trait Map[K, V] extends Iterable[(K, V)] with collection.Map[K, V] with MapOps[K, V, Map, Map[K, V]] with Growable[(K, V)] with Shrinkable[K]
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- By Inheritance
- Map
- MapOps
- Shrinkable
- Growable
- Clearable
- Cloneable
- Cloneable
- Cloneable
- Map
- Equals
- MapOps
- PartialFunction
- Function1
- Iterable
- IterableOps
- Iterable
- IterableOps
- IterableOnceOps
- IterableOnce
- AnyRef
- Any
- by iterableOnceExtensionMethods
- by toLazyZipOps
- by toLazyZipOps
- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
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Type Members
-
class
WithFilter extends collection.WithFilter[A, CC]
A template trait that contains just the
map
,flatMap
,foreach
andwithFilter
methods of traitIterable
.A template trait that contains just the
map
,flatMap
,foreach
andwithFilter
methods of traitIterable
.- Definition Classes
- IterableOps
-
trait
GenKeySet extends Serializable
A generic trait that is reused by keyset implementations
A generic trait that is reused by keyset implementations
- Attributes
- protected
- Definition Classes
- MapOps
-
class
KeySet extends Set[K] with GenKeySet
The implementation class of the set returned by
keySet
.The implementation class of the set returned by
keySet
.- Attributes
- protected
- Definition Classes
- MapOps
- Annotations
- @SerialVersionUID()
-
class
MapWithFilter extends WithFilter
Specializes
WithFilter
for Map collection typesSpecializes
WithFilter
for Map collection types- Definition Classes
- MapOps
-
type
IterableCC[X] = Iterable[X]
- Attributes
- protected[this]
- Definition Classes
- IterableOps
-
type
MapCC[K, V] = Map[K, V]
- Attributes
- protected[this]
- Definition Classes
- MapOps
Abstract Value Members
-
abstract
def
addOne(elem: (K, V)): Map.this.type
Adds a single element to this growable collection.
Adds a single element to this growable collection.
- elem
the element to add.
- returns
the growable collection itself
- Definition Classes
- Growable
-
abstract
def
clear(): Unit
Clears the collection's contents.
Clears the collection's contents. After this operation, the collection is empty.
- Definition Classes
- Clearable
-
abstract
def
get(key: K): Option[V]
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, orNone
if none exists.
- Definition Classes
- MapOps
-
abstract
def
iterator(): Iterator[(K, V)]
Iterator can be used only once
Iterator can be used only once
- Definition Classes
- IterableOnce
-
abstract
def
subtractOne(elem: K): Map.this.type
Removes a single element from this shrinkable collection.
Removes a single element from this shrinkable collection.
- elem
the element to remove.
- returns
the shrinkable collection itself
- Definition Classes
- Shrinkable
Concrete Value Members
-
final
def
!=(arg0: Any): Boolean
Test two objects for inequality.
Test two objects for inequality.
- returns
true
if !(this == that), false otherwise.
- Definition Classes
- AnyRef → Any
-
final
def
##(): Int
Equivalent to
x.hashCode
except for boxed numeric types andnull
.Equivalent to
x.hashCode
except for boxed numeric types andnull
. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. Fornull
returns a hashcode wherenull.hashCode
throws aNullPointerException
.- returns
a hash value consistent with ==
- Definition Classes
- AnyRef → Any
-
def
++[V2 >: V](xs: collection.Iterable[(K, V2)]): Map[K, V2]
Alias for
concat
Alias for
concat
- Definition Classes
- MapOps
-
final
def
++[B >: (K, V)](suffix: collection.Iterable[B]): Iterable[B]
Alias for
concat
Alias for
concat
- Definition Classes
- IterableOps
- Annotations
- @inline()
-
final
def
++=(xs: IterableOnce[(K, V)]): Map.this.type
Alias for
addAll
-
final
def
+=(elem1: (K, V), elem2: (K, V), elems: (K, V)*): Map.this.type
Adds two or more elements to this growable collection.
-
final
def
+=(elem: (K, V)): Map.this.type
Alias for
addOne
-
final
def
--=(xs: IterableOnce[K]): Map.this.type
Alias for
subtractAll
Alias for
subtractAll
- Definition Classes
- Shrinkable
- Annotations
- @inline()
-
def
-=(elem1: K, elem2: K, elems: K*): Map.this.type
Removes two or more elements from this shrinkable collection.
Removes two or more elements from this shrinkable collection.
- elem1
the first element to remove.
- elem2
the second element to remove.
- elems
the remaining elements to remove.
- returns
the shrinkable collection itself
- Definition Classes
- Shrinkable
-
final
def
-=(elem: K): Map.this.type
Alias for
subtractOne
Alias for
subtractOne
- Definition Classes
- Shrinkable
- Annotations
- @inline()
-
def
->[B](y: B): (Map[K, V], B)
- Implicit
- This member is added by an implicit conversion from Map[K, V] to ArrowAssoc[Map[K, V]] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @inline()
-
final
def
==(arg0: Any): Boolean
The expression
x == that
is equivalent toif (x eq null) that eq null else x.equals(that)
.The expression
x == that
is equivalent toif (x eq null) that eq null else x.equals(that)
.- returns
true
if the receiver object is equivalent to the argument;false
otherwise.
- Definition Classes
- AnyRef → Any
-
def
addAll(xs: IterableOnce[(K, V)]): Map.this.type
Adds all elements produced by a TraversableOnce to this growable collection.
Adds all elements produced by a TraversableOnce to this growable collection.
- xs
the TraversableOnce producing the elements to add.
- returns
the growable collection itself.
- Definition Classes
- Growable
-
def
addString(b: StringBuilder): StringBuilder
Appends all elements of this $coll to a string builder.
Appends all elements of this $coll to a string builder. The written text consists of the string representations (w.r.t. the method
toString
) of all elements of this $coll without any separator string.Example:
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> val h = a.addString(b) h: StringBuilder = 1234
- b
the string builder to which elements are appended.
- returns
the string builder
b
to which elements were appended.
- Definition Classes
- IterableOnceOps
-
def
addString(b: StringBuilder, sep: String): StringBuilder
Appends all elements of this $coll to a string builder using a separator string.
Appends all elements of this $coll 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 $coll, separated by the stringsep
.Example:
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> a.addString(b, ", ") res0: StringBuilder = 1, 2, 3, 4
- b
the string builder to which elements are appended.
- sep
the separator string.
- returns
the string builder
b
to which elements were appended.
- Definition Classes
- IterableOnceOps
-
def
addString(b: StringBuilder, start: String, sep: String, end: String): b.type
Appends all elements of this $coll to a string builder using start, end, and separator strings.
Appends all elements of this $coll to a string builder using start, end, and separator strings. The written text begins with the string
start
and ends with the stringend
. Inside, the string representations (w.r.t. the methodtoString
) of all elements of this $coll are separated by the stringsep
.Example:
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> a.addString(b , "List(" , ", " , ")") res5: StringBuilder = List(1, 2, 3, 4)
- b
the string builder to which elements 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
- IterableOnceOps
-
def
andThen[C](k: (V) ⇒ C): PartialFunction[K, C]
Composes this partial function with a transformation function that gets applied to results of this partial function.
Composes this partial function with a transformation function that gets applied to results of this partial function.
- 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
tok(this(x))
.
- Definition Classes
- PartialFunction → Function1
-
def
apply(key: K): V
Retrieves the value which is associated with the given key.
Retrieves the value which is associated with the given key. This method invokes the
default
method of the map if there is no mapping from the given key to a value. Unless overridden, thedefault
method throws aNoSuchElementException
.- key
the key
- returns
the value associated with the given key, or the result of the map's
default
method, if none exists.
-
def
applyOrElse[K1 <: K, V1 >: V](x: K1, default: (K1) ⇒ V1): V1
Applies this partial function to the given argument when it is contained in the function domain.
Applies this partial function to the given argument when it is contained in the function domain. Applies fallback function where this partial function is not defined.
