A sequence whose elements consist of the initial consecutive elements of some base sequence that satisfy a given predicate.
SDK
- Xcode 8.3+
Framework
- Swift Standard Library
A sequence whose elements consist of the initial consecutive elements of some base sequence that satisfy a given predicate.
SDK
Framework
typealias Lazy Prefix While Sequence .Element
A type representing the sequence’s elements.
typealias Lazy Prefix While Sequence .Elements
A Sequence
that can contain the same elements as this one, possibly with a simpler type.
typealias Lazy Prefix While Sequence .Indices
A type that represents the indices that are valid for subscripting the collection, in ascending order.
typealias Lazy Prefix While Sequence .Sub Sequence
A sequence that represents a contiguous subrange of the collection’s elements.
var count: Int
The number of elements in the collection.
var elements: Lazy Prefix While Sequence<Base>
Identical to self
.
var end Index: Lazy Prefix While Sequence<Base>.Index
The collection’s “past the end” position—that is, the position one greater than the last valid subscript argument.
var first: Base .Element?
The first element of the collection.
var indices: Default Indices<Lazy Prefix While Sequence<Base>>
The indices that are valid for subscripting the collection, in ascending order.
var is Empty: Bool
A Boolean value indicating whether the collection is empty.
var last: Base .Element?
The last element of the collection.
var lazy: Lazy Sequence<Lazy Prefix While Sequence<Base>>
A sequence containing the same elements as this sequence, but on which some operations, such as map
and filter
, are implemented lazily.
var lazy: Lazy Prefix While Sequence<Base>
Identical to self
.
var start Index: Lazy Prefix While Sequence<Base>.Index
The position of the first element in a nonempty collection.
var underestimated Count: Int
A value less than or equal to the number of elements in the collection.
func all Satisfy((Base .Element) -> Bool) -> Bool
Returns a Boolean value indicating whether every element of a sequence satisfies a given predicate.
func compact Map<Element Of Result>((Base .Element) -> Element Of Result?) -> Lazy Map Sequence<Lazy Filter Sequence<Lazy Map Sequence<Lazy Prefix While Sequence<Base>, Element Of Result?>>, Element Of Result>
Returns the non-nil
results of mapping the given transformation over this sequence.
func compact Map<Element Of Result>((Base .Element) -> Element Of Result?) -> [Element Of Result]
Returns an array containing the non-nil
results of calling the given transformation with each element of this sequence.
func contains(Base .Element) -> Bool
Returns a Boolean value indicating whether the sequence contains the given element.
func contains(where: (Base .Element) -> Bool) -> Bool
Returns a Boolean value indicating whether the sequence contains an element that satisfies the given predicate.
func difference<C>(from: C) -> Collection Difference<Base .Element>
Returns the difference needed to produce this collection’s ordered elements from the given collection.
func difference<C>(from: C, by: (C .Element, Base .Element) -> Bool) -> Collection Difference<Base .Element>
Returns the difference needed to produce this collection’s ordered elements from the given collection, using the given predicate as an equivalence test.
func drop(while: (Base .Element) -> Bool) -> Lazy Drop While Sequence<Lazy Prefix While Sequence<Base>>
Returns a lazy sequence that skips any initial elements that satisfy predicate
.
func drop First(Int) -> Drop First Sequence<Lazy Prefix While Sequence<Base>>
Returns a sequence containing all but the given number of initial elements.
func drop First(Int) -> Slice<Lazy Prefix While Sequence<Base>>
Returns a subsequence containing all but the given number of initial elements.
func drop Last(Int) -> [Base .Element]
Returns a sequence containing all but the given number of final elements.
func drop Last(Int) -> Slice<Lazy Prefix While Sequence<Base>>
Returns a subsequence containing all but the specified number of final elements.
func elements Equal<Other Sequence>(Other Sequence) -> Bool
Returns a Boolean value indicating whether this sequence and another sequence contain the same elements in the same order.
func elements Equal<Other Sequence>(Other Sequence, by: (Base .Element, Other Sequence .Element) -> Bool) -> Bool
Returns a Boolean value indicating whether this sequence and another sequence contain equivalent elements in the same order, using the given predicate as the equivalence test.
func enumerated() -> Enumerated Sequence<Lazy Prefix While Sequence<Base>>
Returns a sequence of pairs (n, x), where n represents a consecutive integer starting at zero and x represents an element of the sequence.
func filter((Base .Element) -> Bool) -> Lazy Filter Sequence<Lazy Prefix While Sequence<Base>>
Returns the elements of self
that satisfy is
.
func first(where: (Base .Element) -> Bool) -> Base .Element?
