The implementation class of the set returned by keySet.
The implementation class of the iterable returned by values.
The type implementing this traversable
The type implementing this traversable
A class supporting filtered operations.
Optionally returns the value associated with a key.
Optionally returns the value associated with a key.
the key value
an option value containing the value associated with key in this map,
or None if none exists.
Creates a new iterator over all key/value pairs of this map
Creates a new iterator over all key/value pairs of this map
the new iterator
Test two objects for inequality.
Test two objects for inequality.
true if !(this == that), false otherwise.
Equivalent to x.hashCode except for boxed numeric types and null.
Equivalent to x.hashCode except for boxed numeric types and null.
For numerics, it returns a hash value which is consistent
with value equality: if two value type instances compare
as true, then ## will produce the same hash value for each
of them.
For null returns a hashcode where null.hashCode throws a
NullPointerException.
a hash value consistent with ==
A default implementation which creates a new immutable map.
A default implementation which creates a new immutable map.
the type of the value in the key/value pair.
the key/value pair.
A new map with the new binding added to this map.
Adds two or more elements to this collection and returns a new collection.
Adds a number of elements provided by a traversable object and returns a new collection with the added elements.
Adds a number of elements provided by a traversable object and returns a new collection with the added elements.
the type of the added values
the traversable object consisting of key-value pairs.
a new immutable map with the bindings of this map and those from xs.
[use case] Returns a new immutable map containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new immutable map containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the immutable map is the most specific superclass encompassing the element types of the two operands.
Example:
scala> val a = LinkedList(1) a: scala.collection.mutable.LinkedList[Int] = LinkedList(1) scala> val b = LinkedList(2) b: scala.collection.mutable.LinkedList[Int] = LinkedList(2) scala> val c = a ++ b c: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2) scala> val d = LinkedList('a') d: scala.collection.mutable.LinkedList[Char] = LinkedList(a) scala> val e = c ++ d e: scala.collection.mutable.LinkedList[AnyVal] = LinkedList(1, 2, a)
the element type of the returned collection.
the traversable to append.
a new immutable map which contains all elements of this immutable map
followed by all elements of that.
As with ++, returns a new collection containing the elements from the
left operand followed by the elements from the right operand.
As with ++, returns a new collection containing the elements from the
left operand followed by the elements from the right operand.
It differs from ++ in that the right operand determines the type of
the resulting collection rather than the left one.
Mnemonic: the COLon is on the side of the new COLlection type.
Example:
scala> val x = List(1) x: List[Int] = List(1) scala> val y = LinkedList(2) y: scala.collection.mutable.LinkedList[Int] = LinkedList(2) scala> val z = x ++: y z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)
This overload exists because: for the implementation of ++: we should
reuse that of ++ because many collections override it with more
efficient versions.
Since TraversableOnce has no ++ method, we have to implement that
directly, but Traversable and down can use the overload.
the element type of the returned collection.
the class of the returned collection. Where possible, That is
the same class as the current collection class Repr, but this
depends on the element type B being admissible for that class,
which means that an implicit instance of type CanBuildFrom[Repr, B, That]
is found.
the traversable to append.
an implicit value of class CanBuildFrom which determines
the result class That from the current representation type Repr and
and the new element type B.
a new collection of type That which contains all elements
of this immutable map followed by all elements of that.
[use case] As with ++, returns a new collection containing the elements from the left operand followed by the
elements from the right operand.
As with ++, returns a new collection containing the elements from the left operand followed by the
elements from the right operand.
It differs from ++ in that the right operand determines the type of
the resulting collection rather than the left one.
Mnemonic: the COLon is on the side of the new COLlection type.
Example:
scala> val x = List(1) x: List[Int] = List(1) scala> val y = LinkedList(2) y: scala.collection.mutable.LinkedList[Int] = LinkedList(2) scala> val z = x ++: y z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)
the element type of the returned collection.
the traversable to append.
a new immutable map which contains all elements of this immutable map
followed by all elements of that.
A default implementation which creates a new immutable map.
A default implementation which creates a new immutable map.
the key to be removed
a new map without a binding for key
Creates a new immutable map from this immutable map with some elements removed.
Creates a new immutable map from this immutable map with some elements removed.
This method takes two or more elements to be removed. Another overloaded variant of this method handles the case where a single element is removed.
the first element to remove.
the second element to remove.
the remaining elements to remove.
a new immutable map that contains all elements of the current immutable map except one less occurrence of each of the given elements.
Creates a new immutable map from this immutable map by removing all elements of another collection.
Creates a new immutable map from this immutable map by removing all elements of another collection.
the collection containing the removed elements.
a new immutable map that contains all elements of the current immutable map
except one less occurrence of each of the elements of elems.
Applies a binary operator to a start value and all elements of this immutable map, going left to right.
Applies a binary operator to a start value and all elements of this immutable map, going left to right.
Note: /: is alternate syntax for foldLeft; z /: xs is the same as
xs foldLeft z.
Examples:
Note that the folding function used to compute b is equivalent to that used to compute c.
scala> val a = LinkedList(1,2,3,4) a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4) scala> val b = (5 /: a)(_+_) b: Int = 15 scala> val c = (5 /: a)((x,y) => x + y) c: Int = 15
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op between consecutive elements of this immutable map,
going left to right with the start value z on the left:
op(...op(op(z, x_1), x_2), ..., x_n)
where x1, ..., xn are the elements of this immutable map.
