SortedSet
public struct SortedSet<Element: Comparable>: SetAlgebra
A sorted collection of unique comparable elements.
SortedSet
is like Set
in the standard library, but it always keeps its elements in ascending order.
Lookup, insertion and removal of any element has logarithmic complexity.
SortedSet
is a struct with copy-on-write value semantics, like Swift’s standard collection types.
It uses an in-memory b-tree for element storage, whose individual nodes may be shared with other sorted sets.
Mutating a set whose storage is (partially or completely) shared requires copying of only O(log(count
)) elements.
(Thus, mutation of shared SortedSet
s may be cheaper than ordinary Set
s, which need to copy all elements.)
Set operations on sorted sets (such as taking the union, intersection or difference) can take as little as O(log(n)) time if the elements in the input sets aren’t too interleaved.
See also
SortedBag
-
Create an empty set.
Declaration
Swift
public init()
-
Create a set from a finite sequence of items. The sequence need not be sorted. If the sequence contains duplicate items, only the last instance will be kept in the set.
Complexity
O(n * log(n)), where n is the number of items in the sequence.Declaration
Swift
public init<S: Sequence>(_ elements: S) where S.Iterator.Element == Element
-
Create a set from a sorted finite sequence of items. If the sequence contains duplicate items, only the last instance will be kept in the set.
Complexity
O(n), where n is the number of items in the sequence.Declaration
Swift
public init<S: Sequence>(sortedElements elements: S) where S.Iterator.Element == Element
-
Create a set with the specified list of items. If the array literal contains duplicate items, only the last instance will be kept.
Declaration
Swift
public init(arrayLiteral elements: Element...)
-
Returns the element at the given index.
Requires
index
originated from an unmutated copy of this set.Complexity
O(1)Declaration
Swift
public subscript(index: Index) -> Element
-
Return the subset consisting of elements in the given range of indexes.
Requires
The indices inrange
originated from an unmutated copy of this set.Complexity
O(log(count
))Declaration
Swift
public subscript(range: Range<Index>) -> SortedSet<Element>
-
The
past-the-end
element index; the successor of the last valid subscript argument.Complexity
O(1)Declaration
Swift
public var endIndex: Index
-
The number of elements in this set.
Declaration
Swift
public var count: Int
-
True iff this collection has no elements.
Declaration
Swift
public var isEmpty: Bool
-
Return an iterator over all elements in this map, in ascending key order.
Declaration
Swift
public func makeIterator() -> Iterator
-
Returns the successor of the given index.
Complexity
Amortized O(1).Declaration
Swift
public func index(after index: Index) -> Index
-
Replaces the given index with its successor.
Complexity
Amortized O(1).Declaration
Swift
public func formIndex(after index: inout Index)
-
Returns the predecessor of the given index.
Complexity
Amortized O(1).Declaration
Swift
public func index(before index: Index) -> Index
-
Replaces the given index with its predecessor.
Complexity
Amortized O(1).Declaration
Swift
public func formIndex(before index: inout Index)
-
Returns an index that is at the specified distance from the given index.
Requires
index
must be a valid index of this set. Ifn
is positive, it must not exceed the distance fromindex
toendIndex
. Ifn
is negative, it must not be less than the distance fromindex
tostartIndex
.Complexity
O(log(count)) where count is the number of elements in the set.Declaration
Swift
public func index(_ i: Index, offsetBy n: Int) -> Index
-
Offsets the given index by the specified distance.
Requires
index
must be a valid index of this set. Ifn
is positive, it must not exceed the distance fromindex
toendIndex
. Ifn
is negative, it must not be less than the distance fromindex
tostartIndex
.Complexity
O(log(count)) where count is the number of elements in the set.Declaration
Swift
public func formIndex(_ i: inout Index, offsetBy n: Int)
-
Returns an index that is at the specified distance from the given index, unless that distance is beyond a given limiting index.
