The object-oriented functional data language

The object-oriented functional data language (O²FDL) is an interactive strongly typed database programming language that integrates the object-oriented and functional programming paradigms. It was designed for advanced applications that require a powerful and uniform database programming language supporting the software engineering principles of these tow paradigms. To this end, the O² FDL supports inheritance and encapsulation of object-oriented languages, and an equational notation and strong typing of functional programming. Strong typing is extended with type restrictions to constrain the instantiations of type variables in function interfaces, while inheritance is augmented with a monotonic subtype rule for function redefinition. The O²FDL also supports novel features. For the core of the O²FDL, a denotational semantics based on an extended λ-calculus is provided. For selected system-defined functions, operational semantics are provided and it is demonstrated that a subset of the O²FDL is at least as expressive as the relational algebra