Returns the first element of the sequence that satisfies the given predicate.
func first Index(of: Base .Element) -> Lazy Prefix While Sequence<Base>.Index?
Returns the first index where the specified value appears in the collection.
func first Index(where: (Base .Element) -> Bool) -> Lazy Prefix While Sequence<Base>.Index?
Returns the first index in which an element of the collection satisfies the given predicate.
func flat Map<Segment Of Result>((Base .Element) -> Segment Of Result) -> Lazy Sequence<Flatten Sequence<Lazy Map Sequence<Lazy Prefix While Sequence<Base>, Segment Of Result>>>
Returns the concatenated results of mapping the given transformation over this sequence.
func flat Map<Element Of Result>((Base .Element) -> Element Of Result?) -> Lazy Map Sequence<Lazy Filter Sequence<Lazy Map Sequence<Lazy Prefix While Sequence<Base>, Element Of Result?>>, Element Of Result>
Returns the non-nil
results of mapping the given transformation over this sequence.
func flat Map<Segment Of Result>((Base .Element) -> Segment Of Result) -> [Segment Of Result .Element]
Returns an array containing the concatenated results of calling the given transformation with each element of this sequence.
func flat Map<Element Of Result>((Base .Element) -> Element Of Result?) -> [Element Of Result]
Returns an array containing the non-nil
results of calling the given transformation with each element of this sequence.
func for Each((Base .Element) -> Void)
Calls the given closure on each element in the sequence in the same order as a for
-in
loop.
func form Index(inout Lazy Prefix While Sequence<Base>.Index, offset By: Int)
Offsets the given index by the specified distance.
func form Index(inout Lazy Prefix While Sequence<Base>.Index, offset By: Int, limited By: Lazy Prefix While Sequence<Base>.Index) -> Bool
Offsets the given index by the specified distance, or so that it equals the given limiting index.
func form Index(after: inout Lazy Prefix While Sequence<Base>.Index)
Replaces the given index with its successor.
func form Index(before: inout Lazy Prefix While Sequence<Base>.Index)
Replaces the given index with its predecessor.
func index(after: Lazy Prefix While Sequence<Base>.Index) -> Lazy Prefix While Sequence<Base>.Index
Returns the position immediately after the given index.
func index(before: Lazy Prefix While Sequence<Base>.Index) -> Lazy Prefix While Sequence<Base>.Index
Returns the position immediately before the given index.
func index(of: Base .Element) -> Lazy Prefix While Sequence<Base>.Index?
Returns the first index where the specified value appears in the collection.
func index(where: (Base .Element) -> Bool) -> Lazy Prefix While Sequence<Base>.Index?
Returns the first index in which an element of the collection satisfies the given predicate.
func joined() -> Lazy Sequence<Flatten Sequence<Lazy Prefix While Sequence<Base>>>
Returns a lazy sequence that concatenates the elements of this sequence of sequences.
func joined() -> Flatten Sequence<Lazy Prefix While Sequence<Base>>
Returns the elements of this sequence of sequences, concatenated.
func joined(separator: String) -> String
Returns a new string by concatenating the elements of the sequence, adding the given separator between each element.
func joined<Separator>(separator: Separator) -> Joined Sequence<Lazy Prefix While Sequence<Base>>
Returns the concatenated elements of this sequence of sequences, inserting the given separator between each element.
func joined(separator: String) -> String
Returns a new string by concatenating the elements of the sequence, adding the given separator between each element.
func last(where: (Base .Element) -> Bool) -> Base .Element?
Returns the last element of the sequence that satisfies the given predicate.
func last Index(of: Base .Element) -> Lazy Prefix While Sequence<Base>.Index?
