, B)) ⇒ B)(implicit bf: CanBuildFrom[HashMap[A, B], B, That]): That
Produces a collection containing cumulative results of applying the operator going left to right.
Produces a collection containing cumulative results of applying the operator going left to right.
Note: will not terminate for infinite-sized collections.
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
That
the actual type of the resulting collection
z
the initial value
op
the binary operator applied to the intermediate result and the element
bf
an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.
returns
collection with intermediate results

Definition Classes
TraversableLike → GenTraversableLike
def scanRight[B, That](z: B)(op: ((A, B), B) ⇒ B)(implicit bf: CanBuildFrom[HashMap[A, B], B, That]): That
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: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered.
Example:
```
List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)
```
B
the type of the elements in the resulting collection
That
the actual type of the resulting collection
z
the initial value
op
the binary operator applied to the intermediate result and the element
bf
an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.
returns
collection with intermediate results

Definition Classes
TraversableLike → GenTraversableLike
Annotations
@migration
Migration
(Changed in version 2.9.0) The behavior of scanRight has changed. The previous behavior can be reproduced with scanRight.reverse.
def seq: Map[A, B]
A version of this collection with all of the operations implemented sequentially (i.e., in a single-threaded manner).
A version of this collection with all of the operations implemented sequentially (i.e., in a single-threaded manner).
This method returns a reference to this collection. In parallel collections, it is redefined to return a sequential implementation of this collection. In both cases, it has O(1) complexity.
returns
a sequential view of the collection.

Definition Classes
Map → Map → GenMap → GenMapLike → Iterable → Iterable → GenIterable → Traversable → Traversable → GenTraversable → Parallelizable → TraversableOnce → GenTraversableOnce
def size: Int
The size of this immutable hash map.
The size of this immutable hash map.
returns
the number of elements in this immutable hash map.

Definition Classes
HashMap → GenTraversableLike → TraversableOnce → GenTraversableOnce
def sizeHintIfCheap: Int
The size of this collection or iterator, if it can be cheaply computed
The size of this collection or iterator, if it can be cheaply computed
returns
the number of elements in this collection or iterator, or -1 if the size cannot be determined cheaply

Attributes
protected[collection]
Definition Classes
GenTraversableOnce
def slice(from: Int, until: Int): HashMap[A, B]
Selects an interval of elements.
Selects an interval of elements. The returned collection 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.
returns
a iterable collection containing the elements greater than or equal to index from extending up to (but not including) index until of this iterable collection.

Definition Classes
IterableLike → TraversableLike → GenTraversableLike
def sliding(size: Int, step: Int): Iterator[HashMap[A, B]]
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.)
size
the number of elements per group
step
the distance between the first elements of successive groups
returns
An iterator producing iterable collections of size size, except the last element (which may be the only element) will be truncated if there are fewer than size elements remaining to be grouped.

Definition Classes
IterableLike
See also
scala.collection.Iterator, method sliding
def sliding(size: Int): Iterator[HashMap[A, B]]
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.) The "sliding window" step is set to one.
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.) The "sliding window" step is set to one.
size
the number of elements per group
returns
An iterator producing iterable collections of size size, except the last element (which may be the only element) will be truncated if there are fewer than size elements remaining to be grouped.

Definition Classes
IterableLike
See also
scala.collection.Iterator, method sliding
def span(p: ((A, B)) ⇒ Boolean): (HashMap[A, B], HashMap[A, B])
Splits this traversable collection into a prefix/suffix pair according to a predicate.
Splits this traversable collection 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 predicate p does not cause any side-effects.
Note: might return different results for different runs, unless the underlying collection type is ordered.
returns
a pair consisting of the longest prefix of this traversable collection whose elements all satisfy p, and the rest of this traversable collection.

Definition Classes
TraversableLike → GenTraversableLike
def split: Seq[HashMap[A, B]]
def splitAt(n: Int): (HashMap[A, B], HashMap[A, B])
Splits this traversable collection into two at a given position.
Splits this traversable collection into two 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 traversable collections consisting of the first n elements of this traversable collection, and the other elements.

Definition Classes
TraversableLike → GenTraversableLike
def stringPrefix: String
Defines the prefix of this object's toString representation.
Defines the prefix of this object's toString representation.
returns
a string representation which starts the result of toString applied to this map. Unless overridden in subclasses, the string prefix of every map is "Map".

