This paper describes the syntax and semantics of PSL using a simple text document as a running example and compares PSL to a number of other presentation specification languages. 1 Introduction

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We have implemented a technique for execution of formal, model-based specifications. The specifications we can execute are written at a level of abstraction that has not previously been supported in executable specification languages. The specification abstractions supported by our execution technique include quantified assertions that reference post-state values, and indirect definitions of post-state values (definitions that do not use equality). Our approach is based on translating specifications to the concurrent constraint programming language AKL. While there are, of course, expressible assertions that are not executable, our technique is amenable to any formal specification language based on a finite number of intrinsic types and pre- and postcondition assertions.

. Datalog is the language of deductive databases, a first step towards intelligent relational databases. TwoGroups is a database of p- groups, primarily the groups of order dividing 2 8 , which has seen actually use by research mathematicians. TwoGroups was originally developed on the NU-Prolog platform. We report on our efforts to implement a Datalog interpreter in C++, and to implement TwoGroups in C++ on top of the Datalog platform. Although TwoGroups is very relational in style, its use of range queries means that Datalog is not the perfect platform on which to implement TwoGroups. However, TwoGroups can directly utilise the multi-attribute retrieval algorithms within the Datalog implementation which do support range queries. 1 Introduction TwoGroups is a database of p-groups, primarily the groups of order dividing 2 8 , which has seen actually use by research mathematicians. TwoGroups was originally developed on the NU-Prolog platform. The data is essentially relational so...

In the area of component software, the work so far has concentrated primarily on the key issues of architecture specification and component updating. However, the problems of maintaining application consistency and versioning of components as they evolve have received less attention, and the available solutions are either ad-hoc or not well suited for component applications. In this paper we evaluate these solutions and present a new approach to component versioning developed for the SOFA architecture.

Common LR parser generators lack abstraction facilities for defining recurring patterns of productions. Although there are generators capable of supporting regular expressions on the right hand side of productions, no generator supports user defined patterns in grammars.

Systems become more and more programmable. To design programmable architectures for these systems, we suggested an approach to measure, via simulation, the performance of a set of applications that are mapped on architecture instances. These architecture instances are derived from an architecture template. This requires that we can construct reconfigurable simulators from architecture templates. In this paper, we present our method to efficiently build such reconfigurable simulators. The method consists of 3 steps; the construction of valid architecture instances, the addition of an execution model, and the instrumenting of the executable architecture instance to obtain performance numbers. The method extensively uses Object Oriented principles together with a high-level simulation mechanism to get efficient and reconfigurable simulators. We explain how such reconfigurable simulators can been encapsulated in an environment for automated design space exploration. Keywords--- Performan...

Lacking a global address space, distributed-memory multicomputers present a difficult programming model. High Performance Fortran (HPF) provides a portable, efficient environment for the programmer writing data-parallel applications. Research in the PARADIGM compiler project seeks to alleviate the programmer's burden of writing explicitly parallel applications using non-portable libraries and language extensions by automatically compiling sequential Fortran programs into efficient SPMD messagepassing programs. Because the technology to automatically partition data and detect all parallelism in a sequential program is not mature, HPF provides a standard interface for supplying additional information to the compiler. The information expressed in an HPF program is complementary to the PARADIGM compiler project. HPF allows the programmer to assist the compiler with the process of efficiently compiling code that may eventually be automated, as well as providing information that is impossible to determine at compile time or efficiently at run-time. This thesis presents an overview of HPF, the implementation of HPF in the PARADIGM compiler, and an evaluation of the compiler using several benchmarks. The results demonstrate the effectiveness of the compiler in generating efficient SPMD Fortran code from the HPF code.

The World Wide Web project was started at CERN as a means of improving cooperation between different groups connected via the Internet. The format and location of the information are embedded in the HyperText Transfer Protocol (HTTP), which is used in WWW to move different media from server to client. WWW hypertext documents are marked up in the HyperText Mark-up Language (HTML) making the linking of hypertext documents easier. The present work mainly describes tools which have been developed to provide online support by means of distributed hypermedia for the users of the CERN Program Library. It will be shown that constructing an efficient hypermedia server is more than just writing documentation for on-line purposes. It incorporates the evaluation of different document representations and parsing techniques. Based on our study some general conclusions about the advantages and disadvantages of a hypermedia approach will be drawn.

Generative tools for programming language support have a long history. Tools for interactive language-aware software development are central to the HARMONIA object-oriented framework. However, the generative aspects of HARMONIA are implemented in an ad hoc fashion. This paper explains how systematic generative programming could be used to improve the implementation of HARMONIA and similar systems.