Applies a binary operator to all elements of this immutable map and a start value, going right to left.
Applies a binary operator to all elements of this immutable map and a start value, going right to left.
Note: :\ is alternate syntax for foldRight; xs :\ z is the same as
xs foldRight z.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
Examples:
Note that the folding function used to compute b is equivalent to that used to compute c.
scala> val a = LinkedList(1,2,3,4) a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4) scala> val b = (a :\ 5)(_+_) b: Int = 15 scala> val c = (a :\ 5)((x,y) => x + y) c: Int = 15
the result type of the binary operator.
the start value
the binary operator
the result of inserting op between consecutive elements of this immutable map,
going right to left with the start value z on the right:
op(x_1, op(x_2, ... op(x_n, z)...))
where x1, ..., xn are the elements of this immutable map.
Test two objects for equality.
Test two objects for equality.
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
true if the receiver object is equivalent to the argument; false otherwise.
Appends all bindings of this map to a string builder using start, end, and separator strings.
Appends all bindings of this map to a string builder using start, end, and separator strings.
The written text begins with the string start and ends with the string
end. Inside, the string representations of all bindings of this map
in the form of key -> value are separated by the string sep.
the builder to which strings are appended.
the starting string.
the separator string.
the ending string.
the string builder b to which elements were appended.
Appends all elements of this immutable map to a string builder.
Appends all elements of this immutable map to a string builder.
The written text consists of the string representations (w.r.t. the method
toString) of all elements of this immutable map without any separator string.
Example:
scala> val a = LinkedList(1,2,3,4) a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> val h = a.addString(b) b: StringBuilder = 1234
the string builder to which elements are appended.
the string builder b to which elements were appended.
Appends all elements of this immutable map to a string builder using a separator string.
Appends all elements of this immutable map to a string builder using a separator string.
The written text consists of the string representations (w.r.t. the method toString)
of all elements of this immutable map, separated by the string sep.
Example:
scala> val a = LinkedList(1,2,3,4) a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> a.addString(b, ", ") res0: StringBuilder = 1, 2, 3, 4
the string builder to which elements are appended.
the separator string.
the string builder b to which elements were appended.
Aggregates the results of applying an operator to subsequent elements.
Aggregates the results of applying an operator to subsequent elements.
This is a more general form of fold and reduce. It has similar
semantics, but does not require the result to be a supertype of the
element type. It traverses the elements in different partitions
sequentially, using seqop to update the result, and then applies
combop to results from different partitions. The implementation of
this operation may operate on an arbitrary number of collection
partitions, so combop may be invoked an arbitrary number of times.
For example, one might want to process some elements and then produce
a Set. In this case, seqop would process an element and append it
to the list, while combop would concatenate two lists from different
partitions together. The initial value z would be an empty set.
pc.aggregate(Set[Int]())(_ += process(_), _ ++ _)
Another example is calculating geometric mean from a collection of doubles (one would typically require big doubles for this).
the type of accumulated results
the initial value for the accumulated result of the partition - this
will typically be the neutral element for the seqop operator (e.g.
Nil for list concatenation or 0 for summation)
an operator used to accumulate results within a partition
an associative operator used to combine results from different partitions
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.
the result type of the transformation function.
the transformation function
a partial function with the same domain as this partial function, which maps
arguments x to k(this(x)).
Retrieves the value which is associated with the given key.
Retrieves the value which is associated with the given key. This
method invokes the default method of the map if there is no mapping
from the given key to a value. Unless overridden, the default method throws a
NoSuchElementException.
the key
the value associated with the given key, or the result of the
map's default method, if none exists.
Applies this partial function to the given argument when it is contained in the function domain.
Applies this partial function to the given argument when it is contained in the function domain. Applies fallback function where this partial function is not defined.
Note that expression pf.applyOrElse(x, default) is equivalent to
if(pf isDefinedAt x) pf(x) else default(x)
except that applyOrElse method can be implemented more efficiently.
For all partial function literals compiler generates applyOrElse implementation which
avoids double evaluation of pattern matchers and guards.
This makes applyOrElse the basis for the efficient implementation for many operations and scenarios, such as:
orElse/andThen chains does not lead to
excessive apply/isDefinedAt evaluationlift and unlift 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 override applyOrElse with custom implementation that avoids
double isDefinedAt evaluation. This may result in better performance
and more predictable behavior w.r.t. side effects.
the function argument
the fallback function
the result of this function or fallback function application.
2.10
Cast the receiver object to be of type T0.
Cast the receiver object to be of type T0.
Note that the success of a cast at runtime is modulo Scala's erasure semantics.
Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at
runtime, while the expression List(1).asInstanceOf[List[String]] will not.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the requested type.
the receiver object.
if the receiver object is not an instance of the erasure of type T0.
Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.
Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.
The object with which this immutable map should be compared
true, if this immutable map can possibly equal that, false otherwise. The test
takes into consideration only the run-time types of objects but ignores their elements.
Create a copy of the receiver object.
[use case] Builds a new collection by applying a partial function to all elements of this immutable map on which the function is defined.
