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EventSource class

An event source extends the immutable Events interface with functions that support imperative input.

Synopsis

template
<
    typename D,
    typename E = Token
>
class EventSource : public Events<D,E>
{
public:
    // Constructor
    EventSource();
    EventSource(const EventSource&);    // Copy
    EventSource(EventSource&&);         // Move

    // Assignemnt
    EventSource& operator=(const EventSource&);     // Copy
    EventSource& operator=(EventSource&& other);    // Move

    // Emits an event
    void Emit(const E& e) const;
    void Emit(E&& e) const;
    void Emit() const;

    // Function operator version of `Emit`
    void operator()(const E& e) const;
    void operator()(E&& e) const;
    void operator()() const;

    // Stream operator version of `Emit`
    const EventSource& operator<<(const E& e) const;
    const EventSource& operator<<(E&& e) const;
};

Constructor, operator= member function

Analogously defined to Events.

Emit, operator() member function

Syntax

void Emit(const E& e) const;        // (1)
void Emit(E&& e) const;             // (2)
void Emit() const;                  // (3)

void operator()(const E& e) const;  // (1)
void operator()(E&& e) const;       // (2)
void operator() const;              // (3)

Semantics

Adds e to the queue of outgoing events of the linked event source node.

If Emit was called inside of a transaction function, it will return after the event has been queued and propagation is delayed until the transaction function returns. Otherwise, propagation starts immediately and Emit blocks until it’s done.

Using operator() is semantically equivalent to Emit.

(1) and (2) take an event value argument; (3) allows to omit that for token streams, where the emitted value is always token.

operator<< member function

Syntax

const EventSource& operator<<(const E& e) const;
const EventSource& operator<<(E&& e) const;

Semantics

Semantically equivalent to Emit. In particular, chaining multiple events in a single statement will not execute them in a single transaction.