GNU Smalltalk User's Guide
4.9 Coexisting in the Class Hierarchy
The early chapters of this tutorial discussed classes in
one of two ways. The "toy" classes we developed were rooted
at Object; the system-provided classes were treated as
immutable entities. While one shouldn't modify the behavior
of the standard classes lightly, "plugging in" your own
classes in the right place among their system-provided
brethren can provide you powerful new classes with very little
effort.
This chapter will create two complete classes which
enhance the existing Smalltalk hierarchy. The discussion
will start with the issue of where to connect our new
classes, and then continue onto implementation. Like most
programming efforts, the result will leave many possibilities
for improvements. The framework, however, should begin
to give you an intuition of how to develop your own
Smalltalk classes.