Note that expression
pf.applyOrElse(x, default)
is equivalent toif(pf isDefinedAt x) pf(x) else default(x)
except that
applyOrElse
method can be implemented more efficiently. For all partial function literals the compiler generates anapplyOrElse
implementation which avoids double evaluation of pattern matchers and guards. This makesapplyOrElse
the basis for the efficient implementation for many operations and scenarios, such as:- combining partial functions into
orElse
/andThen
chains does not lead to excessiveapply
/isDefinedAt
evaluation lift
andunlift
do not evaluate source functions twice on each invocationrunWith
allows efficient imperative-style combining of partial functions with conditionally applied actions
For non-literal partial function classes with nontrivial
isDefinedAt
method it is recommended to overrideapplyOrElse
with custom implementation that avoids doubleisDefinedAt
evaluation. This may result in better performance and more predictable behavior w.r.t. side effects.- x
the function argument
- default
the fallback function
- returns
the result of this function or fallback function application.
- Definition Classes
- MapOps → PartialFunction
- Since
2.10
- combining partial functions into
-
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 aClassCastException
at runtime, while the expressionList(1).asInstanceOf[List[String]]
will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.- returns
the receiver object.
- Definition Classes
- Any
- Exceptions thrown
ClassCastException
if the receiver object is not an instance of the erasure of typeT0
.
-
def
canEqual(that: Any): Boolean
A method that should be called from every well-designed equals method that is open to be overridden in a subclass.
A method that should be called from every well-designed equals method that is open to be overridden in a subclass. See Programming in Scala, Chapter 28 for discussion and design.
- that
the value being probed for possible equality
- returns
true if this instance can possibly equal
that
, otherwise false
-
def
className: String
Defines the prefix of this object's
toString
representation.Defines the prefix of this object's
toString
representation.It is recommended to return the name of the concrete collection type, but not implementation subclasses. For example, for
ListMap
this method should return"ListMap"
, not"Map"
(the supertype) or"Node"
(an implementation subclass).It is recommended to overwrite this method even if the default implementation returns the correct name, to avoid the implementation using reflection.
- returns
a string representation which starts the result of
toString
applied to this iterable collection. By default the string prefix is the simple name of the collection class iterable collection.
- Definition Classes
- IterableOps
-
def
clone(): Map[K, V]
Create a copy of the receiver object.
-
def
coll: Map.this.type
- returns
This collection as a
C
.
- Attributes
- protected[this]
- Definition Classes
- Iterable → IterableOps
-
def
collect[K2, V2](pf: PartialFunction[(K, V), (K2, V2)]): Map[K2, V2]
Builds a new collection by applying a partial function to all elements of this map on which the function is defined.
Builds a new collection by applying a partial function to all elements of this map on which the function is defined.
- K2
the key type of the returned map.
- V2
the value type of the returned map.
- pf
the partial function which filters and maps the map.
- returns
a new 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
- MapOps
-
def
collect[B](pf: PartialFunction[(K, V), B]): Iterable[B]
Builds a new iterable collection by applying a partial function to all elements of this iterable collection on which the function is defined.
Builds a new iterable collection by applying a partial function to all elements of this iterable collection on which the function is defined.
- B
the element type of the returned iterable collection.
- pf
the partial function which filters and maps the iterable collection.
- returns
a new iterable collection 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
- IterableOps → IterableOnceOps
- Note
Reuse: $consumesAndProducesIterator
-
def
collectFirst[B](pf: PartialFunction[(K, V), B]): Option[B]
Finds the first element of the $coll for which the given partial function is defined, and applies the partial function to it.
Finds the first element of the $coll for which the given partial function is defined, and applies the partial function to it.
$mayNotTerminateInf $orderDependent
- pf
the partial function
- returns
an option value containing pf applied to the first value for which it is defined, or
None
if none exists.
- Definition Classes
- IterableOnceOps
Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)
Example: -
def
compose[A](g: (A) ⇒ K): (A) ⇒ V
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 thatf(x) == apply(g(x))
- Definition Classes
- Function1
- Annotations
- @unspecialized()
-
def
concat[V2 >: V](suffix: collection.Iterable[(K, V2)]): Map[K, V2]
Returns a new map containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new map containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the map is the most specific superclass encompassing the element types of the two operands.
- suffix
the traversable to append.
- returns
a new map which contains all elements of this map followed by all elements of
suffix
.
- Definition Classes
- MapOps
-
def
concat[B >: (K, V)](suffix: collection.Iterable[B]): Iterable[B]
Returns a new iterable collection containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new iterable collection containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the iterable collection is the most specific superclass encompassing the element types of the two operands.
- B
the element type of the returned collection.
- suffix
the traversable to append.
- returns
a new iterable collection which contains all elements of this iterable collection followed by all elements of
suffix
.
- Definition Classes
- IterableOps
-
def
contains(key: K): Boolean
Tests whether this map contains a binding for a key.
Tests whether this map contains a binding for a key.
- key
the key
- returns
true
if there is a binding forkey
in this map,false
otherwise.
- Definition Classes
- MapOps
-
def
copyToArray(xs: Array[(K, V)], start: Int, len: Int): Unit
[use case] Note: will not terminate for infinite-sized collections.
[use case]Note: will not terminate for infinite-sized collections.
- xs
the array to fill.
- start
the starting index.
- len
the maximal number of elements to copy.
- Definition Classes
- IterableOnceOps
-
def
copyToArray(xs: Array[(K, V)], start: Int): Unit
[use case] Note: will not terminate for infinite-sized collections.
[use case]Note: will not terminate for infinite-sized collections.
- xs
the array to fill.
- start
the starting index.
- Definition Classes
- IterableOnceOps
-
def
count(p: ((K, V)) ⇒ Boolean): Int
Counts the number of elements in the $coll which satisfy a predicate.
Counts the number of elements in the $coll which satisfy a predicate.
- p
the predicate used to test elements.
- returns
the number of elements satisfying the predicate
p
.
- Definition Classes
- IterableOnceOps
-
def
default(key: K): V
Defines the default value computation for the map, returned when a key is not found 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.
-
def
drop(n: Int): Map[K, V]
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 thann
elements. Ifn
is negative, don't drop any elements.
- Definition Classes
- IterableOps → IterableOnceOps
- Note
Reuse: $consumesAndProducesIterator
-
def
dropRight(n: Int): Map[K, V]
The rest of the collection without its
n
last elements.The rest of the collection without its
n
last elements. For linear, immutable collections this should avoid making a copy.- Definition Classes
- IterableOps
-
def
dropWhile(p: ((K, V)) ⇒ Boolean): Map[K, V]
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.
- p
The predicate used to test elements.
- returns
the longest suffix of this iterable collection whose first element does not satisfy the predicate
p
.
- Definition Classes
- IterableOps → IterableOnceOps
- Note
Reuse: $consumesAndProducesIterator
-
def
empty: MapCC[K, V]
The empty map of the same type as this map
-
def
ensuring(cond: (Map[K, V]) ⇒ Boolean, msg: ⇒ Any): Map[K, V]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to Ensuring[Map[K, V]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: (Map[K, V]) ⇒ Boolean): Map[K, V]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to Ensuring[Map[K, V]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: Boolean, msg: ⇒ Any): Map[K, V]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to Ensuring[Map[K, V]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: Boolean): Map[K, V]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to Ensuring[Map[K, V]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
final
def
eq(arg0: AnyRef): Boolean
Tests whether the argument (
that
) is a reference to the receiver object (this
).Tests whether the argument (
that
) is a reference to the receiver object (this
).The
eq
method implements an equivalence relation on non-null instances ofAnyRef
, and has three additional properties:- It is consistent: for any non-null instances
x
andy
of typeAnyRef
, multiple invocations ofx.eq(y)
consistently returnstrue
or consistently returnsfalse
. - For any non-null instance
x
of typeAnyRef
,x.eq(null)
andnull.eq(x)
returnsfalse
. null.eq(null)
returnstrue
.
When overriding the
equals
orhashCode
methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2
), they should be equal to each other (o1 == o2
) and they should hash to the same value (o1.hashCode == o2.hashCode
).- returns
true
if the argument is a reference to the receiver object;false
otherwise.