Requires
index
andlimit
must be valid indices in this set. The operation must not advance the index beyondendIndex
or beforestartIndex
.Complexity
O(log(count)) where count is the number of elements in the set.Declaration
Swift
public func index(_ i: Index, offsetBy n: Int, limitedBy limit: Index) -> Index?
-
Offsets the given index by the specified distance, or so that it equals the given limiting index.
Requires
index
andlimit
must be valid indices in this set. The operation must not advance the index beyondendIndex
or beforestartIndex
.Complexity
O(log(count)) where count is the number of elements in the set.Declaration
Swift
public func formIndex(_ i: inout Index, offsetBy n: Int, limitedBy limit: Index) -> Bool
-
Returns the distance between two indices.
Requires
start
andend
must be valid indices in this set.Complexity
O(1)Declaration
Swift
public func distance(from start: Index, to end: Index) -> Int
-
Returns the element at
offset
from the start of the set.Complexity
O(log(count
))Declaration
Swift
public subscript(offset: Int) -> Element
-
Returns the subset containing elements in the specified range of offsets from the start of the set.
Complexity
O(log(count
))Declaration
Swift
public subscript(offsetRange: Range<Int>) -> SortedSet<Element>
-
Return the offset of
member
, if it is an element of this set. Otherwise, returnnil
.Complexity
O(log(count
))Declaration
Swift
public func offset(of member: Element) -> Int?
-
Returns the offset of the element at
index
.Complexity
O(log(count
))Declaration
Swift
public func index(ofOffset offset: Int) -> Index
-
Returns the index of the element at
offset
.Requires
offset >= 0 && offset < count
Complexity
O(log(count
))Declaration
Swift
public func offset(of index: Index) -> Int
-
Call
body
on each element inself
in ascending order.Declaration
Swift
public func forEach(_ body: (Element) throws -> Void) rethrows
-
Return an
Array
containing the results of mapping transform overself
.Declaration
Swift
public func map<T>(_ transform: (Element) throws -> T) rethrows -> [T]
-
Return an
Array
containing the concatenated results of mappingtransform
overself
.Declaration
Swift
public func flatMap<S : Sequence>(_ transform: (Element) throws -> S) rethrows -> [S.Iterator.Element]
-
Return an
Array
containing the non-nil
results of mappingtransform
overself
.Declaration
Swift
public func flatMap<T>(_ transform: (Element) throws -> T?) rethrows -> [T]
-
Return an
Array
containing the elements ofself
, in ascending order, that satisfy the predicateincludeElement
.Declaration
Swift
public func filter(_ includeElement: (Element) throws -> Bool) rethrows -> [Element]
-
Return the result of repeatedly calling
combine
with an accumulated value initialized toinitial
and each element ofself
, in turn. I.e., returncombine(combine(...combine(combine(initial, self[0]), self[1]),...self[count-2]), self[count-1])
.Declaration
Swift
public func reduce<T>(_ initialResult: T, _ nextPartialResult: (T, Element) throws -> T) rethrows -> T
-
Return the smallest element in the set, or
nil
if the set is empty.Complexity
O(log(count
))Declaration
Swift
public var first: Element?
-
Return the largest element in the set, or
nil
if the set is empty.Complexity
O(log(count
))Declaration
Swift
public var last: Element?
-
Return the smallest element in the set, or
nil
if the set is empty.Complexity
O(log(count
))Declaration
Swift
public func min() -> Element?
-
Return the largest element in the set, or
nil
if the set is empty.Complexity
O(log(count
))Declaration
Swift
public func max() -> Element?
-
Return a copy of this set with the smallest element removed. If this set is empty, the result is an empty set.
Complexity
O(log(count
))Declaration
Swift
public func dropFirst() -> SortedSet
-
Return a copy of this set with the
n
smallest elements removed. Ifn
exceeds the number of elements in the set, the result is an empty set.Complexity
O(log(count
))Declaration
Swift
public func dropFirst(_ n: Int) -> SortedSet
-
Return a copy of this set with the largest element removed. If this set is empty, the result is an empty set.