Definition Classes
MapLike → TraversableLike → GenTraversableLike
def sum: A
[use case] Sums up the elements of this collection.
[use case]
Sums up the elements of this collection.
returns
the sum of all elements in this immutable hash map of numbers of type Int. Instead of Int, any other type T with an implicit Numeric[T] implementation can be used as element type of the immutable hash map and as result type of sum. Examples of such types are: Long, Float, Double, BigInt.

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def sum[B >: (A, B)](implicit num: Numeric[B]): B
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
def tail: HashMap[A, B]
Selects all elements except the first.
Selects all elements except the first.
Note: might return different results for different runs, unless the underlying collection type is ordered.
returns
a immutable hash map consisting of all elements of this immutable hash map except the first one.

Definition Classes
HashMap → TraversableLike → GenTraversableLike
Exceptions thrown
java.lang.UnsupportedOperationException if the immutable hash map is empty.
def tails: Iterator[HashMap[A, B]]
Iterates over the tails of this traversable collection.
Iterates over the tails of this traversable collection. The first value will be this traversable collection and the final one will be an empty traversable collection, with the intervening values the results of successive applications of tail.
returns
an iterator over all the tails of this traversable collection
Definition Classes
TraversableLike
Example:
1. List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)
def take(n: Int): HashMap[A, B]
Selects first n elements.
Selects 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 iterable collection.
returns
a iterable collection consisting only of the first n elements of this iterable collection, or else the whole iterable collection, if it has less than n elements. If n is negative, returns an empty iterable collection.

Definition Classes
IterableLike → TraversableLike → GenTraversableLike
def takeRight(n: Int): HashMap[A, B]
Selects last n elements.
Selects last n elements.
Note: might return different results for different runs, unless the underlying collection type is ordered.
n
the number of elements to take
returns
a iterable collection consisting only of the last n elements of this iterable collection, or else the whole iterable collection, if it has less than n elements.

Definition Classes
IterableLike
def takeWhile(p: ((A, B)) ⇒ Boolean): HashMap[A, B]
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.
returns
the longest prefix of this iterable collection whose elements all satisfy the predicate p.

Definition Classes
IterableLike → TraversableLike → GenTraversableLike
def thisCollection: collection.Iterable[(A, B)]
The underlying collection seen as an instance of Iterable.
The underlying collection seen as an instance of Iterable. By default this is implemented as the current collection object itself, but this can be overridden.

Attributes
protected[this]
Definition Classes
IterableLike → TraversableLike
def to[Col[_]]: Col[A]
[use case] Converts this immutable hash map into another by copying all elements.
[use case]
Converts this immutable hash map into another by copying all elements.
Col
The collection type to build.
returns
a new collection containing all elements of this immutable hash map.

Definition Classes
TraversableLike → TraversableOnce → GenTraversableOnce
Full Signature
def to[Col[_]](implicit cbf: CanBuildFrom[Nothing, (A, B), Col[(A, B)]]): Col[(A, B)]
def toArray: Array[A]
[use case] Converts this immutable hash map to an array.
[use case]
Converts this immutable hash map to an array.
returns
an array containing all elements of this immutable hash map. An ClassTag must be available for the element type of this immutable hash map.

Definition Classes
TraversableOnce → GenTraversableOnce
Full Signature
def toArray[B >: (A, B)](implicit arg0: ClassTag[B]): Array[B]
def toBuffer[E >: (A, B)]: Buffer[E]
Uses the contents of this map to create a new mutable buffer.
Uses the contents of this map to create a new mutable buffer.
returns
a buffer containing all elements of this map.

Definition Classes
MapLike → TraversableOnce → GenTraversableOnce
def toCollection(repr: HashMap[A, B]): collection.Iterable[(A, B)]
A conversion from collections of type Repr to Iterable objects.
A conversion from collections of type Repr to Iterable objects. By default this is implemented as just a cast, but this can be overridden.

Attributes
protected[this]
Definition Classes
IterableLike → TraversableLike
def toIndexedSeq: IndexedSeq[(A, B)]
Converts this traversable or iterator to an indexed sequence.
Converts this traversable or iterator to an indexed sequence.
Note: will not terminate for infinite-sized collections.
returns
an indexed sequence containing all elements of this traversable or iterator.

