Object Oriented extensions

The latest drop of ForthOS has facilities available for OO programming.
These are all located in the "extensions" vocabulary.

Object subclass: MyClass
    Creates a new class, inheriting from Object (the base class)

ivars: int8 field1 int16 field2 int8 dummy endivars
    Adds fields to the most recently defined class (using "struct" syntax)

MyClass :method field2! { val self -- }
        val self MyClass>field2 w! method;
    Defines a method for MyClass... uses the named arguments support (not
    really a part of the OO package, but fits nicely) to store the
    passed value into a field of an instance

MyClass new constant var1
123 var1 -> field2!
    "-> <selector>" invokes a method of the passed object.

Inheritance works, so if you did:

Object :method sayHi { self -- } ." Hello, world." cr method;
var1 -> sayHi

you would indeed see the printed message, inherited by the MyClass object
out of Object's method table.

Andy
Received on 26 Jul 2004 19:17:38 GMT