- Definition Classes
- AnyRef
- It is consistent: for any non-null instances
-
def
equals(o: Any): Boolean
The universal equality method defined in
AnyRef
. -
def
exists(p: ((K, V)) ⇒ Boolean): Boolean
Tests whether a predicate holds for at least one element of this $coll.
Tests whether a predicate holds for at least one element of this $coll.
$mayNotTerminateInf
- p
the predicate used to test elements.
- returns
true
if the given predicatep
is satisfied by at least one element of this $coll, otherwisefalse
- Definition Classes
- IterableOnceOps
-
def
filter(pred: ((K, V)) ⇒ Boolean): Map[K, V]
Selects all elements of this iterable collection which satisfy a predicate.
Selects all elements of this iterable collection which satisfy a predicate.
- returns
a new iterator consisting of all elements of this iterable collection that satisfy the given predicate
p
. The order of the elements is preserved.
- Definition Classes
- IterableOps → IterableOnceOps
-
def
filterInPlace(p: ((K, V)) ⇒ Boolean): Map.this.type
- Definition Classes
- MapOps
-
def
filterKeys(p: (K) ⇒ Boolean): MapView[K, V]
Filters this map by retaining only keys satisfying a predicate.
Filters this map by retaining only keys satisfying a predicate.
- p
the predicate used to test keys
- returns
an immutable map consisting only of those key value pairs of this map where the key satisfies the predicate
p
. The resulting map wraps the original map without copying any elements.
- Definition Classes
- MapOps
-
def
filterNot(pred: ((K, V)) ⇒ Boolean): Map[K, V]
Selects all elements of this iterable collection which do not satisfy a predicate.
Selects all elements of this iterable collection which do not satisfy a predicate.
- pred
the predicate used to test elements.
- returns
a new iterable collection consisting of all elements of this iterable collection that do not satisfy the given predicate
pred
. Their order may not be preserved.
- Definition Classes
- IterableOps → IterableOnceOps
-
def
finalize(): Unit
Called by the garbage collector on the receiver object when there are no more references to the object.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the
finalize
method is invoked, as well as the interaction betweenfinalize
and non-local returns and exceptions, are all platform dependent. -
def
find(p: ((K, V)) ⇒ Boolean): Option[(K, V)]
Finds the first element of the $coll satisfying a predicate, if any.
Finds the first element of the $coll satisfying a predicate, if any.
$mayNotTerminateInf $orderDependent
- p
the predicate used to test elements.
- returns
an option value containing the first element in the $coll that satisfies
p
, orNone
if none exists.
- Definition Classes
- IterableOnceOps
-
def
flatMap[K2, V2](f: ((K, V)) ⇒ IterableOnce[(K2, V2)]): Map[K2, V2]
Builds a new map by applying a function to all elements of this map and using the elements of the resulting collections.
Builds a new map by applying a function to all elements of this map and using the elements of the resulting collections.
- f
the function to apply to each element.
- returns
a new map resulting from applying the given collection-valued function
f
to each element of this map and concatenating the results.
- Definition Classes
- MapOps
-
def
flatMap[B](f: ((K, V)) ⇒ IterableOnce[B]): Iterable[B]
Builds a new iterable collection by applying a function to all elements of this iterable collection and using the elements of the resulting collections.
Builds a new iterable collection by applying a function to all elements of this iterable collection 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 iterable collection. 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 iterable collection resulting from applying the given collection-valued function
f
to each element of this iterable collection and concatenating the results.
- Definition Classes
- IterableOps → IterableOnceOps
- Note
Reuse: $consumesAndProducesIterator
-
def
flatMapInPlace(f: ((K, V)) ⇒ IterableOnce[(K, V)]): Map.this.type
- Definition Classes
- MapOps
-
def
flatten[B](implicit asIterable: ((K, V)) ⇒ IterableOnce[B]): Iterable[B]
Converts this iterable collection of traversable collections into a iterable collection formed by the elements of these traversable collections.
Converts this iterable collection of traversable collections into a iterable collection formed by the elements of these traversable collections.
The resulting collection's type will be guided by the type of iterable collection. 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.
- asIterable
an implicit conversion which asserts that the element type of this iterable collection is a
GenTraversable
.- returns
a new iterable collection resulting from concatenating all element iterable collections.
- Definition Classes
- IterableOps → IterableOnceOps
- Note
Reuse: $consumesAndProducesIterator
-
def
foldLeft[B](z: B)(op: (B, (K, V)) ⇒ B): B
Applies a binary operator to a start value and all elements of this $coll, going left to right.
Applies a binary operator to a start value and all elements of this $coll, going left to right.
$willNotTerminateInf $orderDependentFold
- 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 $coll, going left to right with the start valuez
on the left:op(...op(z, x_1), x_2, ..., x_n)
where
x1, ..., xn
are the elements of this $coll. Returnsz
if this $coll is empty.
- Definition Classes
- IterableOnceOps
-
def
foldRight[B](z: B)(op: ((K, V), B) ⇒ B): B
Applies a binary operator to all elements of this $coll and a start value, going right to left.
Applies a binary operator to all elements of this $coll and a start value, going right to left.
$willNotTerminateInf $orderDependentFold
- 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 $coll, going right to left with the start valuez
on the right:op(x_1, op(x_2, ... op(x_n, z)...))
where
x1, ..., xn
are the elements of this $coll. Returnsz
if this $coll is empty.
- Definition Classes
- IterableOnceOps
-
def
forall(p: ((K, V)) ⇒ Boolean): Boolean
Tests whether a predicate holds for all elements of this $coll.
Tests whether a predicate holds for all elements of this $coll.
$mayNotTerminateInf
- p
the predicate used to test elements.
- returns
true
if this $coll is empty or the given predicatep
holds for all elements of this $coll, otherwisefalse
.
- Definition Classes
- IterableOnceOps
-
def
foreach[U](f: ((K, V)) ⇒ U): Unit
Apply
f
to each element for its side effects Note: [U] parameter needed to help scalac's type inference.Apply
f
to each element for its side effects Note: [U] parameter needed to help scalac's type inference.- Definition Classes
- IterableOnceOps
-
def
formatted(fmtstr: String): String
Returns string formatted according to given
format
string.Returns string formatted according to given
format
string. Format strings are as forString.format
(@see java.lang.String.format).- Implicit
- This member is added by an implicit conversion from Map[K, V] to StringFormat[Map[K, V]] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @inline()
-
final
def
fromIterable[E](it: collection.Iterable[E]): Iterable[E]
Similar to
fromSpecificIterable
, but for a (possibly) different type of element.Similar to
fromSpecificIterable
, but for a (possibly) different type of element. Note that the return type is nowCC[E]
.- Attributes
- protected[this]
- Definition Classes
- IterableOps
- Annotations
- @inline()
-
def
fromSpecificIterable(coll: collection.Iterable[(K, V)]): MapCC[K, V]
Defines how to turn a given
Iterable[A]
into a collection of typeC
.Defines how to turn a given
Iterable[A]
into a collection of typeC
.This process can be done in a strict way or a non-strict way (ie. without evaluating the elements of the resulting collections). In other words, this methods defines the evaluation model of the collection.
- Attributes
- protected[this]
- Definition Classes
- Map → Iterable → IterableOps
-
final
def
getClass(): Class[_]
Returns the runtime class representation of the object.
-
def
getOrElse(key: K, default: ⇒ V): V
[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 thedefault
computation.
- Definition Classes
- MapOps
Full Signaturedef getOrElse[V1 >: V](key: K, default: ⇒ V1): V1
-
def
getOrElseUpdate(key: K, op: ⇒ V): V
If given key is already in this map, returns associated value.
If given key is already in this map, returns associated value.
Otherwise, computes value from given expression
op
, stores with key in map and returns that value.Concurrent map implementations may evaluate the expression
op
multiple times, or may evaluateop
without inserting the result.- key
the key to test
- op
the computation yielding the value to associate with
key
, ifkey
is previously unbound.- returns
the value associated with key (either previously or as a result of executing the method).
- Definition Classes
- MapOps
-
def
groupBy[K](f: ((K, V)) ⇒ K): immutable.Map[K, Map[K, V]]
Partitions this iterable collection into a map of iterable collections according to some discriminator function.
