Type Safe Metadata Combining

Abstract

Type safety is an important property of any type system. Modern programming languages support different mechanisms to work in type safe manner, e.g., properties, methods, events, attributes (annotations) and other structures. Some programming languages allow access to metadata: type information, type member information and information about applied attributes. But none of the existing mainstream programming languages which support reflection provides fully type safe metadata combining mechanism built in the programming language. Combining of metadata means a class member metadata combining with data, type metadata and constraints. Existing solutions provide no or limited type safe metadata combining mechanism; they are complex and processed at runtime, which by definition is not built-in type-safe metadata combining. Problem can be solved by introducing syntax and methods for type safe metadata combining so that, metadata could be processed at compile time in a fully type safe way. Common metadata combining use cases are data abstraction layer creation and database querying.