Heinz Dobler

GPDL: a framework-independent problem definition language for grammar-guided genetic programming

Defining custom problem types in genetic programming (GP) software systems is a tedious task that usually involves the implementation of custom classes and methods including framework-specific code. Users who want to solve a custom problem have to know the details of the targeted framework, for instance cloning semantics, and often have to write a lot of boilerplate code in order to implement the necessary functionality correctly. This can lead to frustration and hinders new developments and the application of GP to solve interesting problems. In this contribution we propose a framework-independent definition language for GP problems that can reduce the required effort and facilitate the integration of new problem types. We draw a parallel between the implementation of compilers for programming languages and the implementation of GP problems and reuse the well-established concept of attributed grammars with semantic actions to define computational symbols, semantics and structural constraints for GP. This goes beyond previous work in the area of context-free-grammar GP and grammatical evolution, because we also interweave the definition of symbol semantics and the target function with the definition of the grammar. This paper describes the proposed GP problem definition language (GPDL) and exemplary definitions of two popular benchmark problems using GPDL. We also describe a reference implementation of a GPDL compiler for HeuristicLab.

Issues in testing collection class libraries

Collections or containers have become a standard facility used by almost any software application. The availability and widespread use of collection class libraries, the large number of systems depending on them, their algorithmic complexity, as well as their object-oriented design demand an elaborated testing approach. Despite the availability of such testing approaches, many industry projects still rely on unstructured unit testing without particular test criteria applied. In this paper we highlight issues involved in testing collection class libraries and report preliminary results from a pilot study on ad-hoc unit testing of collection classes. We show that a reasonable number of defects can be found in a short period of time that higher coverage does not necessarily lead to a larger number of defects found, and report on three distinct strategies used for writing test cases. Still some questions remain and could be discuss in the workshop.

Top-down parsing in Coco-2

Coco-2 [Dobler90] is a new compiler compiler with two interesting features: It allows the specification of the lexical structure, syntax and semantics of a source language within a single document and it implements a new top-down parsing method. This paper focuses on the new parsing method that conveniently incorporates the evaluation of semantic actions in table-driven top-down parsers. The new method is called hybrid because it is a powerful combination of table-driven top-down syntax analysis and the handling of semantic evaluation as implemented in recursive descent parsers. The most notable fact of this method is, that it provides the benefits of table-driven top-down parsing and recursive descent while avoiding their drawbacks.

GenComp --- a generic transformation system

A transformation system can be viewed as a general case of a compiler. This paper introduces a new concept to generate such transformation systems (e.g., compilers), a so called generic compiler. A first version of the generic compiler is described: GenComp, which is the abbreviation for a generic compiler. It first reads a formal description in form of an attributed grammar and then interprets this description in order to transform an input in the source language to an output in the target language.

A model for the migration to object-oriented software development with special emphasis on improvement of acceptance

Object oriented technology has been established as an important new paradigm in software development. Thus, many organizations involved in any kind of software production plan to migrate to object oriented technology or have already started this process. Besides several successful migrations, many failures occur. In order to reduce the risk of failure during the migration process, we developed a migration model based on an empirical study. The application of this model leads to a better understanding of the migration process and supports its planning, designing and implementation, putting special emphasis on improvement of acceptance. The theoretical foundations of our migration model come from technology management, organizational research (i.e. change management, and organizational roles), as well as existing approaches and models for this kind of migration. Our migration model consists of three main parts: the migration process model, the definition of organizational roles, and the use of acceptance strategies such as information and communication, participation, and further education. The main results concerning the rise of acceptance strategies, based on the results of the empirical study, are presented.

Design and Implementation of an Energy Management System for an Integrated Iron and Steel Plant

Energy management is an extremely important task, especially in the context of production processes consuming and/or producing huge amounts of different energy carriers. In this paper we discuss the design and implementation of an energy management system for an integrated iron and steel plant, using object-oriented technology and a relational database.

A hybrid top-down parsing technique

0 Recursive descent parsing allows local semantic objects within each grammar rule. These semantic objects are automatically stacked upon recognition of recursive nonterminals. Parsing speed is maximal, as the recognition of a terminal defaults to a simple comparison instruction. The drawbacks are a grammar-dependent static parser size as well as a lot of code and run-time necessary to implement good error handling and recovery even when analyzing correct source texts.

Observable Runtime Behavior for Defects Indicated by Automated Static Analysis

For the efficient and effective use of automated static analysis of software systems it is crucial to know what kind of errors can be detected and how seriously a reported problem can or should be taken. In the study conducted for this paper we applied a widely used tool (PC-lint) for automated static analysis (ASA) to check C++ code fragments from student exercises. The goal of this research was to discover which types of defects can be identified by automated static analysis. In this paper we present our findings; furthermore the results from classifying the defects are set in relation to detection rules and severity levels provided by ASA, in order to derive insights for calibrating ASA tools in a specific application context.

An object-oriented and generic compiler generator

Object-oriented software development has become the de-facto standard programming paradigm used in modern software systems. Additionally genericity has grown more popular since the enhancement of Java and C#. This paper attempts to reconsider the principles of compiler construction from this modern, object-oriented point of view. We present a multi-paradigm, mainly object-oriented and generic approach for creating a compiler generator using a combination of the Interpreter pattern and the Visitor pattern. A prototype of such an object-oriented and generic compiler generator has also been developed using C# 2.0 and will serve as a reference to explain the design throughout this paper.