Cospecui

Cospecui is a term used in software engineering to describe a design principle and tooling approach that aims to co-specify two or more related aspects of a software system, typically the user interface (UI) and the underlying data model or domain logic. The name is a contraction of co-specification for UI, reflecting the idea of a single, unified specification that governs multiple components.

Definition and core ideas: In cospecui, developers create a joint specification that includes UI layout, behavior, data structures, validation rules, and derived properties. The framework or methodology facilitates bidirectional synchronization between the UI and the model, ensuring that changes in one representation are reflected in the other. This can reduce drift between layers, enable consistency checks, propagate constraints, and support automated UI generation from models.

History and usage: The term has appeared in academic and industry literature since the 2010s, though it is not widely standardized. Variants exist that emphasize strong coupling with a single source of truth, while others support transformation-based synchronization with explicit rules. Some discussions position cospecui alongside model-driven engineering and bidirectional programming paradigms.

Applications and challenges: Potential domains include form-heavy enterprise applications, data-entry systems, and editors for domain-specific languages, where consistency between UI and data is critical. Challenges include expressive power, learning curves, tooling maturity, potential performance overhead, and balancing automation with developer control.

See also: bidirectional transformations, lenses, model-driven engineering, reactive programming.