Rtypes

Rtypes is a conceptual framework and set of language constructs for describing and enforcing runtime types in programming environments. It provides a separate layer of type metadata that accompanies values at runtime, enabling explicit checks, validation, and contract enforcement without relying solely on static type systems.

Definition and scope: An Rtype is a descriptor that encodes a type’s structure and semantics, including primitives (for example, Int, String), composites (Array<T>, Map<K,V>), and functional types. Each descriptor may include constraints such as ranges, predicates, or user-defined invariants. A type registry stores descriptors and offers services such as validation, coercion, and pretty-printing.

Core concepts: Type descriptors, type tags, and meta-objects; validation and coercion rules; subtyping and distinctions between nominal and structural relations; support for generics or parametric types; reflection and inspection; serialization and deserialization across boundaries; and contracts for remote interactions.

Architecture: Values carry a type descriptor that can be inspected at runtime. A runtime checker uses the descriptor to validate or coerce values. A registry may be global or modular, allowing libraries to extend the set of available types. Optional static hints can aid optimization, but enforcement remains at runtime.

Use cases: Enforcing data contracts in APIs, validating user input, safe inter-process or network communication, dynamic loading of plugins, debugging and introspection, and serialization formats that require schemas.

History and relationship to other concepts: The approach integrates with existing type systems by supplementing them with runtime type information, balancing flexibility with safety in dynamic contexts. See also runtime type information, data validation, reflection, and serialization.