Definition Classes
TraversableOnce → GenTraversableOnce
def toIterable: collection.Iterable[(A, B)]
Returns this iterable collection as an iterable collection.
Returns this iterable collection as an iterable collection.
A new collection will not be built; lazy collections will stay lazy.
Note: will not terminate for infinite-sized collections.
returns
an Iterable containing all elements of this iterable collection.

Definition Classes
IterableLike → TraversableOnce → GenTraversableOnce
def toIterator: Iterator[(A, B)]
Returns an Iterator over the elements in this iterable collection.
Returns an Iterator over the elements in this iterable collection. Produces the same result as iterator.
Note: will not terminate for infinite-sized collections.
returns
an Iterator containing all elements of this iterable collection.

Definition Classes
IterableLike → TraversableLike → GenTraversableOnce
Annotations
@deprecatedOverriding( message = ... , since = "2.11.0" )
def toList: scala.List[(A, B)]
Converts this traversable or iterator to a list.
Converts this traversable or iterator to a list.
Note: will not terminate for infinite-sized collections.
returns
a list containing all elements of this traversable or iterator.

Definition Classes
TraversableOnce → GenTraversableOnce
def toMap[T, U](implicit ev: <:<[(A, B), (T, U)]): Map[T, U]
Returns this immutable map as an immutable map.
Returns this immutable map as an immutable map.
A new map will not be built; lazy collections will stay lazy.
returns
a map containing all elements of this immutable map.

Definition Classes
Map → TraversableOnce → GenTraversableOnce
Annotations
@deprecatedOverriding( message = ... , since = "2.11.0" )
def toParArray: ParArray[T]

Implicit
This member is added by an implicit conversion from HashMap[A, B] to CollectionsHaveToParArray[HashMap[A, B], T] performed by method CollectionsHaveToParArray in scala.collection.parallel. This conversion will take place only if an implicit value of type (HashMap[A, B]) ⇒ GenTraversableOnce[T] is in scope.
Definition Classes
CollectionsHaveToParArray
def toSeq: collection.Seq[(A, B)]
Converts this map to a sequence.
Converts this map to a sequence. As with toIterable, it's lazy in this default implementation, as this TraversableOnce may be lazy and unevaluated.
returns
a sequence containing all elements of this map.

Definition Classes
MapLike → TraversableOnce → GenTraversableOnce
def toSet[B >: (A, B)]: Set[B]
Converts this traversable or iterator to a set.
Converts this traversable or iterator to a set.
Note: will not terminate for infinite-sized collections.
returns
a set containing all elements of this traversable or iterator.

Definition Classes
TraversableOnce → GenTraversableOnce
def toStream: Stream[(A, B)]
Converts this iterable collection to a stream.
Converts this iterable collection to a stream.
returns
a stream containing all elements of this iterable collection.

Definition Classes
IterableLike → TraversableLike → GenTraversableOnce
def toString(): String
Converts this map to a string.
Converts this map to a string.
returns
a string representation of this collection. By default this string consists of the stringPrefix of this map, followed by all elements separated by commas and enclosed in parentheses.

Definition Classes
MapLike → TraversableLike → Function1 → AnyRef → Any
def toTraversable: collection.Traversable[(A, B)]
Converts this traversable collection to an unspecified Traversable.
Converts this traversable collection to an unspecified Traversable. Will return the same collection if this instance is already Traversable.
Note: will not terminate for infinite-sized collections.
returns
a Traversable containing all elements of this traversable collection.

Definition Classes
TraversableLike → TraversableOnce → GenTraversableOnce
Annotations
@deprecatedOverriding( message = ... , since = "2.11.0" )
def toVector: scala.Vector[(A, B)]
Converts this traversable or iterator to a Vector.
Converts this traversable or iterator to a Vector.
Note: will not terminate for infinite-sized collections.
returns
a vector containing all elements of this traversable or iterator.

