On the basis for ELF - An Extensible Language Facility

Computer language for data processing and information retrieva

1957-2007: 50 Years of Higher Order Programming Languages

Fifty years ago one of the greatest breakthroughs in computer programming and in the history of computers happened – the appearance of FORTRAN, the first higher-order programming language. From that time until now hundreds of programming languages were invented, different programming paradigms were defined, all with the main goal to make computer programming easier and closer to as many people as possible. Many battles were fought among scientists as well as among developers around concepts of programming, programming languages and paradigms. It can be said that programming paradigms and programming languages were very often a trigger for many changes and improvements in computer science as well as in computer industry. Definitely, computer programming is one of the cornerstones of computer science. Today there are many tools that give a help in the process of programming, but there is still a programming tasks that can be solved only manually. Therefore, programming is still one of the most creative parts of interaction with computers. Programmers should chose programming language in accordance to task they have to solve, but very often, they chose it in accordance to their personal preferences, their beliefs and many other subjective reasons. Nevertheless, the market of programming languages can be merciless to languages as history was merciless to some people, even whole nations. Programming languages and developers get born, live and die leaving more or less tracks and successors, and not always the best survives. The history of programming languages is closely connected to the history of computers and computer science itself. Every single thing from one of them has its reflexions onto the other. This paper gives a short overview of last fifty years of computer programming and computer programming languages, but also gives many ideas that influenced other aspects of computer science. Particularly, programming paradigms are described, their intentions and goals, as well as the most of the significant languages of all paradigms

AN ENVIRONMENT FOR ENGINEERING EXTENDED AFFIX GRAMMAR ENVIRONMENTS

Existing formalisms for the specification of programming environments are complex and strongly biased by the problems of environment generation. It has been investigated whether a simple two-level grammar, describing a programming language, can be used without further modification for the generation of an environment for that language. We believe that there is enough information in most language definitions - albeit implicitly - to generate most of the tools used in syntax-directed editors. This paper proposes some simple and elegant improvements in the use of place- holders and templates, and in the unparsing mechanism. Although the improvements are implemented in a completely newly designed prototype they can also be applied to existing syntax-directed editors to improve their workability

Implementation of a Scientific Subset of Algol 68

Computing and Information Science

Interactive use of a computer in the preparation of structured progams

PhD ThesisAn experimental system providing assistance in the task of program construction, validation and description is presented. This system (Pearl) encourages a particular top-down approach to programming such that programs so developed exhibit a multi-level, hierarchical structure. Amongst several tools provided by the system is one ·"hich enables programs to be exercised even though they may be eXercised in terms of abstract operations and data types. The whole system is designed to be used in an interactive environment. Programs are developed by the programmer with appropriate assistance and guidance from the computer. Contemporary programming tools and methods are surveyed and their relevance to the development of high quality software is discussed. In particular attention is given to programming methodologies,design representations and issues of program correctness. The practicality of the system is demonstrated i!l a mmber of examples.Science Research Council

Automating the teaching of artificial language using production systems

The work to be described here is an investigation into the means whereby the learning of programming languages may be made easier. The role of formal definitions of programming languages is studied and a system is described which utilises production systems as the basis for generating an environment in which students may test their understanding of programming languages. This system for automating the teaching of programming languages provides an experimental testbed for carrying out further investigations into programming behaviour

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

Software maintenance: generating front ends for cross referencer tools

This thesis surveys the activities performed in software maintenance and identifies some of the software tools which can be utilised by the maintenance programmer. The most expensive phase of software maintenance is surveyed in more detail and tools to support this activity are identified. A new class of cross referencer tool was designed and investigated. The novel aspect of the cross referencer is that it can be used on more than one language, by utihzing grammar driven generators to customize and make maximum re-use of the language independent components, allowing language specific implementations to be generated with minimal effort. The cross referencer also extends an idea of having different levels of detail in cross reference listings by allowing the tool implementor to specify the contents of each level of detail. A proposed experimental toolkit for the automatic construction of these cross referencer front end tools, from non procedural specifications, is designed and investigated