Chapter 13
Classes and Class Hierarchy
Describes the principles, structure, and use of the G2 class hierarchy.
- Introduction
- Overview of the G2 Class Hierarchy
- Items and Classes
- Methods
- Inheritance
- Single Inheritance
- Multiple Inheritance
- Linearization
- Purpose of Inheritance
- System-Defined Classes
- Varieties of System-Defined Classes
- Instantiating System-Defined Classes
- Viewing the Class Hierarchy with the Inspect Facility
- User-Defined Classes
- Extending G2's Machinery with User-Defined Classes
- Representing Knowledge with User-Defined Classes
- Creating User-Defined Classes
- Instantiating User-Defined Classes
- Inheritance in Class Hierarchies
- Direct-superior-classes Attribute
- Class-inheritance-path Attribute
- Using the Class Inheritance Path
- Single Inheritance
- Inheritance of Default Values
- Inheriting Default Values for Stubs
- Inheritance of Methods
- Duplicate Attributes
- Naming Duplicate Attributes
- Referencing Duplicate Attributes
- Duplicate Attributes and Default Values
- Multiple Inheritance
- Multiple Inheritance and Class Inheritance Paths
- Linearizing Multiple Inheritance
- How G2 Linearizes Multiple Inheritance
- The G2 Linearization Algorithm
- Linearizing Two Superior Classes
- Linearizing Several Superior Classes
- Linearizing Networks of Classes
- Why G2 Linearizes As It Does
- Ideal Linearization
- Feasible Linearization
- Compromising Hierarchical Precedence
- Compromising Direct Superior Precedence
- G2 linearization
- Illegal Patterns of Multiple Inheritance
- Disordered Multiple Inheritance
- Meaningless Multiple Inheritance
- Viewing Multiple Inheritance with the Inspect Facility
- Default Values in Multiple Inheritance
- Inheriting a Default Value from a Direct Superior
- Overriding the Default Value of a Direct Superior
- Overriding an Inherited Value with an Explicit Value
- Inheriting Default Values for Stubs
- Duplicate Attributes in Multiple Inheritance
- Defining Classes in Bottom-Up Order
- Deleting a Class Definition
- Planning A Class Hierarchy
Copyright © 1997 Gensym Corporation, Inc.