Type Inheritance and Relational Theory

Contents

Preface

Foreword

PART I           PRELIMINARIES

Chapter 1       Background

Inheritance arises naturally

A fundamental concept

The suppliers-and-parts database

A little history

Exercises

Answers

Chapter 2       Types without Inheritance

Values vs. variables

What’s a type?

Scalar vs. nonscalar types

Types vs. representations

The TYPE statement

Operators

Type generators

Miscellaneous issues

Concluding remarks

Exercises

Answers

Chapter 3       Types with Inheritance

Why inheritance?

Toward a model of inheritance

Single vs. multiple inheritance

Scalars, tuples, and relations

The running example

More terminology

Substitutability

A BNF grammar

More terminology bis

Concluding remarks

Exercises

Answers

Chapter 4       The Inheritance Model

The IM prescriptions

PART II          SCALAR TYPES, SINGLE INHERITANCE

Chapter 5       Basic Definitions

IM Prescription 1: Types are sets

IM Prescription 2: Subtypes are subsets

IM Prescription 3: “Subtype of” is reflexive

IM Prescription 4: “Subtype of” is transitive

IM Prescription 5: Proper and immediate subtypes and supertypes

IM Prescription 6: Scalar root and leaf types

IM Prescription 7: Disjoint and overlapping types

Exercises

Answers

Chapter 6       Scalar Values with Inheritance

IM Prescription 8: Common subtypes and supertypes

Common subtypes

Common supertypes

Intersection types vs. union types

Concluding remarks

Exercises

Answers

Chapter 7       Scalar Variables with Inheritance

IM Prescription 9: Model of a scalar variable

Inclusion ...