cueB

cueB is a software framework designed to coordinate asynchronous tasks through cue-based event orchestration. It provides a minimal vocabulary of cues—signals that mark points of interest in a workflow—and a runtime that enables tasks to emit, listen for, and compose these cues in a predictable manner. The goal of cueB is to simplify complex asynchronous flows by replacing ad hoc callback chains with explicit, testable cue dependencies.

Core concepts include: a cue, which represents a single event or condition; a cue set, a collection of related cues; and combinators, such as race, all, and then, that describe how multiple cues interact. A listener can await a cue or a set, with optional timeouts and error handling. Cues can be bound to I/O, timers, user input, or inter-thread messages, allowing cross-boundary coordination without deep coupling.

Design and implementation: cueB is language-agnostic in its specification, with reference implementations in several languages and bindable adapters for different runtimes. The framework emphasizes deterministic ordering, observability, and graceful degradation under backpressure. It supports serializing cue state for distributed execution and integrating with existing event loops or task schedulers.

History: cueB originated in collaborative open-source projects in the early 2010s, aiming to standardize cue-based workflows. It has seen incremental adoption in interactive media, automation, and research settings, with varying levels of community support depending on the platform.

Usage and reception: proponents cite improved readability and testability of asynchronous code, while critics note initial learning overhead and potential performance costs for simple tasks. Alternatives include promise-based and reactive programming models.

See also: event-driven programming, asynchronous communication, futures, promises, reactive streams.