Partitions this iterable collection into a map of iterable collections according to some discriminator function.
Note: When applied to a view or a lazy collection it will always force the elements.
- K
the type of keys returned by the discriminator function.
- f
the discriminator function.
- returns
A map from keys to iterable 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 iterable collection of those elementsx
for whichf(x)
equalsk
.
- Definition Classes
- IterableOps
-
def
groupMap[K, B](key: ((K, V)) ⇒ K)(f: ((K, V)) ⇒ B): immutable.Map[K, Iterable[B]]
Partitions this iterable collection into a map of iterable collections according to a discriminator function
key
.Partitions this iterable collection into a map of iterable collections according to a discriminator function
key
. Each element in a group is transformed into a value of typeB
using thevalue
function.It is equivalent to
groupBy(key).mapValues(_.map(f))
, but more efficient.case class User(name: String, age: Int) def namesByAge(users: Seq[User]): Map[Int, Seq[String]] = users.groupMap(_.age)(_.name)
- K
the type of keys returned by the discriminator function
- B
the type of values returned by the transformation function
- key
the discriminator function
- f
the element transformation function
- Definition Classes
- IterableOps
-
def
groupMapReduce[K, B](key: ((K, V)) ⇒ K)(f: ((K, V)) ⇒ B)(reduce: (B, B) ⇒ B): immutable.Map[K, B]
Partitions this iterable collection into a map according to a discriminator function
key
.Partitions this iterable collection into a map according to a discriminator function
key
. All the values that have the same discriminator are then transformed by thevalue
function and then reduced into a single value with thereduce
function.It is equivalent to
groupBy(key).mapValues(_.map(f).reduce(reduce))
, but more efficient.def occurrences[A](as: Seq[A]): Map[A, Int] = as.groupMapReduce(identity)(_ => 1)(_ + _)
- Definition Classes
- IterableOps
-
def
grouped(size: Int): Iterator[Map[K, V]]
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 sizesize
if the elements don't divide evenly.
- Definition Classes
- IterableOps
- See also
scala.collection.Iterator, method
grouped
-
def
hashCode(): Int
The hashCode method for reference types.
-
def
head: (K, V)
Selects the first element of this 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
- IterableOps
- Exceptions thrown
NoSuchElementException
if the iterable collection is empty.
-
def
headOption: Option[(K, V)]
Optionally selects the first element.
Optionally selects the first element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- returns
the first element of this iterable collection if it is nonempty,
None
if it is empty.
- Definition Classes
- IterableOps
-
def
init: Map[K, V]
The initial part of the collection without its last element.
The initial part of the collection without its last element.
- Definition Classes
- IterableOps
-
def
inits: Iterator[Map[K, V]]
Iterates over the inits of this iterable collection.
Iterates over the inits of this iterable collection. The first value will be this iterable collection and the final one will be an empty iterable collection, with the intervening values the results of successive applications of
init
.- returns
an iterator over all the inits of this iterable collection
- Definition Classes
- IterableOps
List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)
Example: -
def
isDefinedAt(key: K): Boolean
Tests whether this map contains a binding for a key.
Tests whether this map contains a binding for a key. This method, which implements an abstract method of trait
PartialFunction
, is equivalent tocontains
.- key
the key
- returns
true
if there is a binding forkey
in this map,false
otherwise.
- Definition Classes
- MapOps → PartialFunction
-
def
isEmpty: Boolean
Tests whether the $coll is empty.
Tests whether the $coll is empty.
Note: Implementations in subclasses that are not repeatedly traversable must take care not to consume any elements when
isEmpty
is called.- returns
true
if the $coll contains no elements,false
otherwise.
- Definition Classes
- IterableOnceOps
-
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 returnfalse
, while the expressionList(1).isInstanceOf[List[String]]
will returntrue
. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.- returns
true
if the receiver object is an instance of erasure of typeT0
;false
otherwise.
- Definition Classes
- Any
-
def
iterableFactory: IterableFactory[IterableCC]
- returns
The companion object of this mutable collection, providing various factory methods.
- Definition Classes
- Iterable → Iterable → IterableOps
-
def
keySet: collection.Set[K]
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
- MapOps
-
def
keys: collection.Iterable[K]
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
- MapOps
-
def
keysIterator(): Iterator[K]
Creates an iterator for all keys.
-
def
knownSize: Int
The number of elements in this $coll, if it can be cheaply computed, -1 otherwise.
The number of elements in this $coll, if it can be cheaply computed, -1 otherwise. Cheaply usually means: Not requiring a collection traversal.
- Definition Classes
- IterableOnceOps
-
def
last: (K, V)
Selects the last element.
Selects the last element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- returns
The last element of this iterable collection.
- Definition Classes
- IterableOps
- Exceptions thrown
NoSuchElementException
If the iterable collection is empty.
-
def
lastOption: Option[(K, V)]
Optionally selects the last element.
Optionally selects the last element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- returns
the last element of this iterable collection$ if it is nonempty,
None
if it is empty.
- Definition Classes
- IterableOps
-
def
lift: (K) ⇒ Option[V]
Turns this partial function into a plain function returning an
Option
result.Turns this partial function into a plain function returning an
Option
result.- returns
a function that takes an argument
x
toSome(this(x))
ifthis
is defined forx
, and toNone
otherwise.
- Definition Classes
- PartialFunction
- See also
Function.unlift
-
def
map[K2, V2](f: ((K, V)) ⇒ (K2, V2)): Map[K2, V2]
Builds a new map by applying a function to all elements of this map.
Builds a new map by applying a function to all elements of this map.
- f
the function to apply to each element.
- returns
a new map resulting from applying the given function
f
to each element of this map and collecting the results.
- Definition Classes
- MapOps
-
def
map[B](f: ((K, V)) ⇒ B): Iterable[B]
Builds a new iterable collection by applying a function to all elements of this iterable collection.
Builds a new iterable collection by applying a function to all elements of this iterable collection.
- B
the element type of the returned iterable collection.
- f
the function to apply to each element.
- returns
a new iterable collection resulting from applying the given function
f
to each element of this iterable collection and collecting the results.
- Definition Classes
- IterableOps → IterableOnceOps
- Note
Reuse: $consumesAndProducesIterator
- def mapFactory: MapFactory[MapCC]
-
final
def
mapFromIterable[K2, V2](it: collection.Iterable[(K2, V2)]): Map[K2, V2]
Similar to
fromIterable
, but returns a Map collection type. -
def
mapInPlace(f: ((K, V)) ⇒ (K, V)): Map.this.type
Modifies this mutable map by applying a function to all elements of this mutable map.
Modifies this mutable map by applying a function to all elements of this mutable map.
- f
the function to apply to each element.
- returns
this mutable map modified by replacing all elements with the result of applying the given function
f
to each element of this mutable map.
- Definition Classes
- MapOps → IterableOps
-
def
mapValues[W](f: (V) ⇒ W): MapView[K, W]
Transforms this map by applying a function to every retrieved value.
Transforms this map by applying a function to every retrieved value.
- f
the function used to transform values of this map.
- returns
a map view which maps every key of this map to
f(this(key))
. The resulting map wraps the original map without copying any elements.
- Definition Classes
- MapOps
-
def
max: (K, V)
[use case] Finds the largest element.
[use case]Finds the largest element.
- returns
the largest element of this mutable map.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this mutable map is empty.
Full Signaturedef max[B >: (K, V)](implicit ord: math.Ordering[B]): (K, V)
-
def
maxBy[B](f: ((K, V)) ⇒ B): (K, V)
[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 mutable map with the largest value measured by function f.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this mutable map is empty.
Full Signaturedef maxBy[B](f: ((K, V)) ⇒ B)(implicit cmp: math.Ordering[B]): (K, V)
-
def
min: (K, V)
[use case] Finds the smallest element.
[use case]Finds the smallest element.
- returns
the smallest element of this mutable map
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this mutable map is empty.
Full Signaturedef min[B >: (K, V)](implicit ord: math.Ordering[B]): (K, V)
-
def
minBy[B](f: ((K, V)) ⇒ B): (K, V)
[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 mutable map with the smallest value measured by function f.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this mutable map is empty.