Builds a new collection by applying a partial function to all elements of this immutable map on which the function is defined.
the element type of the returned collection.
the partial function which filters and maps the immutable map.
a new immutable 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.
Finds the first element of the immutable map for which the given partial function is defined, and applies the partial function to it.
Finds the first element of the immutable map for which the given partial function is defined, and applies the partial function to it.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the partial function
an option value containing pf applied to the first
value for which it is defined, or None if none exists.
Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)
The factory companion object that builds instances of class immutable.
The factory companion object that builds instances of class immutable.Map.
(or its Iterable superclass where class immutable.Map is not a Seq.)
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.
the type to which function g can be applied
a function A => T1
a new function f such that f(x) == apply(g(x))
Tests whether this map contains a binding for a key.
Tests whether this map contains a binding for a key.
the key
true if there is a binding for key in this map, false otherwise.
[use case] Copies elements of this immutable map to an array.
Copies elements of this immutable map to an array.
Fills the given array xs with at most len elements of
this immutable map, starting at position start.
Copying will stop once either the end of the current immutable map is reached,
or the end of the array is reached, or len elements have been copied.
the array to fill.
the starting index.
the maximal number of elements to copy.
[use case] Copies values of this immutable map to an array.
Copies values of this immutable map to an array.
Fills the given array xs with values of this immutable map.
Copying will stop once either the end of the current immutable map is reached,
or the end of the array is reached.
the array to fill.
[use case] Copies values of this immutable map to an array.
Copies values of this immutable map to an array.
Fills the given array xs with values of this immutable map, beginning at index start.
Copying will stop once either the end of the current immutable map is reached,
or the end of the array is reached.
the array to fill.
the starting index.
Copies all elements of this immutable map to a buffer.
Copies all elements of this immutable map to a buffer.
The buffer to which elements are copied.
Counts the number of elements in the immutable map which satisfy a predicate.
Counts the number of elements in the immutable map which satisfy a predicate.
the predicate used to test elements.
the number of elements satisfying the predicate p.
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.
the given key value for which a binding is missing.
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.
the number of elements to drop from this immutable map.
a immutable map consisting of all elements of this immutable map except the first n ones, or else the
empty immutable map, if this immutable map has less than n elements.
Selects all elements except last n ones.
Selects all elements except last n ones.
Note: might return different results for different runs, unless the underlying collection type is ordered.
The number of elements to take
a immutable map consisting of all elements of this immutable map except the last n ones, or else the
empty immutable map, if this immutable map has less than n elements.
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.
the longest suffix of this immutable map whose first element
does not satisfy the predicate p.
The empty map of the same type as this map
Tests whether the argument (arg0) is a reference to the receiver object (this).
Tests whether the argument (arg0) is a reference to the receiver object (this).
The eq method implements an equivalence relation on
non-null instances of AnyRef, and has three additional properties:
x and y of type AnyRef, multiple invocations of
x.eq(y) consistently returns true or consistently returns false.x of type AnyRef, x.eq(null) and null.eq(x) returns false.null.eq(null) returns true. When overriding the equals or hashCode methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they
should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).
true if the argument is a reference to the receiver object; false otherwise.
Compares two maps structurally; i.
Compares two maps structurally; i.e. checks if all mappings contained in this map are also contained in the other map, and vice versa.
the other map
true if both maps contain exactly the
same mappings, false otherwise.
Tests whether a predicate holds for some of the elements of this immutable map.
Tests whether a predicate holds for some of the elements of this immutable map.
the predicate used to test elements.
true if the given predicate p holds for some of the
elements of this immutable map, otherwise false.
Selects all elements of this immutable map which satisfy a predicate.
Selects all elements of this immutable map which satisfy a predicate.
the predicate used to test elements.
a new immutable map consisting of all elements of this immutable map that satisfy the given
predicate p. The order of the elements is preserved.
Filters this map by retaining only keys satisfying a predicate.
Filters this map by retaining only keys satisfying a predicate.
the predicate used to test keys
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.
Returns a new map obtained by removing all key/value pairs for which the predicate
p returns true.
Returns a new map obtained by removing all key/value pairs for which the predicate
p returns true.
Note: This method works by successively removing elements for which the
predicate is true from this set.
If removal is slow, or you expect that most elements of the set
will be removed, you might consider using filter
with a negated predicate instead.
A predicate over key-value pairs
A new map containing elements not satisfying the predicate.
Called by the garbage collector on the receiver object when there are no more references to the object.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize method is invoked, as
well as the interaction between finalize and non-local returns
and exceptions, are all platform dependent.
Finds the first element of the immutable map satisfying a predicate, if any.
Finds the first element of the immutable map satisfying a predicate, if any.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the predicate used to test elements.
an option value containing the first element in the immutable map
that satisfies p, or None if none exists.
[use case] Builds a new collection by applying a function to all elements of this immutable map and using the elements of the resulting collections.
Builds a new collection by applying a function to all elements of this immutable map and using the elements of the resulting collections.
For example:
def getWords(lines: Seq[String]): Seq[String] = lines flatMap (line => line split "\\W+")
The type of the resulting collection is guided by the static type of immutable map. This might cause unexpected results sometimes. For example:
// lettersOf will return a Seq[Char] of likely repeated letters, instead of a Set def lettersOf(words: Seq[String]) = words flatMap (word => word.toSet) // lettersOf will return a Set[Char], not a Seq def lettersOf(words: Seq[String]) = words.toSet flatMap (word => word.toSeq) // xs will be a 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)
the element type of the returned collection.
the function to apply to each element.
a new immutable map resulting from applying the given collection-valued function
f to each element of this immutable map and concatenating the results.
