Ada in Practice started lifeas a case studies report, the result of work per formed under government contract at SofTech, Inc. as part of an effort to identify and resolve issues related to Ada usage. Although that report has now evolved into a book intended for a more general audience, its objectives are largely unchanged. Asbefore,the primary goal is to promote effective use of Ada, both in general programming and design practice and in embedded computer systems specifically. Many features of Ada will be new to pro grammers and designers familiar with other languages; the program examples presented in the case studies are intended to serve as guidelines for proper usage of such features while pointing out common misconceptions and programming errors. In addition, we hope that this book as a whole will highlight the advan tages of using Ada at all stages of a program's life cycle, from problem analysis through testing and maintenance. However, it does not purport to hold all the answers to questions ofAda application;areas that would benefit from further investigation or more definitive guidelines are also suggested.

Inhaltsangabe1. Naming Conventions.- 1.1 Guidelines for the Selection of Identifiers.- Problem: Naming Entities in a Message-Switch Program.- 2. Types.- 2.1 Discrete Types.- Problem: Message Classification Types.- 2.2 Implementation of Set Types.- Problem: Sets of Communities in a Message-Switch Program.- 2.3 Constant Array Declarations.- Problem A: Message Transmission Identifier Strings.- Problem B: A Baud Rate Table for a Message-Switch Program.- 2.4 Record Types.- Problem: Storing Message History Information.- 2.5 Recursive Type Definitions.- Problem A: Linked Lists of Physical Transmission Lines.- Problem B: Defining Data File Elements as Access Types.- 3. Coding Paradigms.- 3.1 Use of Slices.- Problem A: Operations on Message Strings.- Problem B: Constituent Fields of Text Lines.- 3.2 Short Circuit Control Forms.- Problem A: Inappropriate Optimization in a Date Package.- Problem B: Inappropriate Optimization in Message Comparison.- Problem C: Avoiding Constraint-Error in Loops.- 3.3 Loop Statements.- Problem: Three Approaches to Searching an Array.- 3.4 Use of Block Statements for Local Renaming.- Problem: Determining Transmission Line Precedence.- 4. Exceptions.- 4.1 The Use of Exceptions.- Problem A: Implementing a Control Structure (Zahn's Construct).- Problem B: Handling Expected Counter Wrap Around.- Problem C: Error Conditions in a Stack Package.- Problem D: Responding to Invalid Time Input.- Problem E: Handling Interface Malfunctions in a Message Switch.- Problem F: Unanticipated Message Validation Errors.- 5. Program Structure.- 5.1 Specifying Interfaces for General Purpose, Portable Software: A Study of Ada Input/Output.- Problem A: Preserving Implementation Freedom.- Problem B: Providing Parameters with Default Values.- Problem C: Assumptions about Underlying Hardware/Software Support.- Problem D: Error Recovery and Exceptions.- Problem E: Compiler-Dependent Specifications.- 5.2 Information Hiding.- Problem: A Clock Simulation for Message Interrupts.- 5.3 Reducing Depth of Nesting.- Problem A: Entries in a Message-Switch Log.- Problem B: Conditional Execution of Task Calls.- Problem C: Using Subunits to Condense a Complex Package Body.- 5.4 Library Units Versus Subunits.- Problem: The Modular Structure of a Message-Switch Program.- 6. Ada Life Cycle Design Methodology.- 6.1 Problem Analysis.- 6.2 Requirements Definition.- 6.3 High-Level Design.- 6.4 Low-Level Design.- 6.5 Coding.- 6.6 Unit Testing.- 6.7 Integration Testing.- 6.8 Acceptance Testing.- 6.9 Maintenance.- Appendix A. Areos for Future Study.- A.1 Design Issues.- A.2 Data Abstraction Issues.- A.3 Additional Naming Conventions.- A.4 Additional Coding Paradigms.- A.5 Operational Issues.- Appendix B. Bibliography.