ProtocolSwift

BidirectionalCollection

A collection that supports backward as well as forward traversal.

protocol BidirectionalCollection<Element> : Collection where Self.Indices : BidirectionalCollection, Self.SubSequence : BidirectionalCollection

Overview

Bidirectional collections offer traversal backward from any valid index, not including a collection’s startIndex. Bidirectional collections can therefore offer additional operations, such as a last property that provides efficient access to the last element and a reversed() method that presents the elements in reverse order. In addition, bidirectional collections have more efficient implementations of some sequence and collection methods, such as suffix(_:).

Conforming to the BidirectionalCollection Protocol

To add BidirectionalProtocol conformance to your custom types, implement the index(before:) method in addition to the requirements of the Collection protocol.

Indices that are moved forward and backward in a bidirectional collection move by the same amount in each direction. That is, for any valid index i into a bidirectional collection c:

If i >= c.startIndex && i < c.endIndex, then c.index(before: c.index(after: i)) == i.
If i > c.startIndex && i <= c.endIndex, then c.index(after: c.index(before: i)) == i.

Valid indices are exactly those indices that are reachable from the collection’s startIndex by repeated applications of index(after:), up to, and including, the endIndex.

Requirements

Associated Types

Instance Subscripts

subscript(Range<Self.Index>) -> Self.SubSequence
Accesses a contiguous subrange of the collection’s elements.
subscript(Self.Index) -> Self.Element

Instance Properties

var endIndex: Self.Index
var indices: Self.Indices
The indices that are valid for subscripting the collection, in ascending order.
var startIndex: Self.Index

Instance Methods

func distance(from: Self.Index, to: Self.Index) -> Int
Returns the distance between two indices.
func formIndex(after: inout Self.Index)
Replaces the given index with its successor.
func formIndex(before: inout Self.Index)
Replaces the given index with its predecessor.
func index(Self.Index, offsetBy: Int) -> Self.Index
Returns an index that is the specified distance from the given index.
func index(Self.Index, offsetBy: Int, limitedBy: Self.Index) -> Self.Index?
Returns an index that is the specified distance from the given index, unless that distance is beyond a given limiting index.
func index(after: Self.Index) -> Self.Index
Returns the position immediately after the given index.
func index(before: Self.Index) -> Self.Index
Returns the position immediately before the given index.

Members

Instance Properties

var last: Self.Element?
The last element of the collection.

Instance Methods

func difference<C>(from: C) -> CollectionDifference<Self.Element>
Returns the difference needed to produce this collection’s ordered elements from the given collection.
func difference<C>(from: C, by: (C.Element, Self.Element) -> Bool) -> CollectionDifference<Self.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 dropLast(Int) -> Self.SubSequence
Returns a subsequence containing all but the specified number of final elements.
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: (Self.Element) throws -> Bool) rethrows -> Self.Element?
Returns the last element of the sequence that satisfies the given predicate.
func lastIndex(of: Self.Element) -> Self.Index?
Returns the last index where the specified value appears in the collection.
func lastIndex(where: (Self.Element) throws -> Bool) rethrows -> Self.Index?
Returns the index of the last element in the collection that matches the given predicate.
func popLast() -> Self.Element?
Removes and returns the last element of the collection.
func removeLast() -> Self.Element
Removes and returns the last element of the collection.
func removeLast(Int)
Removes the given number of elements from the end of the collection.
func reversed() -> ReversedCollection<Self>
Returns a view presenting the elements of the collection in reverse order.
func suffix(Int) -> Self.SubSequence
Returns a subsequence, up to the given maximum length, containing the final elements of the collection.

