Object-oriented programming language

Formal semantics

Researchers have tried to formally define the semantics of OOP. Inheritance presents difficulties, particularly with the interactions between open recursion and encapsulated state. Researchers have used recursive types and co-algebraic data types to incorporate essential features of OOP. Abadi and Cardelli defined several extensions of System F_<: that deal with mutable objects, allowing both subtype polymorphism and parametric polymorphism (generics), and were able to formally model many OOP concepts and constructs. Although far from trivial, static analysis of object-oriented programming languages such as Java is a mature field, with several commercial tools.