In an orthogonally persistent programming system the longevity of data is independent of its other attributes. The advantages of persistence may be seen primarily in the areas of data modelling and protection resulting from simpler semantics and reduced complexity. These have been verified by the first implementations of persistent languages, typically consisting of a persistent store, a run-time system and a compiler that produces programs that may access and manipulate the persistent environment. This thesis demonstrates that persistence can deliver many further benefits to the programming process when applied to software construction and execution. To support the thesis, a persistent environment has been extended with all the components necessary to support program construction and execution entirely within the persistent environment. This is the first known example of a strongly-typed integrated persistent programming environment. The keystone of this work is the construction of ...

Research into persistent programming languages and systems in recent years has shown that the technology is useful for developing complex software in many problem domains. This paper explores the issues of adding persistence support to Ada, either as extensions to Ada 9X, or as an integral part of the next version of the language. 1. Introduction This paper explores the options for supporting persistence in Ada. In the introduction, we establish the setting for the paper by explaining why this is an issue worth considering. 1.1. The Ada programming language TheAda programming language arose from a US Department of Defence (DoD) initiative started in the mid 1970's to develop a High Order Language (HOL) suitable for embedded systems software. The original Ada language proposal, which was one of the four responses to the Ironman/Steelman requirements documents [47], was refined to a proposed standard [28,48] by 1980 and standardised in 1983 [49]. Our analysis of the requirements and s...

Program visualization focuses on the graphical representation of an executing program and its data. The information is presented in a form designed to enhance both the understanding and productivity of the programmer through the efficient use of the human visual system. The programmer is able to observe patterns of behaviour within the executing code and rapidly detect a departure from the expected behaviour patterns in an accurate way. However, depending on the programming paradigm and architectural platform that is utilized, the variety and manner in which information is best presented varies somewhat. This paper attempts to analyse the visualization requirements for a variety of programming paradigms and architectural platforms, detailing the paradigm and platform specific needs, in addition to general visualization requirements that extend across paradigms and platforms. A survey of current visualization systems is presented which examines each system in detail and categorizes it by the programming paradigms/platform that it is designed to visualize. A comparison of the various visualization systems is also presented and the achievements and failures of current visualization technology are highlighted and commented upon. 1.

this paper, we will present our initial ideas on the creation of an integrated environment for the development of persistent systems. Naturally, this development system will, by necessity, be resident within the total persistent environment. As such, a persistent object store provides the basis for the integrated programming environment. The result is an environment which differs significantly from those which have been developed as an adjunct to traditional programming practices in a file-based operating system. In this paper, we present our initial ideas on such an environment. In particular, we focus on potential uses for hyperlinking in the environment. 2

This paper illustrates the variety of visualization techniques that are employed for various programming paradigms, examining the type of information required and the advantages that the information provides the programmer. We examine the specific visualization requirements for each paradigm and the general requirements of visualization systems which depict the flow of control for both sequential and parallel program execution. We find that many of the visualization systems currently available tend to focus on only one aspect of the visualization requirements rather than the broad base of needs of the programmer. The need to integrate these visualization systems in the future is highlighted. 1. INTRODUCTION Program visualization focuses on the graphical representation of an executing program and its data. This information is presented in a form designed to enhance both the understanding and productivity of the programmer through the efficient use of the human visual system. The progra...

. Research into persistent programming languages and systems in recent years has shown that the technology is useful for developing complex software in many problem domains. This paper explores the issues and consequences of adding persistence to Ada95. The persistence extensions support transparent migration of objects between a program's address space and a persistent store in a way that preserves both type safety and encapsulation of abstract data types. Keywords and Phrases: Kinds of systems: persistent systems; Ada95; object-oriented technology. 1 Introduction Ada has recently undergone an intensive and major review and update. The result of this is the new programming language Ada95[23] which is, in the main, backward compatible with Ada83[36]. Two of the principle changes to Ada were the addition of new constructs to change it from an object-based language to a fully fledged object-oriented language and the provision of annexes defining additional language capabilities for spec...

Datatypes..............................................................15 2.3.10 Files.....................................................................................15 2.3.11 Universes ............................................................................15 2.3.12 Types...................................................................................16 2.3.13 Browser Background Menu................................................17 2.3.14 Panning Tool.......................................................................17 2.4 Declaration Sets .....................................................................................18 2.4.1 Creating and Deleting Declaration Sets..............................18 2.4.2 Adding To a Declaration Set ..............................................19 2.4.3 Displaying a Declaration Set ..............................................19 2.4.4 Choosing Declaration Sets..................................................20 2.5 The Output Window...

Most existing file based operating systems tend to provide very little in the way of type related information about applications to the user. Instead, the user is required to construct applications that perform their own type checking, relying on information about existing programs and data to be obtained via other means, such as manual pages, or by visual inspection of source code. This lack of public type related information has, by and large, prevented the benefits of browsing technology as found in some persistent language systems to be delivered to the operating system level. A technique is examined in which detailed type information about operating system entities may be recorded, thus enabling more informative user interfaces, tools and applications to be constructed. 1 . Introduction The development of persistent systems has sparked the emergence of a variety of new programming techniques and tools. In particular, persistent store browsers [4,7,8,14] have been developed which...