RegexBuilder

func contains(() -> some RegexComponent) -> Bool
Returns a Boolean value indicating whether this collection contains a match for the regex, where the regex is created by the given closure.
func firstMatch<Output>(of: () -> some RegexComponent) -> Regex<Output>.Match?
Returns the first match for the regex within this collection, where the regex is created by the given closure.
func firstRange(of: () -> some RegexComponent) -> Range<Self.Index>?
Returns the range of the first match for the regex within this collection, where the regex is created by the given closure.
func matches<Output>(of: () -> some RegexComponent) -> [Regex<Output>.Match]
Returns a collection containing all non-overlapping matches of the regex, created by the given closure.
func prefixMatch<Output>(of: () -> some RegexComponent) -> Regex<Output>.Match?
Matches part of the regex, starting at the beginning, where the regex is created by the given closure.
func ranges(of: () -> some RegexComponent) -> [Range<Self.Index>]
Returns the ranges of the all non-overlapping matches for the regex within this collection, where the regex is created by the given closure.
func split(maxSplits: Int, omittingEmptySubsequences: Bool, separator: () -> some RegexComponent) -> [Self.SubSequence]
Returns the longest possible subsequences of the collection, in order, around subsequence that match the regex created by the given closure.
func starts(with: () -> some RegexComponent) -> Bool
Returns a Boolean value indicating whether the initial elements of this collection are a match for the regex created by the given closure.
func trimmingPrefix(() -> some RegexComponent) -> Self.SubSequence
Returns a subsequence of this collection by removing the elements matching the regex from the start, where the regex is created by the given closure.
func wholeMatch<Output>(of: () -> some RegexComponent) -> Regex<Output>.Match?
Matches a regex in its entirety, where the regex is created by the given closure.

RegexParser

StringProcessing

func contains(some RegexComponent) -> Bool
Returns a Boolean value indicating whether the collection contains the given regex.
func firstMatch<Output>(of: some RegexComponent) -> Regex<Output>.Match?
Returns the first match of the specified regex within the collection.
func firstRange(of: some RegexComponent) -> Range<Self.Index>?
Finds and returns the range of the first occurrence of a given regex within the collection.
func firstRange<C>(of: C) -> Range<Self.Index>?
Finds and returns the range of the first occurrence of a given collection within this collection.
func matches<Output>(of: some RegexComponent) -> [Regex<Output>.Match]
Returns a collection containing all matches of the specified regex.
func prefixMatch<R>(of: R) -> Regex<R.RegexOutput>.Match?
Checks for a match against the string, starting at its beginning.
func ranges(of: some RegexComponent) -> [Range<Self.Index>]
Finds and returns the ranges of the all occurrences of a given sequence within the collection.
func split(separator: some RegexComponent, maxSplits: Int, omittingEmptySubsequences: Bool) -> [Self.SubSequence]
Returns the longest possible subsequences of the collection, in order, around elements equal to the given separator.
func starts(with: some RegexComponent) -> Bool
Returns a Boolean value indicating whether the initial elements of the sequence are the same as the elements in the specified regex.
func trimmingPrefix(some RegexComponent) -> Self.SubSequence
Returns a new collection of the same type by removing prefix from the start.
func wholeMatch<R>(of: R) -> Regex<R.RegexOutput>.Match?
Checks for a match against the string in its entirety.

Algorithms

func suffix(while: (Self.Element) throws -> Bool) rethrows -> Self.SubSequence
Returns a subsequence containing the elements from the end until predicate returns false and skipping the remaining elements.
func trim(while: (Self.Element) throws -> Bool) rethrows
Mutates a BidirectionalCollection by discarding all elements at the start and at the end of it which satisfy the given predicate.
func trim(while: (Self.Element) throws -> Bool) rethrows
Mutates a BidirectionalCollection by discarding all elements at the start and at the end of it which satisfy the given predicate.
func trimSuffix(while: (Self.Element) throws -> Bool) rethrows
Mutates a BidirectionalCollection by discarding all elements at the end of it which satisfy the given predicate.
func trimSuffix(while: (Self.Element) throws -> Bool) rethrows
Mutates a BidirectionalCollection by discarding all elements at the end of it which satisfy the given predicate.
func trimming(while: (Self.Element) throws -> Bool) rethrows -> Self.SubSequence
Returns a SubSequence formed by discarding all elements at the start and end of the collection which satisfy the given predicate.
func trimmingSuffix(while: (Self.Element) throws -> Bool) rethrows -> Self.SubSequence
Returns a SubSequence formed by discarding all elements at the end of the collection which satisfy the given predicate.

BidirectionalCollection

Overview

Conforming to the BidirectionalCollection Protocol

Refinements

Requirements

Associated Types

Instance Subscripts

Instance Properties

Instance Methods

Members

Instance Properties

Instance Methods

Conforming Types

Implies