[use case] Converts this immutable map of traversable collections into a immutable map formed by the elements of these traversable collections.
Converts this immutable map of traversable collections into a immutable map formed by the elements of these traversable collections.
The resulting collection's type will be guided by the static type of immutable map. For example:
val xs = List(Set(1, 2, 3), Set(1, 2, 3)) // xs == List(1, 2, 3, 1, 2, 3) val ys = Set(List(1, 2, 3), List(3, 2, 1)) // ys == Set(1, 2, 3)
the type of the elements of each traversable collection.
a new immutable map resulting from concatenating all element immutable maps.
Folds the elements of this immutable map using the specified associative binary operator.
Folds the elements of this immutable map using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
a type parameter for the binary operator, a supertype of A.
a neutral element for the fold operation; may be added to the result
an arbitrary number of times, and must not change the result (e.g., Nil for list concatenation,
0 for addition, or 1 for multiplication.)
a binary operator that must be associative
the result of applying fold operator op between all the elements and z
Applies a binary operator to a start value and all elements of this immutable map, going left to right.
Applies a binary operator to a start value and all elements of this immutable map, going left to right.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op between consecutive elements of this immutable map,
going left to right with the start value z on the left:
op(...op(z, x_1), x_2, ..., x_n)
where x1, ..., xn are the elements of this immutable map.
Applies a binary operator to all elements of this immutable map and a start value, going right to left.
Applies a binary operator to all elements of this immutable map and a start value, going right to left.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op between consecutive elements of this immutable map,
going right to left with the start value z on the right:
op(x_1, op(x_2, ... op(x_n, z)...))
where x1, ..., xn are the elements of this immutable map.
Tests whether a predicate holds for all elements of this immutable map.
Tests whether a predicate holds for all elements of this immutable map.
the predicate used to test elements.
true if the given predicate p holds for all elements
of this immutable map, otherwise false.
[use case] Applies a function f to all elements of this immutable map.
Applies a function f to all elements of this immutable map.
Note: this method underlies the implementation of most other bulk operations. Subclasses should re-implement this method if a more efficient implementation exists.
the function that is applied for its side-effect to every element.
The result of function f is discarded.
Returns string formatted according to given format string.
Returns string formatted according to given format string.
Format strings are as for String.format
(@see java.lang.String.format).
The generic builder that builds instances of immutable.
The generic builder that builds instances of immutable.Map at arbitrary element types.
A representation that corresponds to the dynamic class of the receiver object.
A representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
not specified by SLS as a member of AnyRef
[use case] Returns the value associated with a key, or a default value if the key is not contained in the map.
Returns the value associated with a key, or a default value if the key is not contained in the map.
the key.
a computation that yields a default value in case no binding for key is
found in the map.
the value associated with key if it exists,
otherwise the result of the default computation.
Partitions this immutable map into a map of immutable maps according to some discriminator function.
Partitions this immutable map into a map of immutable maps according to some discriminator function.
Note: this method is not re-implemented by views. This means when applied to a view it will always force the view and return a new immutable map.
the type of keys returned by the discriminator function.
the discriminator function.
A map from keys to immutable maps such that the following invariant holds:
(xs partition f)(k) = xs filter (x => f(x) == k) That is, every key k is bound to a immutable map of those elements x
for which f(x) equals k.
Partitions elements in fixed size immutable maps.
Partitions elements in fixed size immutable maps.
the number of elements per group
An iterator producing immutable maps of size size, except the
last will be truncated if the elements don't divide evenly.
scala.collection.Iterator, method grouped
Tests whether this immutable map is known to have a finite size.
Tests whether this immutable map is known to have a finite size.
All strict collections are known to have finite size. For a non-strict
collection such as Stream, the predicate returns true if all
elements have been computed. It returns false if the stream is
not yet evaluated to the end.
Note: many collection methods will not work on collections of infinite sizes.
true if this collection is known to have finite size,
false otherwise.
The hashCode method for reference types.
The hashCode method for reference types. See hashCode in scala.Any.
the hash code value for this object.
Selects the first element of this immutable map.
Selects the first element of this immutable map.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the first element of this immutable map.
if the immutable map is empty.
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.
the first element of this immutable map if it is nonempty,
None if it is empty.
Selects all elements except the last.
Selects all elements except the last.
Note: might return different results for different runs, unless the underlying collection type is ordered.
a immutable map consisting of all elements of this immutable map except the last one.
if the immutable map is empty.
Iterates over the inits of this immutable map.
Iterates over the inits of this immutable map. The first value will be this
immutable map and the final one will be an empty immutable map, with the intervening
values the results of successive applications of init.
an iterator over all the inits of this immutable map
List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)
Tests whether this map contains a binding for a key.
Tests whether this map contains a binding for a key. This method,
which implements an abstract method of trait PartialFunction,
is equivalent to contains.
the key
true if there is a binding for key in this map, false otherwise.
Tests whether the map is empty.
Tests whether the map is empty.
true if the map does not contain any key/value binding, false otherwise.
