CONTENTS xxiii 20.3 A FUNCTIONAL,TOP-DOWN SOLUTION 678 20.4 A CRITIQUE OF THE SOLUTION 682 20.5 AN OBJECT-ORIENTED ARCHITECTURE 684 20.6 DISCUSSION 693 20.7 BIBLIOGRAPHICAL NOTE 694 Chapter 21:Inheritance case study:"undo"in an interactive system 695 21.1 PERSEVERARE DIABOLICUM 695 21.2 FINDING THE ABSTRACTIONS 699 21.3 MULTI-LEVEL UNDO-REDO 704 21.4 IMPLEMENTATION ASPECTS 707 21.5 A USER INTERFACE FOR UNDOING AND REDOING 711 21.6 DISCUSSION 712 21.7 BIBLIOGRAPHICAL NOTES 715 EXERCISES 715 Chapter 22:How to find the classes 719 22.1 STUDYING A REQUIREMENTS DOCUMENT 720 22.2 DANGER SIGNALS 726 22.3 GENERAL HEURISTICS FOR FINDING CLASSES 731 22.4 OTHER SOURCES OF CLASSES 735 22.5 REUSE 740 22.6 THE METHOD FOR OBTAINING CLASSES 741 22.7 KEY CONCEPTS INTRODUCED IN THIS CHAPTER 743 22.8 BIBLIOGRAPHICAL NOTES 744 Chapter 23:Principles of class design 747 23.1 SIDE EFFECTS IN FUNCTIONS 748 23.2 HOW MANY ARGUMENTS FOR A FEATURE? 764 23.3 CLASS SIZE:THE SHOPPING LIST APPROACH 770 23.4 ACTIVE DATA STRUCTURES 774 23.5 SELECTIVE EXPORTS 796 23.6 DEALING WITH ABNORMAL CASES 797 23.7 CLASS EVOLUTION:THE OBSOLETE CLAUSE 802 23.8 DOCUMENTING A CLASS AND A SYSTEM 803 23.9 KEY CONCEPTS INTRODUCED IN THIS CHAPTER 806 23.10 BIBLIOGRAPHICAL NOTES 806 EXERCISES 807CONTENTS xxiii 20.3 A FUNCTIONAL, TOP-DOWN SOLUTION 678 20.4 A CRITIQUE OF THE SOLUTION 682 20.5 AN OBJECT-ORIENTED ARCHITECTURE 684 20.6 DISCUSSION 693 20.7 BIBLIOGRAPHICAL NOTE 694 Chapter 21: Inheritance case study: “undo” in an interactive system 695 21.1 PERSEVERARE DIABOLICUM 695 21.2 FINDING THE ABSTRACTIONS 699 21.3 MULTI-LEVEL UNDO-REDO 704 21.4 IMPLEMENTATION ASPECTS 707 21.5 A USER INTERFACE FOR UNDOING AND REDOING 711 21.6 DISCUSSION 712 21.7 BIBLIOGRAPHICAL NOTES 715 EXERCISES 715 Chapter 22: How to find the classes 719 22.1 STUDYING A REQUIREMENTS DOCUMENT 720 22.2 DANGER SIGNALS 726 22.3 GENERAL HEURISTICS FOR FINDING CLASSES 731 22.4 OTHER SOURCES OF CLASSES 735 22.5 REUSE 740 22.6 THE METHOD FOR OBTAINING CLASSES 741 22.7 KEY CONCEPTS INTRODUCED IN THIS CHAPTER 743 22.8 BIBLIOGRAPHICAL NOTES 744 Chapter 23: Principles of class design 747 23.1 SIDE EFFECTS IN FUNCTIONS 748 23.2 HOW MANY ARGUMENTS FOR A FEATURE? 764 23.3 CLASS SIZE: THE SHOPPING LIST APPROACH 770 23.4 ACTIVE DATA STRUCTURES 774 23.5 SELECTIVE EXPORTS 796 23.6 DEALING WITH ABNORMAL CASES 797 23.7 CLASS EVOLUTION: THE OBSOLETE CLAUSE 802 23.8 DOCUMENTING A CLASS AND A SYSTEM 803 23.9 KEY CONCEPTS INTRODUCED IN THIS CHAPTER 806 23.10 BIBLIOGRAPHICAL NOTES 806 EXERCISES 807