The Green language
Green is a statically typed object-oriented language which supports parameterized classes, metaobjects, introspective reflection, and classes as first-class objects. Its exception system is completely object-oriented for it encapsulates in classes not only exceptions but also exception handling. The language definition of subtyping is more encompassing than subclassing, thus improving polymorphism. Classes are classless objects which have themselves types. This makes classes first-class objects without the problems associated with languages in which every class is an object of another class, its metaclass. Every basic value such as 7 or A is considered as an object whenever necessary which makes programming easy and increases polymorphism.
object-oriented languages polymorphism type systems exception handling system