On the engineering of crucial software

The various aspects of the conventional software development cycle are examined. This cycle was the basis of the augmented approach contained in the original grant proposal. This cycle was found inadequate for crucial software development, and the justification for this opinion is presented. Several possible enhancements to the conventional software cycle are discussed. Software fault tolerance, a possible enhancement of major importance, is discussed separately. Formal verification using mathematical proof is considered. Automatic programming is a radical alternative to the conventional cycle and is discussed. Recommendations for a comprehensive approach are presented, and various experiments which could be conducted in AIRLAB are described

Implementation of a Modula 2 subset compiler supporting a \u27C\u27 language interface using commonly available UNIX tools

Modula 2 has been proposed as an appropriate language for systems programming. Smaller than PASCAL but more structured than \u27C\ Modula 2 is intended to be relatively easy to implement. A realization of a subset of Modula 2 for the MC68010 microprocessor is presented. Widely available UNIX tools and the \u27C language are used for the implementation. A mechanism for calling \u27C language functions from Modula 2 (and vice versa) is suggested. Critical source code, grammar, and an extensive bibliography pertinent to the implementation are included as appendices

Programming language trends : an empirical study

Predicting the evolution of software engineering technology trends is a dubious proposition. The recent evolution of software technology is a prime example; it is fast paced and affected by many factors, which are themselves driven by a wide range of sources. This dissertation is part of a long term project intended to analyze software engineering technology trends and how they evolve. Basically, the following questions will be answered: How to watch, predict, adapt to, and affect software engineering trends? In this dissertation, one field of software engineering, programming languages, will be discussed. After reviewing the history of a group of programming languages, it shows that two kinds of factors, intrinsic factors and extrinsic factors, could affect the evolution of a programming language. Intrinsic factors are the factors that can be used to describe the general desigu criteria of programming languages. Extrinsic factors are the factors that are not directly related to the general attributes of programming languages, but still can affect their evolution. In order to describe the relationship of these factors and how they affect programming language trends, these factors need to be quantified. A score has been assigued to each factor for every programming language. By collecting historical data, a data warehouse has been established, which stores the value of each factor for every programming language. The programming language trends are described and evaluated by using these data. Empirical research attempts to capture observed behaviors by empirical laws. In this dissertation, statistical methods are used to describe historical programming language trends and predict the evolution of the future trends. Several statistics models are constructed to describe the relationships among these factors. Canonical correlation is used to do the factor analysis. Multivariate multiple regression method has been used to construct the statistics models for programming language trends. After statistics models are constructed to describe the historical programming language trends, they are extended to do tentative prediction for future trends. The models are validated by comparing the predictive data and the actual data

Design and implementation of a programmable middleware

This thesis presents a languagebased, safely programmable middleware for the simple, highlevel, and expressive construction of composable open systems. The middleware provides services for pickling, components, and distribution. All are based on a minimal set of primitives and syntax extensions, such that they otherwise can be completely implemented and customized in a highlevel language with automatic memory management, exception handling, higherorder functions, futures, and dynamic types. Using this approach, it becomes possible to describe the complete architecture of the middleware system, and to leverage the language\u27;s safety features in the middleware itself.Die vorliegende Arbeit beschreibt eine Programmiersprachenbasierte programmierbare Middleware, die eine einfache Konstruktion offener Systeme auf hoher Ebene ermöglicht. Die Middleware bietet Dienste für Pickling, Komponenten und Verteilung an, die allesamt auf einem minimalen Satz an Primitiven und Syntaxerweiterungen beruhen. Der Hauptteil der Dienste kann so in einer höheren Programmiersprache mit automatischer Speicherverwaltung, Ausnahmebehandlung, Prozeduren höherer Ordnung, Futures und dynamischen Typen realisiert werden. Dies ermöglicht es, die Architektur der Middleware vollständig zu beschreiben, sowie die Sicherheitsgarantien der höheren Programmiersprache in der Implementierung der Middleware selbst zu nutzen

On the Utilisation of Persistent Programming Environments

There is a growing gap between the supply and demand of good quality software, which is primarily due to the difficulty of the programming task and the poor level of support for programmers. Programming is carried out using software tools which do not match very well either real world understanding of a problem or even the other tools which need to be used. In every phase of software production, the programmer must master new tools which function in a different way from each other. The Persistent Programming Paradigm attempts to reduce these problems by providing a programming environment which gives consistent methods of accessing program values of various kinds. Long-term and short-term data are treated in the same way. Numbers, text, graphical values and even program objects are all referred to in the same consistent way. Languages which support persistence provide considerable power within a simple environment, so that programmers can perform most if not all parts of the programming task in a coherent and uniform manner. This thesis tests the hypothesis that programmers do in fact derive some benefit from this - the simplification of the program and faster implementation of complex programs. The persistent language PS-algol is introduced and used to build: user-interface and compiler tools; a database application; some data modelling tools, both relational and semantic; a rapid prototyping system; an object-oriented language; and software support systems. In doing so, the thesis demonstrates the breadth of work which can be achieved using a Persistent Programming Language, and the ease with which these various projects can be implemented. Further, the thesis derives the beginnings of a methodology for using such a language and analyses how PS-algol could be improved. In doing so, the work aims to put the Persistent Programming Paradigm on a firm basis following significant use and experimentation