Definition Classes
TraversableOnce → GenTraversableOnce
final def transform[W, That](f: (A, B) ⇒ W)(implicit bf: CanBuildFrom[HashMap[A, B], (A, W), That]): That
This function transforms all the values of mappings contained in this map with function f.
This function transforms all the values of mappings contained in this map with function f.
f
A function over keys and values
returns
the updated map

Definition Classes
HashMap → MapLike
def transformImpl[W](f: (A, B) ⇒ W): HashMap[A, W]

Attributes
protected
def transpose[B](implicit asTraversable: ((A, B)) ⇒ GenTraversableOnce[B]): Iterable[Iterable[B]]
Transposes this collection of traversable collections into a collection of collections.
Transposes this collection of traversable collections into a collection of collections.
The resulting collection's type will be guided by the static type of collection. 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))
```
B
the type of the elements of each traversable collection.
asTraversable
an implicit conversion which asserts that the element type of this collection is a Traversable.
returns
a two-dimensional collection of collections which has as nth row the nth column of this collection.

Definition Classes
GenericTraversableTemplate
Annotations
@migration
Migration
(Changed in version 2.9.0) transpose throws an IllegalArgumentException if collections are not uniformly sized.
Exceptions thrown
IllegalArgumentException if all collections in this collection are not of the same size.
def unzip[A1, A2](implicit asPair: ((A, B)) ⇒ (A1, A2)): (Iterable[A1], Iterable[A2])
Converts this collection of pairs into two collections of the first and second half of each pair.
Converts this collection of pairs into two collections of the first and second half of each pair.
```
val xs = Traversable(
           (1, "one"),
           (2, "two"),
           (3, "three")).unzip
// xs == (Traversable(1, 2, 3),
//        Traversable(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 collection is a pair.
returns
a pair of collections, containing the first, respectively second half of each element pair of this collection.