Complexity
O(log(count
))Declaration
Swift
public func dropLast() -> SortedSet
-
Return a copy of this set with the
n
largest elements removed. Ifn
exceeds the number of elements in the set, the result is an empty set.Complexity
O(log(count
))Declaration
Swift
public func dropLast(_ n: Int) -> SortedSet
-
Returns a subset, up to
maxLength
in size, containing the smallest elements in this set.If
maxLength
exceeds the number of elements, the result contains all the elements ofself
.Complexity
O(log(count
))Declaration
Swift
public func prefix(_ maxLength: Int) -> SortedSet
-
Returns a subset containing all members of this set at or before the specified index.
Complexity
O(log(count
))Declaration
Swift
public func prefix(through index: Index) -> SortedSet
-
Returns a subset containing all members of this set less than or equal to the specified element (which may or may not be a member of this set).
Complexity
O(log(count
))Declaration
Swift
public func prefix(through element: Element) -> SortedSet
-
Returns a subset containing all members of this set before the specified index.
Complexity
O(log(count
))Declaration
Swift
public func prefix(upTo end: Index) -> SortedSet
-
Returns a subset containing all members of this set less than the specified element (which may or may not be a member of this set).
Complexity
O(log(count
))Declaration
Swift
public func prefix(upTo end: Element) -> SortedSet
-
Returns a subset, up to
maxLength
in size, containing the largest elements in this set.If
maxLength
exceedsself.count
, the result contains all the elements ofself
.Complexity
O(log(count
))Declaration
Swift
public func suffix(_ maxLength: Int) -> SortedSet
-
Returns a subset containing all members of this set at or after the specified index.
Complexity
O(log(count
))Declaration
Swift
public func suffix(from index: Index) -> SortedSet
-
Returns a subset containing all members of this set greater than or equal to the specified element (which may or may not be a member of this set).
Complexity
O(log(count
))Declaration
Swift
public func suffix(from element: Element) -> SortedSet
-
A textual representation of this set.
Declaration
Swift
public var description: String
-
A textual representation of this set, suitable for debugging.
Declaration
Swift
public var debugDescription: String
-
Return true if the set contains
element
.Complexity
O(log(count
))Declaration
Swift
public func contains(_ element: Element) -> Bool
-
Returns the index of a given member, or
nil
if the member is not present in the set.Complexity
O(log(count
))Declaration
Swift
public func index(of member: Element) -> BTreeIndex<Element, Void>?
-
Returns the index of the lowest member of this set that is strictly greater than
element
, ornil
if there is no such element.This function never returns
endIndex
. (If it returns non-nil, the returned index can be used to subscript the set.)Complexity
O(log(count
))Declaration
Swift
public func indexOfFirstElement(after element: Element) -> BTreeIndex<Element, Void>?
-
Returns the index of the lowest member of this set that is greater than or equal to
element
, ornil
if there is no such element.This function never returns
endIndex
. (If it returns non-nil, the returned index can be used to subscript the set.)Complexity
O(log(count
))Declaration
Swift
public func indexOfFirstElement(notBefore element: Element) -> BTreeIndex<Element, Void>?
-
Returns the index of the highest member of this set that is strictly less than
element
, ornil
if there is no such element.This function never returns
endIndex
. (If it returns non-nil, the returned index can be used to subscript the set.)Complexity
O(log(count
))Declaration
Swift
public func indexOfLastElement(before element: Element) -> BTreeIndex<Element, Void>?
-
Returns the index of the highest member of this set that is less than or equal to
element
, ornil
if there is no such element.This function never returns
endIndex
. (If it returns non-nil, the returned index can be used to subscript the set.)Complexity
O(log(count
))Declaration
Swift
public func indexOfLastElement(notAfter element: Element) -> BTreeIndex<Element, Void>?
-
Return
true
iffself
andother
contain the same elements.This method skips over shared subtrees when possible; this can drastically improve performance when the two sets are divergent mutations originating from the same value.