Test whether the dynamic type of the receiver object is T0.
Test whether the dynamic type of the receiver object is T0.
Note that the result of the test is modulo Scala's erasure semantics.
Therefore the expression 1.isInstanceOf[String] will return false, while the
expression List(1).isInstanceOf[List[String]] will return true.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the specified type.
true if the receiver object is an instance of erasure of type T0; false otherwise.
Tests whether this immutable map can be repeatedly traversed.
Tests whether this immutable map can be repeatedly traversed.
true
Collects all keys of this map in a set.
Collects all keys of this map in a set.
a set containing all keys of this map.
Collects all keys of this map in an iterable collection.
Collects all keys of this map in an iterable collection.
the keys of this map as an iterable.
(Changed in version 2.8.0) keys returns Iterable[A] rather than Iterator[A].
Creates an iterator for all keys.
Creates an iterator for all keys.
an iterator over all keys.
Selects the last element.
Selects the last element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
The last element of this immutable map.
If the immutable map is empty.
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.
the last element of this immutable map$ if it is nonempty,
None if it is empty.
Turns this partial function into an plain function returning an Option result.
Turns this partial function into an plain function returning an Option result.
a function that takes an argument x to Some(this(x)) if this
is defined for x, and to None otherwise.
Function.unlift
[use case] Builds a new collection by applying a function to all elements of this immutable map.
Builds a new collection by applying a function to all elements of this immutable map.
the element type of the returned collection.
the function to apply to each element.
a new immutable map resulting from applying the given function
f to each element of this immutable map and collecting the results.
Transforms this map by applying a function to every retrieved value.
Transforms this map by applying a function to every retrieved value.
the function used to transform values of this map.
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.
[use case] Finds the largest element.
Finds the largest element.
the largest element of this immutable map.
[use case] Finds the smallest element.
Finds the smallest element.
the smallest element of this immutable map
Displays all elements of this immutable map in a string.
Displays all elements of this immutable map in a string.
a string representation of this immutable map. In the resulting string
the string representations (w.r.t. the method toString)
of all elements of this immutable map follow each other without any
separator string.
Displays all elements of this immutable map in a string using a separator string.
Displays all elements of this immutable map in a string using a separator string.
the separator string.
a string representation of this immutable map. In the resulting string
the string representations (w.r.t. the method toString)
of all elements of this immutable map are separated by the string sep.
List(1, 2, 3).mkString("|") = "1|2|3"
Displays all elements of this immutable map in a string using start, end, and separator strings.
Displays all elements of this immutable map in a string using start, end, and separator strings.
the starting string.
the separator string.
the ending string.
a string representation of this immutable map. The resulting string
begins with the string start and ends with the string
end. Inside, the string representations (w.r.t. the method
toString) of all elements of this immutable map are separated by
the string sep.
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
Equivalent to !(this eq that).
Equivalent to !(this eq that).
true if the argument is not a reference to the receiver object; false otherwise.
A common implementation of newBuilder for all maps in terms of empty.
A common implementation of newBuilder for all maps in terms of empty.
Overridden for mutable maps in mutable.MapLike.
Tests whether the immutable map is not empty.
Tests whether the immutable map is not empty.
true if the immutable map contains at least one element, false otherwise.
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.
not specified by SLS as a member of AnyRef
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.
not specified by SLS as a member of AnyRef
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.
the argument type of the fallback function
the result type of the fallback function
the fallback function
a partial function which has as domain the union of the domains
of this partial function and that. The resulting partial function
takes x to this(x) where this is defined, and to that(x) where it is not.
Returns a parallel implementation of this collection.
Returns a parallel implementation of this collection.
For most collection types, this method creates a new parallel collection by copying
all the elements. For these collection, par takes linear time. Mutable collections
in this category do not produce a mutable parallel collection that has the same
underlying dataset, so changes in one collection will not be reflected in the other one.
Specific collections (e.g. ParArray or mutable.ParHashMap) override this default
behaviour by creating a parallel collection which shares the same underlying dataset.
For these collections, par takes constant or sublinear time.
All parallel collections return a reference to themselves.
a parallel implementation of this collection
The default par implementation uses the combiner provided by this method
to create a new parallel collection.
The default par implementation uses the combiner provided by this method
to create a new parallel collection.
a combiner for the parallel collection of type ParRepr
Partitions this immutable map in two immutable maps according to a predicate.
Partitions this immutable map in two immutable maps according to a predicate.
the predicate on which to partition.
a pair of immutable maps: the first immutable map consists of all elements that
satisfy the predicate p and the second immutable map consists of all elements
that don't. The relative order of the elements in the resulting immutable maps
is the same as in the original immutable map.
[use case] Multiplies up the elements of this collection.
Multiplies up the elements of this collection.
the product of all elements in this immutable map of numbers of type Int.
Instead of Int, any other type T with an implicit Numeric[T] implementation
can be used as element type of the immutable map and as result type of product.
Examples of such types are: Long, Float, Double, BigInt.
Reduces the elements of this immutable map using the specified associative binary operator.
Reduces the elements of this immutable map using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
A type parameter for the binary operator, a supertype of A.
A binary operator that must be associative.
The result of applying reduce operator op between all the elements if the immutable map is nonempty.
if this immutable map is empty.
