Typinformation

Typinformation refers to metadata that describes the type of a value or object within a programming language or runtime system. It includes information that may be available statically at compile time as well as information that exists at runtime. The content of typinformation typically covers the kind of the type (primitive, class, interface, array, etc.), its name, its size in memory, its place in the type hierarchy, and the members or operations associated with it (methods, fields, generics, etc.). In many runtimes, typinformation is stored in dedicated structures such as type descriptors, class objects, or vtables, and is used by tooling and libraries as well as by the language runtime itself.

Common purposes of typinformation include reflection and introspection, serialization and deserialization, dynamic dispatch, type checking, and debugging. Reflection allows a program to examine and sometimes instantiate types that are not known at compile time, while serialization relies on type metadata to convert objects to and from a portable form. In statically typed languages, some typinformation is available only at compile time, whereas in languages with run-time type information, it is accessible during program execution.

Examples across languages illustrate different approaches. Java exposes typinformation through Class objects and the reflection API; C++ provides RTTI through typeid and dynamic_cast; C# uses System.Type for reflection; Go exposes reflect.Type; Python exposes runtime type objects via type() and __class__; TypeScript, by contrast, erases most type information at runtime. Rust and Haskell have approaches to type information that are more restricted or provided through specific type- and trait-system mechanisms.

Overall, typinformation is a foundational concept enabling dynamic behavior, tooling support, and interoperability in modern programming environments.