Complexity
O(count
)Declaration
Swift
public func elementsEqual(_ other: SortedSet<Element>) -> Bool
-
Returns
true
iffa
contains the same elements asb
.This function skips over shared subtrees when possible; this can drastically improve performance when the two sets are divergent mutations originating from the same value.
Complexity
O(count
)Declaration
Swift
public static func ==(a: SortedSet<Element>, b: SortedSet<Element>) -> Bool
-
Returns
true
iff no members in this set are also included inother
.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets will be simply linked into the result instead of copying, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public func isDisjoint(with other: SortedSet<Element>) -> Bool
- O(min(
-
Returns
true
iff all members in this set are also included inother
.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets will be simply linked into the result instead of copying, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public func isSubset(of other: SortedSet<Element>) -> Bool
- O(min(
-
Returns
true
iff all members in this set are also included inother
, but the two sets aren’t equal.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets may be skipped instead of elementwise processing, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public func isStrictSubset(of other: SortedSet<Element>) -> Bool
- O(min(
-
Returns
true
iff all members inother
are also included in this set.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets may be skipped instead of elementwise processing, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public func isSuperset(of other: SortedSet<Element>) -> Bool
- O(min(
-
Returns
true
iff all members inother
are also included in this set, but the two sets aren’t equal.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets may be skipped instead of elementwise processing, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public func isStrictSuperset(of other: SortedSet<Element>) -> Bool
- O(min(
-
Insert a member into the set if it is not already present.
Returns
(true, newMember)
ifnewMember
was not contained in the set. If an element equal tonewMember
was already contained in the set, the method returns(false, oldMember)
, whereoldMember
is the element that was equal tonewMember
. In some cases,oldMember
may be distinguishable fromnewMember
by identity comparison or some other means.Complexity
O(log(count
))Declaration
Swift
public mutating func insert(_ newMember: Element) -> (inserted: Bool, memberAfterInsert: Element)
Return Value
(true, newMember)
ifnewMember
was not contained in the set. If an element equal tonewMember
was already contained in the set, the method returns(false, oldMember)
, whereoldMember
is the element that was equal tonewMember
. In some cases,oldMember
may be distinguishable fromnewMember
by identity comparison or some other means. -
Inserts the given element into the set unconditionally.
If an element equal to
newMember
is already contained in the set,newMember
replaces the existing element.Parameter
Parameter newMember: An element to insert into the set.Returns
The element equal tonewMember
that was originally in the set, if exists; otherwise,nil
. In some cases, the returned element may be distinguishable fromnewMember
by identity comparison or some other means.Declaration
Swift
public mutating func update(with newMember: Element) -> Element?
Parameters
newMember
An element to insert into the set.
Return Value
The element equal to
newMember
that was originally in the set, if exists; otherwise,nil
. In some cases, the returned element may be distinguishable fromnewMember
by identity comparison or some other means.
-
Remove the member from the set and return it if it was present.
Complexity
O(log(count
))Declaration
Swift
public mutating func remove(_ element: Element) -> Element?
-
Remove the member referenced by the given index.
Complexity
O(log(count
))Declaration
Swift
public mutating func remove(at index: Index) -> Element
-
Remove the member at the given offset.
Complexity
O(log(count
))Declaration
Swift
public mutating func remove(atOffset offset: Int) -> Element
-
Remove and return the smallest member in this set, or return
nil
if the set is empty.Complexity
O(log(count
))Declaration
Swift
public mutating func popFirst() -> Element?
-
Remove and return the largest member in this set, or return
nil
if the set is empty.Complexity
O(log(count
))Declaration
Swift
public mutating func popLast() -> Element?
-
Remove all members from this set.
