moduledefined

Moduledefined is a concept in software modularity describing a module whose public interface is defined independently from its implementation. In a moduledefined design, a module exposes a contract—often captured in a formal interface or signature—that specifies the names, types, and behavioral invariants of its exports, while the underlying code provides the implementation that satisfies the contract. The separation between interface and implementation supports independent development, verification, and replacement of components.

A moduledefined system typically includes two artifacts: the interface, which may include type signatures, preconditions, postconditions, and dependency constraints; and the implementation, which provides the actual code and internal state. The binding between interface and implementation is governed by a module loader or compiler that checks compatibility and enforces constraints, enabling safer composition of modules and easier reasoning about system behavior. In dynamic environments, moduledefined modules can be swapped at runtime as long as the new implementation adheres to the same interface.

Relation and history: The idea aligns with interface-based programming, abstract data types, and modern module systems that separate specification from implementation. It appears in discussions of plugin architectures, component-based software engineering, and formal methods for modular verification. While not a single standardized technology, moduledefined serves as a conceptual goal across languages that support explicit interfaces, signatures, or type classes.

See also: interface, module system, abstract data type, plugin architecture, formal verification.