Full Signaturedef minBy[B](f: ((K, V)) ⇒ B)(implicit cmp: math.Ordering[B]): (K, V)
-
def
mkString(start: String, sep: String, end: String): String
Displays all elements of this map in a string using start, end, and separator strings.
Displays all elements of this map 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 map. The resulting string begins with the string
start
and ends with the stringend
. Inside, the string representations (w.r.t. the methodtoString
) of all elements of this map are separated by the stringsep
.
- Definition Classes
- MapOps → IterableOnceOps
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
Example: -
def
mkString: String
Displays all elements of this $coll in a string.
Displays all elements of this $coll in a string.
- returns
a string representation of this $coll. In the resulting string the string representations (w.r.t. the method
toString
) of all elements of this $coll follow each other without any separator string.
- Definition Classes
- IterableOnceOps
-
def
mkString(sep: String): String
Displays all elements of this $coll in a string using a separator string.
Displays all elements of this $coll in a string using a separator string.
- sep
the separator string.
- returns
a string representation of this $coll. In the resulting string the string representations (w.r.t. the method
toString
) of all elements of this $coll are separated by the stringsep
.
- Definition Classes
- IterableOnceOps
List(1, 2, 3).mkString("|") = "1|2|3"
Example: -
final
def
ne(arg0: AnyRef): Boolean
Equivalent to
!(this eq that)
.Equivalent to
!(this eq that)
.- returns
true
if the argument is not a reference to the receiver object;false
otherwise.
- Definition Classes
- AnyRef
-
def
newSpecificBuilder(): Builder[(K, V), MapCC[K, V]]
- returns
a strict builder for the same collection type. Note that in the case of lazy collections (e.g. View or immutable.LazyList), it is possible to implement this method but the resulting
Builder
will break laziness. As a consequence, operations should preferably be implemented withfromSpecificIterable
instead of this method.
- Attributes
- protected[this]
- Definition Classes
- Map → Iterable → IterableOps
-
def
nonEmpty: Boolean
Tests whether the $coll is not empty.
Tests whether the $coll is not empty.
- returns
true
if the $coll contains at least one element,false
otherwise.
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecatedOverriding( message = ... , since = "2.13.0" )
-
final
def
notify(): Unit
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
- Definition Classes
- AnyRef
- Annotations
- @native()
- Note
not specified by SLS as a member of AnyRef
-
final
def
notifyAll(): Unit
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
- Definition Classes
- AnyRef
- Annotations
- @native()
- Note
not specified by SLS as a member of AnyRef
-
def
orElse[A1 <: K, B1 >: V](that: PartialFunction[A1, B1]): PartialFunction[A1, B1]
Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.
Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.
- A1
the argument type of the fallback function
- B1
the result type of the fallback function
- that
the fallback function
- returns
a partial function which has as domain the union of the domains of this partial function and
that
. The resulting partial function takesx
tothis(x)
wherethis
is defined, and tothat(x)
where it is not.
- Definition Classes
- PartialFunction
-
def
partition(p: ((K, V)) ⇒ Boolean): (Map[K, V], Map[K, V])
A pair of, first, all elements that satisfy prediacte
p
and, second, all elements that do not.A pair of, first, all elements that satisfy prediacte
p
and, second, all elements that do not. Interesting because it splits a collection in two.The default implementation provided here needs to traverse the collection twice. Strict collections have an overridden version of
partition
inBuildable
, which requires only a single traversal.- Definition Classes
- IterableOps
-
def
product: (K, V)
[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 mutable map of numbers of type
Int
. Instead ofInt
, any other typeT
with an implicitNumeric[T]
implementation can be used as element type of the mutable map and as result type ofproduct
. Examples of such types are:Long
,Float
,Double
,BigInt
.
- Definition Classes
- IterableOnceOps
Full Signaturedef product[B >: (K, V)](implicit num: math.Numeric[B]): B
-
def
put(key: K, value: V): Option[V]
Adds a new key/value pair to this map and optionally returns previously bound value.
Adds a new key/value pair to this map and optionally returns previously bound value. If the map already contains a mapping for the key, it will be overridden by the new value.
- key
the key to update
- value
the new value
- returns
an option value containing the value associated with the key before the
put
operation was executed, orNone
ifkey
was not defined in the map before.
- Definition Classes
- MapOps
-
def
reduce[B >: (K, V)](op: (B, B) ⇒ B): B
Reduces the elements of this $coll using the specified associative binary operator.
Reduces the elements of this $coll using the specified associative binary operator.
$undefinedorder
- B
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 $coll is nonempty.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this $coll is empty.
-
def
reduceLeft[B >: (K, V)](op: (B, (K, V)) ⇒ B): B
Applies a binary operator to all elements of this $coll, going left to right.
Applies a binary operator to all elements of this $coll, going left to right. $willNotTerminateInf $orderDependentFold
- B
the result type of the binary operator.
- op
the binary operator.
- returns
the result of inserting
op
between consecutive elements of this $coll, going left to right:op( op( ... op(x_1, x_2) ..., x_{n-1}), x_n)
where
x1, ..., xn
are the elements of this $coll.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this $coll is empty.
-
def
reduceLeftOption[B >: (K, V)](op: (B, (K, V)) ⇒ B): Option[B]
Optionally applies a binary operator to all elements of this $coll, going left to right.
Optionally applies a binary operator to all elements of this $coll, going left to right. $willNotTerminateInf $orderDependentFold
- B
the result type of the binary operator.
- op
the binary operator.
- returns
an option value containing the result of
reduceLeft(op)
if this $coll is nonempty,None
otherwise.
- Definition Classes
- IterableOnceOps
-
def
reduceOption[B >: (K, V)](op: (B, B) ⇒ B): Option[B]
Reduces the elements of this $coll, if any, using the specified associative binary operator.
Reduces the elements of this $coll, if any, using the specified associative binary operator.
$undefinedorder
- B
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, andNone
otherwise.
- Definition Classes
- IterableOnceOps
-
def
reduceRight[B >: (K, V)](op: ((K, V), B) ⇒ B): B
Applies a binary operator to all elements of this $coll, going right to left.
Applies a binary operator to all elements of this $coll, going right to left. $willNotTerminateInf $orderDependentFold
- B
the result type of the binary operator.
- op
the binary operator.
- returns
the result of inserting
op
between consecutive elements of this $coll, going right to left:op(x_1, op(x_2, ..., op(x_{n-1}, x_n)...))
where
x1, ..., xn
are the elements of this $coll.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this $coll is empty.
-
def
reduceRightOption[B >: (K, V)](op: ((K, V), B) ⇒ B): Option[B]
Optionally applies a binary operator to all elements of this $coll, going right to left.
Optionally applies a binary operator to all elements of this $coll, going right to left. $willNotTerminateInf $orderDependentFold
- B
the result type of the binary operator.
- op
the binary operator.
- returns
an option value containing the result of
reduceRight(op)
if this $coll is nonempty,None
otherwise.
- Definition Classes
- IterableOnceOps
-
def
remove(key: K): Option[V]
Removes a key from this map, returning the value associated previously with that key as an option.
Removes a key from this map, returning the value associated previously with that key as an option.
- key
the key to be removed
- returns
an option value containing the value associated previously with
key
, orNone
ifkey
was not defined in the map before.
- Definition Classes
- MapOps
-
def
reversed: collection.Iterable[(K, V)]
- Attributes
- protected[this]
- Definition Classes
- IterableOnceOps
-
def
runWith[U](action: (V) ⇒ U): (K) ⇒ Boolean
Composes this partial function with an action function which gets applied to results of this partial function.
Composes this partial function with an action function which gets applied to results of this partial function. The action function is invoked only for its side effects; its result is ignored.
Note that expression
pf.runWith(action)(x)
is equivalent toif(pf isDefinedAt x) { action(pf(x)); true } else false
except that
runWith
is implemented viaapplyOrElse
and thus potentially more efficient. UsingrunWith
avoids double evaluation of pattern matchers and guards for partial function literals.- action
the action function
- returns
a function which maps arguments
x
toisDefinedAt(x)
. The resulting function runsaction(this(x))
wherethis
is defined.
