reactivitywhile

Reactivitywhile is a concept in reactive programming describing a pattern in which a computation remains active and updates its outputs as long as a controlling condition is true. The term is not tied to a single language, but appears in discussions of dataflow and signal-based programming to capture a guarded reactive loop.

Semantics: Inputs are treated as signals, and the system re-evaluates the body whenever dependent signals change, provided the guard condition cond is true. If cond becomes false, the reactive computation is deactivated and resources, listeners, or subscriptions associated with the loop are released. Termination is achieved when the guard flips to false or when the reactive block is explicitly destroyed.

Example (conceptual): while cond do output := f(input) end

Applications: Reactive systems use reactivitywhile in streaming data pipelines, interactive user interfaces, and simulations where continuous updates are desired only while a condition holds.

Relation to other concepts: It relates to guard-based execution, fixpoint iteration, and signal-based reactivity. It differs from traditional imperative while loops by relying on the runtime to manage reactivity, dependencies, and teardown rather than explicit iteration.

Limitations: Implementations must handle edge cases such as cycles, memory leaks from lingering observers, and termination guarantees. Correct propagation of guard changes is essential to avoid unnecessary updates or runaway computations.

See also: reactive programming, reactive signals, dataflow programming, while loop, guard condition, teardown.