Bimap

public struct Bimap<Key: Hashable, Value: Hashable>

A Bimap is a special kind of dictionary that allows bidirectional lookup between keys and values. All keys and values must be unique. It allows to get, set, or delete a key-value pairs using subscript notation: bimap[value: aValue] = aKey or bimap[key: aKey] = aValue

Conforms to Sequence, Collection, ExpressibleByDictionaryLiteral, Equatable, Hashable and CustomStringConvertible.

Creating a Bimap

  • Constructs an empty bimap.

    Declaration

    Swift

    public init()

  • Constructs a bimap with at least the given number of elements worth of storage. The actual capacity will be the smallest power of 2 that’s >= minimumCapacity.

    Declaration

    Swift

    public init(minimumCapacity: Int)

  • Constructs a bimap from a dictionary.

    Declaration

    Swift

    public init(_ elements: Dictionary<Key, Value>)

  • Constructs a bimap from a sequence of key-value pairs.

    Declaration

    Swift

    public init<S:Sequence>(_ elements: S) where S.Iterator.Element == (Key, Value)

Querying a Bimap

  • Number of key-value pairs stored in the bimap.

    Declaration

    Swift

    public var count: Int

  • Returns true if and only if count == 0.

    Declaration

    Swift

    public var isEmpty: Bool

  • A collection containing all the bimap’s keys.

    Declaration

    Swift

    public var keys: AnyCollection<Key>

  • A collection containing all the bimap’s values.

    Declaration

    Swift

    public var values: AnyCollection<Value>

Accessing and Changing Bimap Elements

  • Inserts or updates a value for a given key and returns the previous value for that key if one existed, or nil if a previous value did not exist. Subscript access is preferred.

    Declaration

    Swift

    public mutating func updateValue(_ value: Value, forKey key: Key) -> Value?

  • Removes the key-value pair for the given key and returns its value, or nil if a value for that key did not previously exist. Subscript access is preferred.

    Declaration

    Swift

    public mutating func removeValueForKey(_ key: Key) -> Value?

  • Removes the key-value pair for the given value and returns its key, or nil if a key for that value did not previously exist. Subscript access is preferred.

    Declaration

    Swift

    public mutating func removeKeyForValue(_ value: Value) -> Key?

  • Removes all the elements from the bimap, and by default clears the underlying storage buffer.

    Declaration

    Swift

    public mutating func removeAll(keepCapacity keep: Bool = true)

Sequence Protocol Conformance

  • Provides for-in loop functionality.

    Declaration

    Swift

    public func makeIterator() -> DictionaryIterator<Key, Value>

    Return Value

    A generator over the elements.

Collection Protocol Conformance

  • The position of the first element in a non-empty bimap.

    Identical to endIndex in an empty bimap

    Complexity: amortized O(1)

    Declaration

    Swift

    public var startIndex: DictionaryIndex<Key, Value>

  • The collection’s past the end position.

    endIndex is not a valid argument to subscript, and is always reachable from startIndex by zero or more applications of successor().

    Complexity: amortized O(1)

    Declaration

    Swift

    public var endIndex: DictionaryIndex<Key, Value>

  • Returns the position immediately after the given index.

    Parameter

    Parameter i: A valid index of the collection. i must be less than endIndex.

    Returns

    The index value immediately after i.

    Declaration

    Swift

    public func index(after i: DictionaryIndex<Key, Value>) -> DictionaryIndex<Key, Value>

    Parameters

    i

    A valid index of the collection. i must be less than endIndex.

    Return Value

    The index value immediately after i.

ExpressibleByDictionaryLiteral Protocol Conformance

  • Constructs a bimap using a dictionary literal.

    Declaration

    Swift

    public init(dictionaryLiteral elements: (Key, Value)...)

CustomStringConvertible Protocol Conformance

  • A string containing a suitable textual representation of the bimap.

    Declaration

    Swift

    public var description: String

Hashable Protocol Conformance

  • The hash value. x == y implies x.hashValue == y.hashValue

    Declaration

    Swift

    public var hashValue: Int