Definition Classes
GenericTraversableTemplate
def unzip3[A1, A2, A3](implicit asTriple: ((A, B)) ⇒ (A1, A2, A3)): (Iterable[A1], Iterable[A2], Iterable[A3])
Converts this collection of triples into three collections of the first, second, and third element of each triple.
Converts this collection of triples into three collections of the first, second, and third element of each triple.
```
val xs = Traversable(
           (1, "one", '1'),
           (2, "two", '2'),
           (3, "three", '3')).unzip3
// xs == (Traversable(1, 2, 3),
//        Traversable(one, two, three),
//        Traversable(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 collection is a triple.
returns
a triple of collections, containing the first, second, respectively third member of each element triple of this collection.

Definition Classes
GenericTraversableTemplate
def updated[B1 >: B](key: A, value: B1): HashMap[A, B1]
Add a key/value pair to this map.
Add a key/value pair to this map.
key
the key
value
the value
returns
A new map with the new binding added to this map

Definition Classes
HashMap → Map → MapLike → MapLike → GenMap
def values: collection.Iterable[B]
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
HashMap → MapLike → GenMapLike
def valuesIterator: Iterator[B]
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
MapLike → GenMapLike
def view(from: Int, until: Int): IterableView[(A, B), HashMap[A, B]]
Creates a non-strict view of a slice of this iterable collection.
Creates a non-strict view of a slice of this iterable collection.
Note: the difference between view and slice is that view produces a view of the current iterable collection, whereas slice produces a new iterable collection.
Note: view(from, to) is equivalent to view.slice(from, to)
Note: might return different results for different runs, unless the underlying collection type is ordered.
from
the index of the first element of the view
until
the index of the element following the view
returns
a non-strict view of a slice of this iterable collection, starting at index from and extending up to (but not including) index until.

Definition Classes
IterableLike → TraversableLike
def view: IterableView[(A, B), HashMap[A, B]]
Creates a non-strict view of this iterable collection.
Creates a non-strict view of this iterable collection.
returns
a non-strict view of this iterable collection.

Definition Classes
IterableLike → TraversableLike
final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... ) @native()
def withDefault[V1 >: B](d: (A) ⇒ V1): Map[A, V1]
The same map with a given default function.
The same map with a given default function. Note: get, contains, iterator, keys, etc are not affected by withDefault.
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[V1 >: B](d: V1): Map[A, V1]
The same map with a given default value.
The same map with a given default value. Note: get, contains, iterator, keys, etc are not affected by withDefaultValue.
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: ((A, B)) ⇒ Boolean): FilterMonadic[(A, B), HashMap[A, B]]
Creates a non-strict filter of this traversable collection.
Creates a non-strict filter of this traversable collection.
Note: the difference between c filter p and c withFilter p is that the former creates a new collection, whereas the latter only restricts the domain of subsequent map, flatMap, foreach, and withFilter 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 supports map, flatMap, foreach, and withFilter operations. All these operations apply to those elements of this traversable collection which satisfy the predicate p.

Definition Classes
TraversableLike → FilterMonadic
def writeReplace(): AnyRef

Attributes
protected
def zip[B](that: GenIterable[B]): HashMap[(A, B)]
[use case] Returns a immutable hash map formed from this immutable hash map and another iterable collection by combining corresponding elements in pairs.
[use case]
Returns a immutable hash map formed from this immutable 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.
Note: might return different results for different runs, unless the underlying collection type is ordered.
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 immutable hash map containing pairs consisting of corresponding elements of this immutable hash map and that. The length of the returned collection is the minimum of the lengths of this immutable hash map and that.

Definition Classes
IterableLike → GenIterableLike
Full Signature
def zip[A1 >: (A, B), B, That](that: GenIterable[B])(implicit bf: CanBuildFrom[HashMap[A, B], (A1, B), That]): That
