ACM SIGAda Ada Letters

Fairleigh Dickinson University, Teaneck, NJ, CORPORATE

doi: 10.1145/181485.181486pmid: N/A

Johns, Janet Faye

doi: 10.1145/181485.181487pmid: N/A

Vladavsky, Luba

doi: 10.1145/181485.181488pmid: N/A

Hirasuna, Michael

doi: 10.1145/181485.181489pmid: N/A

An object oriented reuse strategy based on the Ada 9X inheritance syntax is presented. This paper defines a minimal Ada 9X subset that implements inheritancebased reuse, and outlines its translation to Ada 83. Inheritance allows software modules to be reused without modification to the original source. It is preferred to the "copy and tailor" approach, which has limited software life-cycle benefit since tailored copies need to be tested and maintained.Reuse may be applied at the low level, for components, or at higher levels, for subsystems. Inheritance may be used at any level of reuse, but it is more important for the higher levels. Ada 83 does not support inheritance, but low-level reuse can still be implemented in the form of generic components BOO87. The cost advantage from low-level reuse is already assumed when planning today's software systems. Further cost savings must come from high-level reuse, which needs inheritance to be implemented properly. Inheritance will be fully supported in Ada 9X.The approach presented here may be used in a reuse plan for a system that will start development before Ada 9X becomes viable. The Ada 9X subset allows the system software to be structured for reuse, to be implemented in Ada 83, and to be ready for migration to Ada 9X.This is the second part of a two-part paper. The first part discussed the reuse strategy and defined an Ada 9X subset that will implement it. In this part, a translation from the Ada 9X subset to Ada 83 will be outlined.

Brashear, Phil

doi: 10.1145/181485.181490pmid: N/A

Goldsack, S. J.; Holzbacher-Valero, A. A.; Volz, R.; Waldrop, R.

doi: 10.1145/181485.181491pmid: N/A

Following an initial proposal developed at the 4th Ada Real Time Programming Workshop, Nemacolin Woodlands, 1989, and further meetings to pursue the ideas, a series of papers were published 123 describing and discussing possible Ada language extensions to support the development of distributable programs. The language consisting of Ada with these extensions has been called AdaPT, which may be thought of as Ada with partitions. After introducing AdaPT, this paper describes how the AdaPT constructs can be implemented in Ada 83, and then shows how they can be related to constructs proposed for Ada 9X. In general, the paper endorses the ideas of the 9X team, and suggests an elegant synthesis bringing together two apparently unrealted aspects of the language (type derivation and distribution) that can provide a basis for managing distribution.