reactivitywithout

Reactivitywithout is a concept in reactive programming that describes achieving automatic reactivity without requiring developers to write explicit subscriptions or event listeners. In a reactivitywithout approach, program state and computations declare dependencies by performing reads on a shared data model. The system records these reads to construct an internal dependency graph; when a piece of state changes, the runtime propagates updates through the graph to recompute only the affected values and re-render dependent views. This can be implemented with language features such as proxies or getters, or with data structures that support incremental change tracking and structural sharing.

Key ideas include automatic dependency tracking, incremental recomputation, and composable computations forming an effect graph. Benefits include reduced boilerplate, simpler reasoning about data flow, and the potential for fine-grained updates that minimize work. Limitations include debugging difficulty, the risk of hidden costs from broad dependencies, potential memory overhead, and the need for careful design to avoid cycles.

Origin and usage: The term is used in discussions of modern UI architectures and research into incremental computation. It describes a departure from explicit observer registration toward implicit dependency tracking and automatic propagation. Examples are primarily in experimental libraries and prototype frameworks, often within academic or hobbyist projects, where authors compare reactivitywithout to traditional reactive patterns.

See also: reactive programming; incremental computation; dataflow programming.