ReplayLastSubjectType

public struct ReplayLastSubjectType<Element, ErrorType> where ErrorType : Error

Abstraction over subject types able to keep the last object (CurrentValueSubject, BehaviorSubject, MutableProperty, Variable) from reactive frameworks. This abstraction uses concept similar to type-erasure or protocol witness pattern, wrapping the behaviour of concrete implementations and delegating to them once the wrapper funcions are called.

publisher
Upstream publisher that feeds data into this subject
Declaration
Swift

public let publisher: PublisherType<Element, ErrorType>
subscriber
Downstream subscriber that subscribes to this subject and will receive events from it
Declaration
Swift

public let subscriber: SubscriberType<Element, ErrorType>
value
Reads the most recent element emitted by this subject. This subject can be seen as a variable in stateful programming style, it holds one value that can be read at any point using a getter function () -> Element. Useful for bridging with the imperative world.
Declaration
Swift

public var value: () -> Element


                    
                    
                    init(publisher:subscriber:value:)

Creates an abstraction over subject types able to keep the last object (CurrentValueSubject, BehaviorSubject, MutableProperty, Variable) from reactive frameworks.

Declaration

Swift

public init(
    publisher: PublisherType<Element, ErrorType>,
    subscriber: SubscriberType<Element, ErrorType>,
    value: @escaping () -> Element)

Parameters

`publisher`	Upstream publisher that feeds events into this subject
`subscriber`	Downstream subscriber that subscribes to this subject and will receive events from it
`value`	Reads the most recent element emitted by this subject. This subject can be seen as a variable in stateful programming style, it holds one value that can be read at any point using a getter function `() -> Element`. Useful for bridging with the imperative world.


                    
                    
                    mutate(_:)

Atomically mutate this subject’s value in a closure where you can read and write the current element value

Declaration

Swift

@discardableResult
public func mutate<Result>(_ action: (inout Element) -> Result) -> Result

Parameters


                                action

read and write the current value atomically, and optionally return something

Return Value

returns whatever is returned by the action closure, allowing to chain operations


                    
                    
                    mutate(when:action:)

Atomically mutate this subject’s value in a closure where you can read and write the current element value Before the mutation, a condition will be evaluated and the mutation will only happen when the result of this evaluation returns true. This allows you to simulate the mutation before executing it.

Declaration

Swift

@discardableResult
public func mutate<Result>(when condition: @escaping (Result) -> Bool, action: (inout Element) -> Result) -> Result

Parameters

`condition`	a predicate that, after simulating the mutation, allows you to decide if it should happen or not
`action`	read and write the current value atomically, and optionally return something

Return Value

returns whatever is returned by the action closure, allowing to chain operations