Returns the last index where the specified value appears in the collection.
func last Index(where: (Base .Element) -> Bool) -> Lazy Prefix While Sequence<Base>.Index?
Returns the index of the last element in the collection that matches the given predicate.
func lexicographically Precedes<Other Sequence>(Other Sequence) -> Bool
Returns a Boolean value indicating whether the sequence precedes another sequence in a lexicographical (dictionary) ordering, using the less-than operator (<
) to compare elements.
func lexicographically Precedes<Other Sequence>(Other Sequence, by: (Base .Element, Base .Element) -> Bool) -> Bool
Returns a Boolean value indicating whether the sequence precedes another sequence in a lexicographical (dictionary) ordering, using the given predicate to compare elements.
func make Iterator() -> Lazy Prefix While Sequence<Base>.Iterator
Returns an iterator over the elements of this sequence.
func map<U>((Base .Element) -> U) -> Lazy Map Sequence<Lazy Prefix While Sequence<Base>, U>
Returns a Lazy
over this Sequence
. The elements of the result are computed lazily, each time they are read, by calling transform
function on a base element.
func map<T>((Base .Element) -> T) -> [T]
Returns an array containing the results of mapping the given closure over the sequence’s elements.
func map<T>((Base .Element) -> T) -> [T]
Returns an array containing the results of mapping the given closure over the sequence’s elements.
func max() -> Base .Element?
Returns the maximum element in the sequence.
func max(by: (Base .Element, Base .Element) -> Bool) -> Base .Element?
Returns the maximum element in the sequence, using the given predicate as the comparison between elements.
func min() -> Base .Element?
Returns the minimum element in the sequence.
func min(by: (Base .Element, Base .Element) -> Bool) -> Base .Element?
Returns the minimum element in the sequence, using the given predicate as the comparison between elements.
func prefix(Int) -> Prefix Sequence<Lazy Prefix While Sequence<Base>>
Returns a sequence, up to the specified maximum length, containing the initial elements of the sequence.
func prefix(Int) -> Slice<Lazy Prefix While Sequence<Base>>
Returns a subsequence, up to the specified maximum length, containing the initial elements of the collection.
func prefix(through: Lazy Prefix While Sequence<Base>.Index) -> Slice<Lazy Prefix While Sequence<Base>>
Returns a subsequence from the start of the collection through the specified position.
func prefix(up To: Lazy Prefix While Sequence<Base>.Index) -> Slice<Lazy Prefix While Sequence<Base>>
Returns a subsequence from the start of the collection up to, but not including, the specified position.
func prefix(while: (Base .Element) -> Bool) -> Lazy Prefix While Sequence<Lazy Prefix While Sequence<Base>>
Returns a lazy sequence of the initial consecutive elements that satisfy predicate
.
func random Element() -> Base .Element?
Returns a random element of the collection.
func random Element<T>(using: inout T) -> Base .Element?
Returns a random element of the collection, using the given generator as a source for randomness.
func reduce<Result>(Result, (Result, Base .Element) -> Result) -> Result
Returns the result of combining the elements of the sequence using the given closure.
func reduce<Result>(into: Result, (inout Result, Base .Element) -> ()) -> Result
Returns the result of combining the elements of the sequence using the given closure.
func reversed() -> [Base .Element]
Returns an array containing the elements of this sequence in reverse order.
func shuffled() -> [Base .Element]
Returns the elements of the sequence, shuffled.
func shuffled<T>(using: inout T) -> [Base .Element]
Returns the elements of the sequence, shuffled using the given generator as a source for randomness.
func sorted() -> [Base .Element]
Returns the elements of the sequence, sorted.
func sorted(by: (Base .Element, Base .Element) -> Bool) -> [Base .Element]
Returns the elements of the sequence, sorted using the given predicate as the comparison between elements.
func split(max Splits: Int, omitting Empty Subsequences: Bool, where Separator: (Base .Element) -> Bool) -> [Array Slice<Base .Element>]
Returns the longest possible subsequences of the sequence, in order, that don’t contain elements satisfying the given predicate. Elements that are used to split the sequence are not returned as part of any subsequence.