Applies a binary operator to all elements of this immutable map, going left to right.
Applies a binary operator to all elements of this immutable map, going left to right.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the binary operator.
the result of inserting op between consecutive elements of this immutable map,
going left to right:
op( op( ... op(x_1, x_2) ..., x_{n-1}), x_n) where x1, ..., xn are the elements of this immutable map.
if this immutable map is empty.
Optionally applies a binary operator to all elements of this immutable map, going left to right.
Optionally applies a binary operator to all elements of this immutable map, going left to right.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the binary operator.
an option value containing the result of reduceLeft(op) is this immutable map is nonempty,
None otherwise.
Reduces the elements of this immutable map, if any, using the specified associative binary operator.
Reduces the elements of this immutable map, if any, using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
A type parameter for the binary operator, a supertype of A.
A binary operator that must be associative.
An option value containing result of applying reduce operator op between all
the elements if the collection is nonempty, and None otherwise.
Applies a binary operator to all elements of this immutable map, going right to left.
Applies a binary operator to all elements of this immutable map, going right to left.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the binary operator.
the result of inserting op between consecutive elements of this immutable map,
going right to left:
op(x_1, op(x_2, ..., op(x_{n-1}, x_n)...)) where x1, ..., xn are the elements of this immutable map.
if this immutable map is empty.
Optionally applies a binary operator to all elements of this immutable map, going right to left.
Optionally applies a binary operator to all elements of this immutable map, going right to left.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the binary operator.
an option value containing the result of reduceRight(op) is this immutable map is nonempty,
None otherwise.
The collection of type immutable map underlying this TraversableLike object.
The collection of type immutable map underlying this TraversableLike object.
By default this is implemented as the TraversableLike object itself,
but this can be overridden.
Composes this partial function with an action function which gets applied to results of this partial function.
Composes this partial function with an action function which gets applied to results of this partial function. The action function is invoked only for its side effects; its result is ignored.
Note that expression pf.runWith(action)(x) is equivalent to
if(pf isDefinedAt x) { action(pf(x)); true } else false
except that runWith is implemented via applyOrElse and thus potentially more efficient.
Using runWith avoids double evaluation of pattern matchers and guards for partial function literals.
the action function
a function which maps arguments x to isDefinedAt(x). The resulting function
runs action(this(x)) where this is defined.
2.10
applyOrElse.
[use case] Checks if the other iterable collection contains the same elements in the same order as this immutable map.
Checks if the other iterable collection contains the same elements in the same order as this immutable map.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the collection to compare with.
true, if both collections contain the same elements in the same order, false otherwise.
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.
element type of the resulting collection
type of the resulting collection
neutral element for the operator op
the associative operator for the scan
combiner factory which provides a combiner
a new immutable map containing the prefix scan of the elements in this immutable map
Produces a collection containing cumulative results of applying the operator going left to right.
Produces a collection containing cumulative results of applying the operator going left to right.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the type of the elements in the resulting collection
the actual type of the resulting collection
the initial value
the binary operator applied to the intermediate result and the element
an implicit value of class CanBuildFrom which determines
the result class That from the current representation type Repr and
and the new element type B.
collection with intermediate results
Produces a collection containing cumulative results of applying the operator going right to left.
Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.
Note: might return different results for different runs, unless the underlying collection type is ordered.
Example:
List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)
the type of the elements in the resulting collection
the actual type of the resulting collection
the initial value
the binary operator applied to the intermediate result and the element
an implicit value of class CanBuildFrom which determines
the result class That from the current representation type Repr and
and the new element type B.
collection with intermediate results
(Changed in version 2.9.0) The behavior of scanRight has changed. The previous behavior can be reproduced with scanRight.reverse.
A version of this collection with all of the operations implemented sequentially (i.
A version of this collection with all of the operations implemented sequentially (i.e. in a single-threaded manner).
This method returns a reference to this collection. In parallel collections, it is redefined to return a sequential implementation of this collection. In both cases, it has O(1) complexity.
a sequential view of the collection.
The size of this immutable map.
The size of this immutable map.
the number of elements in this immutable map.
Selects an interval of elements.
Selects an interval of elements. The returned collection is made up
of all elements x which satisfy the invariant:
from <= indexOf(x) < until
Note: might return different results for different runs, unless the underlying collection type is ordered.
a immutable map containing the elements greater than or equal to
index from extending up to (but not including) index until
of this immutable map.
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.)
the number of elements per group
the distance between the first elements of successive groups (defaults to 1)
An iterator producing immutable maps of size size, except the
last and the only element will be truncated if there are
fewer elements than size.
scala.collection.Iterator, method sliding
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.)
the number of elements per group
An iterator producing immutable maps of size size, except the
last and the only element will be truncated if there are
fewer elements than size.
scala.collection.Iterator, method sliding
Splits this immutable map into a prefix/suffix pair according to a predicate.
Splits this immutable map into a prefix/suffix pair according to a predicate.
Note: c span p is equivalent to (but possibly more efficient than)
(c takeWhile p, c dropWhile p), provided the evaluation of the
predicate p does not cause any side-effects.
Note: might return different results for different runs, unless the underlying collection type is ordered.
a pair consisting of the longest prefix of this immutable map whose
elements all satisfy p, and the rest of this immutable map.