Declaration
Swift
public mutating func removeAll()
-
Return an
Array
containing the members of this set, in ascending order.SortedSet
already keeps its elements sorted, so this is equivalent toArray(self)
.Complexity
O(count
)Declaration
Swift
public func sorted() -> [Element]
-
Return a set containing all members in both this set and
other
.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets will be simply linked into the result instead of copying, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public func union(_ other: SortedSet<Element>) -> SortedSet<Element>
- O(min(
-
Return a set consisting of all members in
other
that are also in this set.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets will be simply linked into the result instead of copying, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public func intersection(_ other: SortedSet<Element>) -> SortedSet<Element>
- O(min(
-
Return a set consisting of members from
self
andother
that aren’t in both sets at once.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets will be simply linked into the result instead of copying, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public func symmetricDifference(_ other: SortedSet<Element>) -> SortedSet<Element>
- O(min(
-
Add all members in
other
to this set.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets will be simply linked into the result instead of copying, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public mutating func formUnion(_ other: SortedSet<Element>)
- O(min(
-
Remove all members from this set that are not included in
other
.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets will be simply linked into the result instead of copying, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public mutating func formIntersection(_ other: SortedSet<Element>)
- O(min(
-
Replace
self
with a set consisting of members fromself
andother
that aren’t in both sets at once.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets will be simply linked into the result instead of copying, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public mutating func formSymmetricDifference(_ other: SortedSet<Element>)
- O(min(
-
Return a set containing those members of this set that aren’t also included in
other
.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets will be simply linked into the result instead of copying, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public func subtracting(_ other: SortedSet) -> SortedSet
- O(min(
-
Remove all members from this set that are also included in
other
.The elements of the two input sets may be freely interleaved. However, if there are long runs of non-interleaved elements, parts of the input sets will be simply linked into the result instead of copying, which can drastically improve performance.
Complexity
- O(min(
self.count
,other.count
)) in general. - O(log(
self.count
+other.count
)) if there are only a constant amount of interleaving element runs.
Declaration
Swift
public mutating func subtract(_ other: SortedSet)
- O(min(
-
Return the count of elements in this set that are in
range
.Complexity
O(log(self.count
))Declaration
Swift
public func count(elementsIn range: Range<Element>) -> Int
-
Return the count of elements in this set that are in
range
.Complexity
O(log(self.count
))Declaration
Swift
public func count(elementsIn range: ClosedRange<Element>) -> Int
-
Return a set consisting of all members in
self
that are also inrange
.Complexity
O(log(self.count
))Declaration
Swift
public func intersection(elementsIn range: Range<Element>) -> SortedSet<Element>
-
Return a set consisting of all members in
self
that are also inrange
.Complexity
O(log(self.count
))Declaration
Swift
public func intersection(elementsIn range: ClosedRange<Element>) -> SortedSet<Element>
-
Remove all members from this set that are not included in
range
.Complexity
O(log(self.count
))Declaration
Swift
public mutating func formIntersection(elementsIn range: Range<Element>)
-
Remove all members from this set that are not included in
range
.Complexity
O(log(self.count
))Declaration
Swift
public mutating func formIntersection(elementsIn range: ClosedRange<Element>)
-
Remove all elements in
range
from this set.Complexity
O(log(self.count
))Declaration
Swift
public mutating func subtract(elementsIn range: Range<Element>)
-
Remove all elements in
range
from this set.Complexity
O(log(self.count
))Declaration
Swift
public mutating func subtract(elementsIn range: ClosedRange<Element>)
-
Return a set containing those members of this set that aren’t also included in
range
.Complexity
O(log(self.count
))Declaration
Swift
public mutating func subtracting(elementsIn range: Range<Element>) -> SortedSet<Element>
-
Return a set containing those members of this set that aren’t also included in
range
.Complexity
O(log(self.count
))Declaration
Swift
public mutating func subtracting(elementsIn range: ClosedRange<Element>) -> SortedSet<Element>
-
Shift the value of all elements starting at
start
bydelta
. For a positivedelta
, this shifts elements to the right, creating an empty gap instart ..< start + delta
. For a negativedelta
, this shifts elements to the left, removing any elements in the rangestart + delta ..< start
that were previously in the set.Complexity
O(self.count
). The elements are modified in place.Declaration
Swift
public mutating func shift(startingAt start: Element, by delta: Element.Stride)