- Definition Classes
- PartialFunction
- Since
2.10
- See also
applyOrElse
.
-
def
scan[B >: (K, V)](z: B)(op: (B, B) ⇒ B): Iterable[B]
Computes a prefix scan of the elements of the collection.
Computes a prefix scan of the elements of the collection.
Note: The neutral element
z
may be applied more than once.- B
element type of the resulting collection
- z
neutral element for the operator
op
- op
the associative operator for the scan
- returns
a new iterable collection containing the prefix scan of the elements in this iterable collection
- Definition Classes
- IterableOps
-
def
scanLeft[B](z: B)(op: (B, (K, V)) ⇒ B): Iterable[B]
Produces a iterable collection containing cumulative results of applying the operator going left to right, including the initial value.
Produces a iterable collection containing cumulative results of applying the operator going left to right, including the initial value.
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
- z
the initial value
- op
the binary operator applied to the intermediate result and the element
- returns
collection with intermediate results
- Definition Classes
- IterableOps → IterableOnceOps
- Note
Reuse: $consumesAndProducesIterator
-
def
scanRight[B](z: B)(op: ((K, V), B) ⇒ B): Iterable[B]
Produces a collection containing cumulative results of applying the operator going right to left.
Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.
Note: 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
- z
the initial value
- op
the binary operator applied to the intermediate result and the element
- returns
collection with intermediate results
- Definition Classes
- IterableOps
-
def
size: Int
The size of this $coll.
The size of this $coll.
$willNotTerminateInf
- returns
the number of elements in this $coll.
- Definition Classes
- IterableOnceOps
-
def
slice(from: Int, until: Int): Map[K, V]
Selects an interval of elements.
Selects an interval of elements. The returned iterable 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.
- from
the lowest index to include from this iterable collection.
- until
the lowest index to EXCLUDE from this iterable collection.
- returns
a iterable collection containing the elements greater than or equal to index
from
extending up to (but not including) indexuntil
of this iterable collection.
- Definition Classes
- IterableOps → IterableOnceOps
- Note
Reuse: $consumesAndProducesIterator
-
def
sliding(size: Int, step: Int): Iterator[Map[K, V]]
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.)
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.)
- 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 thansize
elements remaining to be grouped.
- Definition Classes
- IterableOps
- See also
scala.collection.Iterator, method
sliding
-
def
sliding(size: Int): Iterator[Map[K, V]]
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in
grouped
.) 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 thansize
elements remaining to be grouped.
- Definition Classes
- IterableOps
- See also
scala.collection.Iterator, method
sliding
-
def
span(p: ((K, V)) ⇒ Boolean): (Map[K, V], Map[K, V])
Splits this iterable collection into a prefix/suffix pair according to a predicate.
Splits this iterable 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 predicatep
does not cause any side-effects.Note: might return different results for different runs, unless the underlying collection type is ordered.
- p
the test predicate
- returns
a pair consisting of the longest prefix of this iterable collection whose elements all satisfy
p
, and the rest of this iterable collection.
- Definition Classes
- IterableOps → IterableOnceOps
- Note
Reuse: $consumesOneAndProducesTwoIterators
-
def
splitAt(n: Int): (Map[K, V], Map[K, V])
Splits this iterable collection into two at a given position.
Splits this iterable 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 iterable collections consisting of the first
n
elements of this iterable collection, and the other elements.
- Definition Classes
- IterableOps
-
def
subtractAll(xs: IterableOnce[K]): Map.this.type
Removes all elements produced by an iterator from this shrinkable collection.
Removes all elements produced by an iterator from this shrinkable collection.
- xs
the iterator producing the elements to remove.
- returns
the shrinkable collection itself
- Definition Classes
- Shrinkable
-
def
sum: (K, V)
[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 mutable map of numbers of type
Int
. Instead ofInt
, any other typeT
with an implicitNumeric[T]
implementation can be used as element type of the mutable map and as result type ofsum
. Examples of such types are:Long
,Float
,Double
,BigInt
.
- Definition Classes
- IterableOnceOps
Full Signaturedef sum[B >: (K, V)](implicit num: math.Numeric[B]): B
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
def
tail: Map[K, V]
The rest of the collection without its first element.
The rest of the collection without its first element.
- Definition Classes
- IterableOps
-
def
tails: Iterator[Map[K, V]]
Iterates over the tails of this iterable collection.
Iterates over the tails of this iterable collection. The first value will be this iterable collection and the final one will be an empty iterable collection, with the intervening values the results of successive applications of
tail
.- returns
an iterator over all the tails of this iterable collection
- Definition Classes
- IterableOps
List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)
Example: -
def
take(n: Int): Map[K, V]
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 thann
elements. Ifn
is negative, returns an empty iterable collection.
- Definition Classes
- IterableOps → IterableOnceOps
- Note
Reuse: $consumesAndProducesIterator
-
def
takeRight(n: Int): Map[K, V]
A collection containing the last
n
elements of this collection.A collection containing the last
n
elements of this collection.- Definition Classes
- IterableOps
-
def
takeWhile(p: ((K, V)) ⇒ Boolean): Map[K, V]
Takes longest prefix of elements that satisfy a predicate.
Takes longest prefix of elements that satisfy a predicate.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- p
The predicate used to test elements.
- returns
the longest prefix of this iterable collection whose elements all satisfy the predicate
p
.
- Definition Classes
- IterableOps → IterableOnceOps
- Note
Reuse: $consumesAndProducesIterator
-
def
to[C1](factory: Factory[(K, V), C1]): C1
Given a collection factory
factory
, convert this collection to the appropriate representation for the current element typeA
.Given a collection factory
factory
, convert this collection to the appropriate representation for the current element typeA
. Example uses:xs.to(List) xs.to(ArrayBuffer) xs.to(BitSet) // for xs: Iterable[Int]
- Definition Classes
- IterableOnceOps
-
def
toArray[B >: (K, V)](implicit arg0: ClassTag[B]): Array[B]
Convert collection to array.
Convert collection to array.
- Definition Classes
- IterableOnceOps
-
def
toIndexedSeq: immutable.IndexedSeq[(K, V)]
- Definition Classes
- IterableOnceOps
-
final
def
toIterable: Map.this.type
- returns
This collection as an
Iterable[A]
. No new collection will be built ifthis
is already anIterable[A]
.
- Definition Classes
- Iterable → IterableOps
-
def
toList: immutable.List[(K, V)]
- Definition Classes
- IterableOnceOps
-
def
toMap[K, V](implicit ev: <:<[(K, V), (K, V)]): immutable.Map[K, V]
- Definition Classes
- IterableOnceOps
-
def
toSeq: immutable.Seq[(K, V)]
- returns
This collection as a
Seq[A]
. This is equivalent toto(Seq)
but might be faster.
- Definition Classes
- IterableOnceOps
-
def
toSet[B >: (K, V)]: immutable.Set[B]
- Definition Classes
- IterableOnceOps
-
def
toString(): String
Creates a String representation of this object.
Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.
- returns
a String representation of the object.
- Definition Classes
- MapOps → Function1 → IterableOps → AnyRef → Any
-
def
toVector: immutable.Vector[(K, V)]
- Definition Classes
- IterableOnceOps
-
def
transpose[B](implicit asIterable: ((K, V)) ⇒ collection.Iterable[B]): Iterable[Iterable[B]]
Transposes this iterable collection of iterable collections into a iterable collection of iterable collections.
Transposes this iterable collection of iterable collections into a iterable collection of iterable collections.
The resulting collection's type will be guided by the static type of iterable 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 iterable collection.
- asIterable
an implicit conversion which asserts that the element type of this iterable collection is an
Iterable
.- returns
a two-dimensional iterable collection of iterable collections which has as nth row the nth column of this iterable collection.
- Definition Classes
- IterableOps
- Exceptions thrown
IllegalArgumentException
if all collections in this iterable collection are not of the same size.
-
def
unzip[A1, A2](implicit asPair: ((K, V)) ⇒ (A1, A2)): (Iterable[A1], Iterable[A2])
Converts this iterable collection of pairs into two collections of the first and second half of each pair.