def zipAll[B](that: collection.Iterable[B], thisElem: A, thatElem: B): HashMap[(A, B)]
[use case] Returns a immutable hash map formed from this immutable hash map and another iterable collection by combining corresponding elements in pairs.
[use case]
Returns a immutable hash map formed from this immutable 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.
Note: might return different results for different runs, unless the underlying collection type is ordered.
B
the type of the second half of the returned pairs
that
The iterable providing the second half of each result pair
thisElem
the element to be used to fill up the result if this immutable hash map is shorter than that.
thatElem
the element to be used to fill up the result if that is shorter than this immutable hash map.
returns
a new immutable hash map containing pairs consisting of corresponding elements of this immutable hash map and that. The length of the returned collection is the maximum of the lengths of this immutable hash map and that. If this immutable hash map is shorter than that, thisElem values are used to pad the result. If that is shorter than this immutable hash map, thatElem values are used to pad the result.

Definition Classes
IterableLike → GenIterableLike
Full Signature
def zipAll[B, A1 >: (A, B), That](that: GenIterable[B], thisElem: A1, thatElem: B)(implicit bf: CanBuildFrom[HashMap[A, B], (A1, B), That]): That
def zipWithIndex: HashMap[(A, Int)]
[use case] Zips this immutable hash map with its indices.
[use case]
Zips this immutable hash map with its indices.
Note: might return different results for different runs, unless the underlying collection type is ordered.
returns
A new immutable hash map containing pairs consisting of all elements of this immutable hash map paired with their index. Indices start at 0.
Definition Classes
IterableLike → GenIterableLike
Full Signature
def zipWithIndex[A1 >: (A, B), That](implicit bf: CanBuildFrom[HashMap[A, B], (A1, Int), That]): That
Example:
1. List("a", "b", "c").zipWithIndex = List(("a", 0), ("b", 1), ("c", 2))
def →[B](y: B): (HashMap[A, B], B)

Implicit
This member is added by an implicit conversion from HashMap[A, B] to ArrowAssoc[HashMap[A, B]] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc

Shadowed Implicit Value Members

def +(other: String): String
Implicit
This member is added by an implicit conversion from HashMap[A, B] to any2stringadd[HashMap[A, B]] 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:
(hashMap: any2stringadd[HashMap[A, B]]).+(other)
Definition Classes
any2stringadd
def filter(p: ((A, B)) ⇒ Boolean): TraversableOnce[(A, B)]
Implicit
This member is added by an implicit conversion from HashMap[A, B] to MonadOps[(A, B)] performed by method MonadOps in scala.collection.TraversableOnce.
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:
(hashMap: MonadOps[(A, B)]).filter(p)
Definition Classes
MonadOps
def flatMap[B](f: ((A, B)) ⇒ GenTraversableOnce[B]): TraversableOnce[B]
Implicit
This member is added by an implicit conversion from HashMap[A, B] to MonadOps[(A, B)] performed by method MonadOps in scala.collection.TraversableOnce.
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:
(hashMap: MonadOps[(A, B)]).flatMap(f)
Definition Classes
MonadOps
def map[B](f: ((A, B)) ⇒ B): TraversableOnce[B]
Implicit
This member is added by an implicit conversion from HashMap[A, B] to MonadOps[(A, B)] performed by method MonadOps in scala.collection.TraversableOnce.
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:
(hashMap: MonadOps[(A, B)]).map(f)
Definition Classes
MonadOps
def withFilter(p: ((A, B)) ⇒ Boolean): Iterator[(A, B)]
Implicit
This member is added by an implicit conversion from HashMap[A, B] to MonadOps[(A, B)] performed by method MonadOps in scala.collection.TraversableOnce.
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:
(hashMap: MonadOps[(A, B)]).withFilter(p)
Definition Classes
MonadOps

Deprecated Value Members

def /:[B](z: B)(op: (B, (A, B)) ⇒ B): B
Applies a binary operator to a start value and all elements of this traversable or iterator, going left to right.
Applies a binary operator to a start value and all elements of this traversable or iterator, going left to right.
Note: /: is alternate syntax for foldLeft; z /: xs is the same as xs foldLeft z.
Examples:
Note that the folding function used to compute b is equivalent to that used to compute c.
```
scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = (5 /: a)(_+_)
b: Int = 15