Splits this immutable map into two at a given position.
Splits this immutable map 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.
the position at which to split.
a pair of immutable maps consisting of the first n
elements of this immutable map, and the other elements.
Defines the prefix of this object's toString representation.
Defines the prefix of this object's toString representation.
a string representation which starts the result of toString applied to this immutable map.
Unless overridden in subclasses, the string prefix of every map is "Map".
[use case] Sums up the elements of this collection.
Sums up the elements of this collection.
the sum of all elements in this immutable map of numbers of type Int.
Instead of Int, any other type T with an implicit Numeric[T] implementation
can be used as element type of the immutable map and as result type of sum.
Examples of such types are: Long, Float, Double, BigInt.
Selects all elements except the first.
Selects all elements except the first.
Note: might return different results for different runs, unless the underlying collection type is ordered.
a immutable map consisting of all elements of this immutable map except the first one.
if the immutable map is empty.
Iterates over the tails of this immutable map.
Iterates over the tails of this immutable map. The first value will be this
immutable map and the final one will be an empty immutable map, with the intervening
values the results of successive applications of tail.
an iterator over all the tails of this immutable map
List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)
Selects first n elements.
Selects first n elements.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the number of elements to take from this immutable map.
a immutable map consisting only of the first n elements of this immutable map,
or else the whole immutable map, if it has less than n elements.
Selects last n elements.
Selects last n elements.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the number of elements to take
a immutable map consisting only of the last n elements of this immutable map, or else the
whole immutable map, if it has less than n elements.
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.
the longest prefix of this immutable map whose elements all satisfy
the predicate p.
The underlying collection seen as an instance of immutable.Map.
The underlying collection seen as an instance of immutable.Map.
By default this is implemented as the current collection object itself,
but this can be overridden.
[use case] Converts this immutable map into another by copying all elements.
Converts this immutable map into another by copying all elements.
The collection type to build.
a new collection containing all elements of this immutable map.
[use case] Converts this immutable map to an array.
Converts this immutable map to an array.
an array containing all elements of this immutable map.
An ClassTag must be available for the element type of this immutable map.
Converts this immutable map to a mutable buffer.
Converts this immutable map to a mutable buffer.
a buffer containing all elements of this immutable map.
A conversion from collections of type Repr to immutable.Map objects.
A conversion from collections of type Repr to immutable.Map objects.
By default this is implemented as just a cast, but this can be overridden.
Converts this immutable map to an indexed sequence.
Converts this immutable map to an indexed sequence.
an indexed sequence containing all elements of this immutable map.
Converts this immutable map to an iterable collection.
Converts this immutable map to an iterable collection. Note that
the choice of target Iterable is lazy in this default implementation
as this TraversableOnce may be lazy and unevaluated (i.e. it may
be an iterator which is only traversable once).
an Iterable containing all elements of this immutable map.
Returns an Iterator over the elements in this immutable map.
Returns an Iterator over the elements in this immutable map. Will return the same Iterator if this instance is already an Iterator.
an Iterator containing all elements of this immutable map.
Converts this immutable map to a list.
Converts this immutable map to a list.
a list containing all elements of this immutable map.
[use case] Converts this immutable map to a map.
Converts this immutable map to a map. This method is unavailable unless the elements are members of Tuple2, each ((T, U)) becoming a key-value pair in the map. Duplicate keys will be overwritten by later keys: if this is an unordered collection, which key is in the resulting map is undefined.
a map of type immutable.Map[T, U]
containing all key/value pairs of type (T, U) of this immutable map.
Converts this immutable map to a sequence.
Converts this immutable map to a sequence. As with toIterable, it's lazy
in this default implementation, as this TraversableOnce may be
lazy and unevaluated.
a sequence containing all elements of this immutable map.
Converts this immutable map to a set.
Converts this immutable map to a set.
a set containing all elements of this immutable map.
Converts this immutable map to a stream.
Converts this immutable map to a stream.
a stream containing all elements of this immutable map.
Converts this immutable map to a string.
Converts this immutable map to a string.
a string representation of this collection. By default this
string consists of the stringPrefix of this immutable map, followed
by all elements separated by commas and enclosed in parentheses.
Converts this immutable map to an unspecified Traversable.
Converts this immutable map to an unspecified Traversable. Will return the same collection if this instance is already Traversable.
a Traversable containing all elements of this immutable map.
Converts this immutable map to a Vector.
Converts this immutable map to a Vector.
a vector containing all elements of this immutable map.
This function transforms all the values of mappings contained
in this map with function f.
This function transforms all the values of mappings contained
in this map with function f.
A function over keys and values
the updated map
Transposes this immutable map of traversable collections into a immutable map of immutable maps.
Transposes this immutable map of traversable collections into a immutable map of immutable maps.
the type of the elements of each traversable collection.
an implicit conversion which asserts that the
element type of this immutable map is a Traversable.
a two-dimensional immutable map of immutable maps which has as nth row the nth column of this immutable map.
(Changed in version 2.9.0) transpose throws an IllegalArgumentException if collections are not uniformly sized.
if all collections in this immutable map are not of the same size.
Converts this immutable map of pairs into two collections of the first and second half of each pair.