Converts this iterable collection of pairs into two collections of the first and second half of each pair.
val xs = Iterable( (1, "one"), (2, "two"), (3, "three")).unzip // xs == (Iterable(1, 2, 3), // Iterable(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 iterable collection is a pair.
- returns
a pair of iterable collections, containing the first, respectively second half of each element pair of this iterable collection.
- Definition Classes
- IterableOps
-
def
unzip3[A1, A2, A3](implicit asTriple: ((K, V)) ⇒ (A1, A2, A3)): (Iterable[A1], Iterable[A2], Iterable[A3])
Converts this iterable collection of triples into three collections of the first, second, and third element of each triple.
Converts this iterable collection of triples into three collections of the first, second, and third element of each triple.
val xs = Iterable( (1, "one", '1'), (2, "two", '2'), (3, "three", '3')).unzip3 // xs == (Iterable(1, 2, 3), // Iterable(one, two, three), // Iterable(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 iterable collection is a triple.
- returns
a triple of iterable collections, containing the first, second, respectively third member of each element triple of this iterable collection.
- Definition Classes
- IterableOps
-
def
update(key: K, value: V): Unit
Adds a new key/value pair to this map.
Adds a new key/value pair to this map. If the map already contains a mapping for the key, it will be overridden by the new value.
- key
The key to update
- value
The new value
- Definition Classes
- MapOps
-
def
values: collection.Iterable[V]
Collects all values of this map in an iterable collection.
Collects all values of this map in an iterable collection.
- returns
the values of this map as an iterable.
- Definition Classes
- MapOps
-
def
valuesIterator(): Iterator[V]
Creates an iterator for all values in this map.
Creates an iterator for all values in this map.
- returns
an iterator over all values that are associated with some key in this map.
- Definition Classes
- MapOps
-
def
view: MapView[K, V]
A view over the elements of this collection.
A view over the elements of this collection.
- Definition Classes
- MapOps → IterableOps
-
final
def
wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
- final def wait(arg0: Long): Unit
-
def
withDefault(d: (K) ⇒ V): WithDefault[K, V]
The same map with a given default function.
The same map with a given default function. Note: The default is only used for
apply
. Other methods likeget
,contains
,iterator
,keys
, etc. are not affected bywithDefaultValue
.Invoking transformer methods (e.g.
map
) will not preserve the default value.- d
the function mapping keys to values, used for non-present keys
- returns
a wrapper of the map with a default value
-
def
withDefaultValue(d: V): WithDefault[K, V]
The same map with a given default value.
The same map with a given default value. Note: The default is only used for
apply
. Other methods likeget
,contains
,iterator
,keys
, etc. are not affected bywithDefaultValue
.Invoking transformer methods (e.g.
map
) will not preserve the default value.- d
default value used for non-present keys
- returns
a wrapper of the map with a default value
-
def
withFilter(p: ((K, V)) ⇒ Boolean): MapWithFilter
Creates a non-strict filter of this map.
Creates a non-strict filter of this map.
Note: the difference between
c filter p
andc withFilter p
is that the former creates a new collection, whereas the latter only restricts the domain of subsequentmap
,flatMap
,foreach
, andwithFilter
operations.Note: might return different results for different runs, unless the underlying collection type is ordered.
- p
the predicate used to test elements.
- returns
an object of class
WithFilter
, which supportsmap
,flatMap
,foreach
, andwithFilter
operations. All these operations apply to those elements of this map which satisfy the predicatep
.
- Definition Classes
- MapOps → IterableOps
-
def
zip[B](that: collection.Iterable[B]): Iterable[((K, V), B)]
Returns a iterable collection formed from this iterable collection and another iterable collection by combining corresponding elements in pairs.
Returns a iterable collection formed from this iterable collection and another iterable collection by combining corresponding elements in pairs. If one of the two collections is longer than the other, its remaining elements are ignored.
- B
the type of the second half of the returned pairs
- that
The iterable providing the second half of each result pair
- returns
a new iterable collection containing pairs consisting of corresponding elements of this iterable collection and
that
. The length of the returned collection is the minimum of the lengths of this iterable collection andthat
.
- Definition Classes
- IterableOps
-
def
zipAll[A1 >: (K, V), B](that: collection.Iterable[B], thisElem: A1, thatElem: B): Iterable[(A1, B)]
Returns a iterable collection formed from this iterable collection and another iterable collection by combining corresponding elements in pairs.
Returns a iterable collection formed from this iterable collection and another iterable collection by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.
- that
the iterable providing the second half of each result pair
- thisElem
the element to be used to fill up the result if this iterable collection is shorter than
that
.- thatElem
the element to be used to fill up the result if
that
is shorter than this iterable collection.- returns
a new collection of type
That
containing pairs consisting of corresponding elements of this iterable collection andthat
. The length of the returned collection is the maximum of the lengths of this iterable collection andthat
. If this iterable collection is shorter thanthat
,thisElem
values are used to pad the result. Ifthat
is shorter than this iterable collection,thatElem
values are used to pad the result.
- Definition Classes
- IterableOps
-
def
zipWithIndex: Iterable[((K, V), Int)]
Zips this iterable collection with its indices.
Zips this iterable collection with its indices.
- returns
A new iterable collection containing pairs consisting of all elements of this iterable collection paired with their index. Indices start at
0
.
- Definition Classes
- IterableOps → IterableOnceOps
List("a", "b", "c").zipWithIndex == List(("a", 0), ("b", 1), ("c", 2))
- Note
Reuse: $consumesAndProducesIterator
Example: -
def
→[B](y: B): (Map[K, V], B)
- Implicit
- This member is added by an implicit conversion from Map[K, V] to ArrowAssoc[Map[K, V]] 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 Map[K, V] to any2stringadd[Map[K, V]] performed by method any2stringadd in scala.Predef.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: any2stringadd[Map[K, V]]).+(other)
- Definition Classes
- any2stringadd
-
def
lazyZip[B](that: collection.Iterable[B]): LazyZip2[(K, V), B, Iterable[(K, V)]]
Analogous to
zip
except that the elements in each collection are not consumed until a strict operation is invoked on the returnedLazyZip2
decorator.Analogous to
zip
except that the elements in each collection are not consumed until a strict operation is invoked on the returnedLazyZip2
decorator.Calls to
lazyZip
can be chained to support higher arities (up to 4) without incurring the expense of constructing and deconstructing intermediary tuples.val xs = List(1, 2, 3) val res = (xs lazyZip xs lazyZip xs lazyZip xs).map((a, b, c, d) => a + b + c + d) // res == List(4, 8, 12)
- B
the type of the second element in each eventual pair
- that
the iterable providing the second element of each eventual pair
- returns
a decorator
LazyZip2
that allows strict operations to be performed on the lazily evaluated pairs or chained calls tolazyZip
. Implicit conversion toIterable[(A, B)]
is also supported.
- Implicit
- This member is added by an implicit conversion from Map[K, V] to LazyZipOps[(K, V), Iterable[(K, V)]] performed by method toLazyZipOps in scala.collection.Iterable.
- Shadowing
- This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
To access this member you can use a type ascription:(map: LazyZipOps[(K, V), Iterable[(K, V)]]).lazyZip(that)
- Definition Classes
- LazyZipOps
-
def
lazyZip[B](that: collection.Iterable[B]): LazyZip2[(K, V), B, Map[K, V]]
Analogous to
zip
except that the elements in each collection are not consumed until a strict operation is invoked on the returnedLazyZip2
decorator.Analogous to
zip
except that the elements in each collection are not consumed until a strict operation is invoked on the returnedLazyZip2
decorator.Calls to
lazyZip
can be chained to support higher arities (up to 4) without incurring the expense of constructing and deconstructing intermediary tuples.val xs = List(1, 2, 3) val res = (xs lazyZip xs lazyZip xs lazyZip xs).map((a, b, c, d) => a + b + c + d) // res == List(4, 8, 12)
- B
the type of the second element in each eventual pair
- that
the iterable providing the second element of each eventual pair
- returns
a decorator
LazyZip2
that allows strict operations to be performed on the lazily evaluated pairs or chained calls tolazyZip
. Implicit conversion toIterable[(A, B)]
is also supported.