func split(max Splits: Int, omitting Empty Subsequences: Bool, where Separator: (Base .Element) -> Bool) -> [Slice<Lazy Prefix While Sequence<Base>>]
Returns the longest possible subsequences of the collection, in order, that don’t contain elements satisfying the given predicate.
func split(separator: Base .Element, max Splits: Int, omitting Empty Subsequences: Bool) -> [Array Slice<Base .Element>]
Returns the longest possible subsequences of the sequence, in order, around elements equal to the given element.
func split(separator: Base .Element, max Splits: Int, omitting Empty Subsequences: Bool) -> [Slice<Lazy Prefix While Sequence<Base>>]
Returns the longest possible subsequences of the collection, in order, around elements equal to the given element.
func starts<Possible Prefix>(with: Possible Prefix) -> Bool
Returns a Boolean value indicating whether the initial elements of the sequence are the same as the elements in another sequence.
func starts<Possible Prefix>(with: Possible Prefix, by: (Base .Element, Possible Prefix .Element) -> Bool) -> Bool
Returns a Boolean value indicating whether the initial elements of the sequence are equivalent to the elements in another sequence, using the given predicate as the equivalence test.
func suffix(Int) -> [Base .Element]
Returns a subsequence, up to the given maximum length, containing the final elements of the sequence.
func suffix(Int) -> Slice<Lazy Prefix While Sequence<Base>>
Returns a subsequence, up to the given maximum length, containing the final elements of the collection.
func suffix(from: Lazy Prefix While Sequence<Base>.Index) -> Slice<Lazy Prefix While Sequence<Base>>
Returns a subsequence from the specified position to the end of the collection.
func with Contiguous Storage If Available<R>((Unsafe Buffer Pointer<Base .Element>) -> R) -> R?
Call body(p)
, where p
is a pointer to the collection’s contiguous storage. If no such storage exists, it is first created. If the collection does not support an internal representation in a form of contiguous storage, body
is not called and nil
is returned.
subscript<R>(R) -> Slice<Lazy Prefix While Sequence<Base>>
Accesses the contiguous subrange of the collection’s elements specified by a range expression.
subscript(Range<Lazy Prefix While Sequence<Base>.Index>) -> Slice<Lazy Prefix While Sequence<Base>>
Accesses a contiguous subrange of the collection’s elements.
subscript(Lazy Prefix While Sequence<Base>.Index) -> Lazy Prefix While Sequence<Base>.Element
Accesses the element at the specified position.
struct Lazy Prefix While Sequence .Index
A position in a Lazy
or Lazy
instance.
struct Lazy Prefix While Sequence .Iterator
An iterator over the initial elements traversed by a base iterator that satisfy a given predicate.
struct Lazy Sequence
A sequence containing the same elements as a Base
sequence, but on which some operations such as map
and filter
are implemented lazily.
struct Lazy Map Sequence
A Sequence
whose elements consist of those in a Base
Sequence
passed through a transform function returning Element
. These elements are computed lazily, each time they’re read, by calling the transform function on a base element.
struct Lazy Filter Sequence
A sequence whose elements consist of the elements of some base sequence that also satisfy a given predicate.
struct Lazy Drop While Sequence
A sequence whose elements consist of the elements that follow the initial consecutive elements of some base sequence that satisfy a given predicate.
typealias Lazy Collection
A collection containing the same elements as a Base
collection, but on which some operations such as map
and filter
are implemented lazily.
typealias Lazy Drop While Collection
A lazy wrapper that includes the elements of an underlying collection after any initial consecutive elements that satisfy a predicate.
typealias Lazy Filter Collection
A lazy Collection
wrapper that includes the elements of an underlying collection that satisfy a predicate.
typealias Lazy Map Collection
A Collection
whose elements consist of those in a Base
Collection
passed through a transform function returning Element
. These elements are computed lazily, each time they’re read, by calling the transform function on a base element.
typealias Lazy Prefix While Collection
A lazy ${Collection}
wrapper that includes the initial consecutive elements of an underlying collection that satisfy a predicate.