scala> val c = (5 /: a)((x,y) => x + y)
c: Int = 15
```
Note: will not terminate for infinite-sized collections.
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.
z
the start value.
op
the binary operator.
returns
the result of inserting op between consecutive elements of this traversable or iterator, going left to right with the start value z on the left:
```
op(...op(op(z, x_1), x_2), ..., x_n)
```
where x₁, ..., x_n are the elements of this traversable or iterator.
Definition Classes
TraversableOnce → GenTraversableOnce
Annotations
@deprecated
Deprecated
(Since version 2.12.10) Use foldLeft instead of /:
def :\[B](z: B)(op: ((A, B), B) ⇒ B): B
Applies a binary operator to all elements of this traversable or iterator and a start value, going right to left.
Applies a binary operator to all elements of this traversable or iterator and a start value, going right to left.
Note: :\ is alternate syntax for foldRight; xs :\ z is the same as xs foldRight z.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
Examples:
Note that the folding function used to compute b is equivalent to that used to compute c.
```
scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = (a :\ 5)(_+_)
b: Int = 15

scala> val c = (a :\ 5)((x,y) => x + y)
c: Int = 15
```
B
the result type of the binary operator.
z
the start value
op
the binary operator
returns
the result of inserting op between consecutive elements of this traversable or iterator, going right to left with the start value z on the right:
```
op(x_1, op(x_2, ... op(x_n, z)...))
```
where x₁, ..., x_n are the elements of this traversable or iterator.
Definition Classes
TraversableOnce → GenTraversableOnce
Annotations
@deprecated
Deprecated
(Since version 2.12.10) Use foldRight instead of :\

Inherited from HasForeachEntry[A, B]

Inherited from CustomParallelizable[(A, B), ParHashMap[A, B]]

Inherited from Serializable

Inherited from java.io.Serializable

Inherited from AbstractMap[A, B]

Inherited from Map[A, B]

Inherited from MapLike[A, B, HashMap[A, B]]

Inherited from Iterable[(A, B)]

Packages

Package structure

Automatic imports

Guide

Using Collections

Creating Collections

Converting to and from Java Collections

HashMap 

Companion object HashMap

sealed class HashMap[A, +B] extends AbstractMap[A, B] with Map[A, B] with MapLike[A, B, HashMap[A, B]] with Serializable with CustomParallelizable[(A, B), ParHashMap[A, B]] with HasForeachEntry[A, B]

Instance Constructors

Type Members

Value Members

def ++:[C >: (A, B), That](that: TraversableOnce[C])(implicit bf: CanBuildFrom[HashMap[A, B], C, That]): That

def -(key: A): HashMap[A, B]

def collect[B, That](pf: PartialFunction[(A, B), B])(implicit bf: CanBuildFrom[HashMap[A, B], B, That]): That

def copyToArray[B >: (A, B)](xs: Array[B], start: Int, len: Int): Unit

def copyToArray[B >: (A, B)](xs: Array[B]): Unit

def copyToArray[B >: (A, B)](xs: Array[B], start: Int): Unit

def flatMap[B, That](f: ((A, B)) ⇒ GenTraversableOnce[B])(implicit bf: CanBuildFrom[HashMap[A, B], B, That]): That

def flatten[B](implicit asTraversable: ((A, B)) ⇒ GenTraversableOnce[B]): Iterable[B]

def foreach[U](f: ((A, B)) ⇒ U): Unit

def getOrElse[V1 >: B](key: A, default: ⇒ V1): V1

def map[B, That](f: ((A, B)) ⇒ B)(implicit bf: CanBuildFrom[HashMap[A, B], B, That]): That

def max[B >: (A, B)](implicit cmp: Ordering[B]): (A, B)

def maxBy[B](f: ((A, B)) ⇒ B)(implicit cmp: Ordering[B]): (A, B)

def min[B >: (A, B)](implicit cmp: Ordering[B]): (A, B)

def minBy[B](f: ((A, B)) ⇒ B)(implicit cmp: Ordering[B]): (A, B)

def product[B >: (A, B)](implicit num: Numeric[B]): B

def sameElements[B >: (A, B)](that: GenIterable[B]): Boolean

def sum[B >: (A, B)](implicit num: Numeric[B]): B

def to[Col[_]](implicit cbf: CanBuildFrom[Nothing, (A, B), Col[(A, B)]]): Col[(A, B)]

def toArray[B >: (A, B)](implicit arg0: ClassTag[B]): Array[B]

def zip[A1 >: (A, B), B, That](that: GenIterable[B])(implicit bf: CanBuildFrom[HashMap[A, B], (A1, B), That]): That

def zipAll[B, A1 >: (A, B), That](that: GenIterable[B], thisElem: A1, thatElem: B)(implicit bf: CanBuildFrom[HashMap[A, B], (A1, B), That]): That

def zipWithIndex[A1 >: (A, B), That](implicit bf: CanBuildFrom[HashMap[A, B], (A1, Int), That]): That

Shadowed Implicit Value Members

Deprecated Value Members

Inherited from HasForeachEntry[A, B]

Inherited from CustomParallelizable[(A, B), ParHashMap[A, B]]

Inherited from Serializable

Inherited from java.io.Serializable

Inherited from AbstractMap[A, B]

Inherited from Map[A, B]

Inherited from MapLike[A, B, HashMap[A, B]]

Inherited from Iterable[(A, B)]

Inherited from Traversable[(A, B)]

Inherited from Immutable

Inherited from collection.AbstractMap[A, B]

Inherited from collection.Map[A, B]

Inherited from collection.MapLike[A, B, HashMap[A, B]]

Inherited from Subtractable[A, HashMap[A, B]]

Inherited from PartialFunction[A, B]

Inherited from (A) ⇒ B

Inherited from GenMap[A, B]

Inherited from GenMapLike[A, B, HashMap[A, B]]

Inherited from AbstractIterable[(A, B)]

Inherited from collection.Iterable[(A, B)]

Inherited from IterableLike[(A, B), HashMap[A, B]]

Inherited from Equals

Inherited from GenIterable[(A, B)]

Inherited from GenIterableLike[(A, B), HashMap[A, B]]

Inherited from AbstractTraversable[(A, B)]

Inherited from collection.Traversable[(A, B)]

Inherited from GenTraversable[(A, B)]

Inherited from GenericTraversableTemplate[(A, B), Iterable]

Inherited from TraversableLike[(A, B), HashMap[A, B]]

Inherited from GenTraversableLike[(A, B), HashMap[A, B]]

Inherited from Parallelizable[(A, B), ParHashMap[A, B]]

Inherited from TraversableOnce[(A, B)]

Inherited from GenTraversableOnce[(A, B)]

Inherited from FilterMonadic[(A, B), HashMap[A, B]]

Inherited from HasNewBuilder[(A, B), HashMap[A, B]]

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion CollectionsHaveToParArray from HashMap[A, B] to CollectionsHaveToParArray[HashMap[A, B], T]

Inherited by implicit conversion MonadOps from HashMap[A, B] to MonadOps[(A, B)]

Inherited by implicit conversion any2stringadd from HashMap[A, B] to any2stringadd[HashMap[A, B]]

Inherited by implicit conversion StringFormat from HashMap[A, B] to StringFormat[HashMap[A, B]]

Inherited by implicit conversion Ensuring from HashMap[A, B] to Ensuring[HashMap[A, B]]

HashMap