- Implicit
- This member is added by an implicit conversion from Map[K, V] to LazyZipOps[(K, V), Map[K, V]] performed by method toLazyZipOps in scala.collection.Map.
- Shadowing
- This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
To access this member you can use a type ascription:(map: LazyZipOps[(K, V), Map[K, V]]).lazyZip(that)
- Definition Classes
- LazyZipOps
-
val
this: Iterable[(K, V)]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to LazyZipOps[(K, V), Iterable[(K, V)]] performed by method toLazyZipOps in scala.collection.Iterable.
- Shadowing
- This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
To access this member you can use a type ascription:(map: LazyZipOps[(K, V), Iterable[(K, V)]]).this
- Definition Classes
- LazyZipOps
-
val
this: Map[K, V]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to LazyZipOps[(K, V), Map[K, V]] performed by method toLazyZipOps in scala.collection.Map.
- Shadowing
- This implicitly inherited member is ambiguous. One or more implicitly inherited members have similar signatures, so calling this member may produce an ambiguous implicit conversion compiler error.
To access this member you can use a type ascription:(map: LazyZipOps[(K, V), Map[K, V]]).this
- Definition Classes
- LazyZipOps
Deprecated Value Members
-
def
+[V1 >: V](kv: (K, V1)): Map[K, V1]
- Definition Classes
- MapOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Consider requiring an immutable Map or fall back to Map.concat
-
def
/:[B](z: B)(op: (B, (K, V)) ⇒ B): B
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)])./:(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator().foldLeft instead of /: on IterableOnce
-
final
def
/:[B](z: B)(op: (B, (K, V)) ⇒ B): B
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use foldLeft instead of /:
-
def
:\[B](z: B)(op: ((K, V), B) ⇒ B): B
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).:\(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator().foldRight instead of :\ on IterableOnce
-
final
def
:\[B](z: B)(op: ((K, V), B) ⇒ B): B
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use foldRight instead of :\
-
def
find(p: ((K, V)) ⇒ Boolean): Option[(K, V)]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).find(p)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator().find instead of .find on IterableOnce
-
def
flatMap[B](f: ((K, V)) ⇒ IterableOnce[B]): IterableOnce[B]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).flatMap(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator().flatMap instead of .flatMap on IterableOnce or consider requiring an Iterable
-
def
foldLeft[B](z: B)(op: (B, (K, V)) ⇒ B): B
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).foldLeft(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator().foldLeft instead of .foldLeft on IterableOnce
-
def
foldRight[B](z: B)(op: ((K, V), B) ⇒ B): B
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).foldRight(z)(op)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator().foldRight instead of .foldLeft on IterableOnce
-
def
foreach[U](f: ((K, V)) ⇒ U): Unit
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).foreach(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator().foreach(...) instead of .foreach(...) on IterableOnce
-
final
def
hasDefiniteSize: Boolean
- Definition Classes
- IterableOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .knownSize >=0 instead of .hasDefiniteSize
-
def
isEmpty: Boolean
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).isEmpty
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator().isEmpty instead of .isEmpty on IterableOnce
-
def
map[B](f: ((K, V)) ⇒ B): IterableOnce[B]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).map(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator().map instead of .map on IterableOnce or consider requiring an Iterable
-
def
mkString: String
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).mkString
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator().mkString instead of .mkString on IterableOnce
-
def
mkString(sep: String): String
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).mkString(sep)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator().mkString instead of .mkString on IterableOnce
-
def
mkString(start: String, sep: String, end: String): String
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).mkString(start, sep, end)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator().mkString instead of .mkString on IterableOnce
-
final
def
retain(p: (K, V) ⇒ Boolean): Map.this.type
Retains only those mappings for which the predicate
p
returnstrue
.Retains only those mappings for which the predicate
p
returnstrue
.- p
The test predicate
- Definition Classes
- MapOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .filterInPlace instead of .retain
-
def
sameElements[B >: A](that: IterableOnce[B]): Boolean
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator().sameElements for sameElements on Iterable or IterableOnce
-
final
def
stringPrefix: String
- Definition Classes
- IterableOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use className instead of stringPrefix
-
def
to[C1](factory: Factory[(K, V), C1]): C1
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).to(factory)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use factory.from(it) instead of it.to(factory) for IterableOnce
-
def
toArray[B >: A](implicit arg0: ClassTag[B]): Array[B]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).toArray(arg0)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use ArrayBuffer.from(it).toArray
-
def
toBuffer[B >: A]: Buffer[B]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).toBuffer
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use ArrayBuffer.from(it) instead of it.toBuffer
-
final
def
toBuffer[B >: (K, V)]: Buffer[B]
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use ArrayBuffer.from(it) instead of it.toBuffer
-
final
def
toIterable: collection.Iterable[(K, V)]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).toIterable
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use Iterable.from(it) instead of it.toIterable
-
def
toIterator: Iterator[(K, V)]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).toIterator
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) toIterator has been renamed to iterator()
-
final
def
toIterator: Iterator[(K, V)]
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator() instead of .toIterator
-
def
toList: immutable.List[(K, V)]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).toList
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use List.from(it) instead of it.toList
-
def
toMap[K, V](implicit ev: <:<[(K, V), (K, V)]): immutable.Map[K, V]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).toMap(ev)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use Map.from(it) instead of it.toVector on IterableOnce
-
def
toSeq: immutable.Seq[(K, V)]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).toSeq
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use Seq.from(it) instead of it.toSeq
-
def
toSet[B >: A]: immutable.Set[B]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).toSet
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use Set.from(it) instead of it.toSet
-
def
toStream: immutable.Stream[(K, V)]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).toStream
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use Stream.from(it) instead of it.toStream
-
final
def
toStream: immutable.Stream[(K, V)]
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use Stream.from(it) instead of it.toStream
-
def
toVector: immutable.Vector[(K, V)]
- Implicit
- This member is added by an implicit conversion from Map[K, V] to IterableOnceExtensionMethods[(K, V)] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(map: IterableOnceExtensionMethods[(K, V)]).toVector
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use Vector.from(it) instead of it.toVector on IterableOnce
-
final
def
transform(f: ((K, V)) ⇒ (K, V)): Map.this.type
- Definition Classes
- IterableOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use
mapInPlace
instead
-
final
def
view(from: Int, until: Int): View[(K, V)]
A view over a slice of the elements of this collection.
A view over a slice of the elements of this collection.
- Definition Classes
- IterableOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .view.slice(from, until) instead of .view(from, until)
This is the documentation for the Scala standard library.
Package structure
The scala package contains core types like
Int
,Float
,Array
orOption
which are accessible in all Scala compilation units without explicit qualification or imports.Notable packages include:
scala.collection
and its sub-packages contain Scala's collections frameworkscala.collection.immutable
- Immutable, sequential data-structures such asVector
,List
,Range
,HashMap
orHashSet
scala.collection.mutable
- Mutable, sequential data-structures such asArrayBuffer
,StringBuilder
,HashMap
orHashSet
scala.collection.concurrent
- Mutable, concurrent data-structures such asTrieMap
scala.concurrent
- Primitives for concurrent programming such asFutures
andPromises
scala.io
- Input and output operationsscala.math
- Basic math functions and additional numeric types likeBigInt
andBigDecimal
scala.sys
- Interaction with other processes and the operating systemscala.util.matching
- Regular expressionsOther packages exist. See the complete list on the right.
Additional parts of the standard library are shipped as separate libraries. These include:
scala.reflect
- Scala's reflection API (scala-reflect.jar)scala.xml
- XML parsing, manipulation, and serialization (scala-xml.jar)scala.collection.parallel
- Parallel collections (scala-parallel-collections.jar)scala.util.parsing
- Parser combinators (scala-parser-combinators.jar)scala.swing
- A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)Automatic imports
Identifiers in the scala package and the
scala.Predef
object are always in scope by default.Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example,
List
is an alias forscala.collection.immutable.List
.Other aliases refer to classes provided by the underlying platform. For example, on the JVM,
String
is an alias forjava.lang.String
.