PROLOG++

PROLOG++ is an extension of LPA-PROLOG by the company Apple Comp. The language combines the non- procedural programming in PROLOG with the powerful object-oriented modeling mechanism. PROLOG++ is an extension which is first translated to PROLOG and works inefficiently accordingly. But like LISP, data (including objects, class descriptions) are treated like code (predicates) - classes can be introduced or modified at runtime.

The programming language PROLOG++ is not statically typed. There is the possibility of inheritance and overwriting like overloading of methods is possible. Since PROLOG++ is untyped, polymorphism is automatically given. On the other hand abstract classes and metaclasses are not supported.

There are public, private and local methods. Generic (parameterizable) classes cannot be defined. The runtime system offers an automatic memory management for the release of not referenced objects. Thus in PROLOG++ all variables are managed by the system.

PROLOG++ is a descriptive language, in which a problem domain is described by predicates and not by solution algorithms (specification). In addition to "passive" objects, "Deamon" objects can also be defined, which react independently depending on certain object states. There are graphical development environments like MacObject.