Converts this immutable map of pairs into two collections of the first and second half of each pair.
the type of the first half of the element pairs
the type of the second half of the element pairs
an implicit conversion which asserts that the element type of this immutable map is a pair.
a pair immutable maps, containing the first, respectively second half of each element pair of this immutable map.
Converts this immutable map of triples into three collections of the first, second, and third element of each triple.
Converts this immutable map of triples into three collections of the first, second, and third element of each triple.
the type of the first member of the element triples
the type of the second member of the element triples
the type of the third member of the element triples
an implicit conversion which asserts that the element type of this immutable map is a triple.
a triple immutable maps, containing the first, second, respectively third member of each element triple of this immutable map.
A new immutable map containing updating this map with a given key/value mapping.
Collects all values of this map in an iterable collection.
Collects all values of this map in an iterable collection.
the values of this map as an iterable.
(Changed in version 2.8.0) values returns Iterable[B] rather than Iterator[B].
Creates an iterator for all values in this map.
Creates an iterator for all values in this map.
an iterator over all values that are associated with some key in this map.
Creates a non-strict view of a slice of this immutable map.
Creates a non-strict view of a slice of this immutable map.
Note: the difference between view and slice is that view produces
a view of the current immutable map, whereas slice produces a new immutable map.
Note: view(from, to) is equivalent to view.slice(from, to)
Note: might return different results for different runs, unless the underlying collection type is ordered.
the index of the first element of the view
the index of the element following the view
a non-strict view of a slice of this immutable map, starting at index from
and extending up to (but not including) index until.
Creates a non-strict view of this immutable map.
Creates a non-strict view of this immutable map.
a non-strict view of this immutable map.
The same map with a given default function.
The same map with a given default function.
Note: get, contains, iterator, keys, etc are not affected by withDefault.
Invoking transformer methods (e.g. map) will not preserve the default value.
the function mapping keys to values, used for non-present keys
a wrapper of the map with a default value
The same map with a given default value.
The same map with a given default value.
Note: get, contains, iterator, keys, etc are not affected by withDefaultValue.
Invoking transformer methods (e.g. map) will not preserve the default value.
the function mapping keys to values, used for non-present keys
a wrapper of the map with a default value
Creates a non-strict filter of this immutable map.
Creates a non-strict filter of this immutable map.
Note: the difference between c filter p and c withFilter p is that
the former creates a new collection, whereas the latter only
restricts the domain of subsequent map, flatMap, foreach,
and withFilter operations.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the predicate used to test elements.
an object of class WithFilter, which supports
map, flatMap, foreach, and withFilter operations.
All these operations apply to those elements of this immutable map
which satisfy the predicate p.
[use case] Returns a immutable map formed from this immutable map and another iterable collection by combining corresponding elements in pairs.
Returns a immutable map formed from this immutable map and another iterable collection by combining corresponding elements in pairs. If one of the two collections is longer than the other, its remaining elements are ignored.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the type of the second half of the returned pairs
The iterable providing the second half of each result pair
a new immutable map containing pairs consisting of
corresponding elements of this immutable map and that. The length
of the returned collection is the minimum of the lengths of this immutable map and that.
[use case] Returns a immutable map formed from this immutable map and another iterable collection by combining corresponding elements in pairs.
Returns a immutable map formed from this immutable map and another iterable collection by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the type of the second half of the returned pairs
The iterable providing the second half of each result pair
the element to be used to fill up the result if this immutable map is shorter than that.
the element to be used to fill up the result if that is shorter than this immutable map.
a new immutable map containing pairs consisting of
corresponding elements of this immutable map and that. The length
of the returned collection is the maximum of the lengths of this immutable map and that.
If this immutable map is shorter than that, thisElem values are used to pad the result.
If that is shorter than this immutable map, thatElem values are used to pad the result.
[use case] Zips this immutable map with its indices.
Zips this immutable map with its indices.
Note: might return different results for different runs, unless the underlying collection type is ordered.
A new immutable map containing pairs consisting of all elements of this
immutable map paired with their index. Indices start at 0.
List("a", "b", "c").zipWithIndex = List(("a", 0), ("b", 1), ("c", 2))
(defaultMap: StringAdd).+(other)
(defaultMap: MonadOps[(A, B)]).filter(p)
(defaultMap: MonadOps[(A, B)]).flatMap(f)
(defaultMap: MonadOps[(A, B)]).map(f)
(defaultMap: StringAdd).self
(defaultMap: StringFormat).self
(defaultMap: MonadOps[(A, B)]).withFilter(p)
A syntactic sugar for out of order folding.
A syntactic sugar for out of order folding. See fold.
Example:
scala> val a = LinkedList(1,2,3,4) a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4) scala> val b = (a /:\ 5)(_+_) b: Int = 15
(Since version 2.10.0) use fold instead
(defaultMap: ArrowAssoc[DefaultMap[A, B]]).x
(Since version 2.10.0) Use leftOfArrow instead
(defaultMap: Ensuring[DefaultMap[A, B]]).x
(Since version 2.10.0) Use resultOfEnsuring instead
A default map which implements the
+and-methods of maps. It does so using the default builder for maps defined in theMapobject. Instances that inherit fromDefaultMap[A, B]still have to define:It refers back to the original map.
It might also be advisable to override
foreachorsizeif efficient implementations can be found.the type of the keys contained in this map.
the type of the values associated with the keys.
2.8