C. Verhoef
VU University Amsterdam
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Publication
Featured researches published by C. Verhoef.
ACM Transactions on Software Engineering and Methodology | 2005
Paul Klint; Ralf Lämmel; C. Verhoef
Grammarware comprises grammars and all grammar-dependent software. The term grammar is meant here in the sense of all established grammar formalisms and grammar notations including context-free grammars, class dictionaries, and XML schemas as well as some forms of tree and graph grammars. The term grammar-dependent software refers to all software that involves grammar knowledge in an essential manner. Archetypal examples of grammar-dependent software are parsers, program converters, and XML document processors. Despite the pervasive role of grammars in software systems, the engineering aspects of grammarware are insufficiently understood. We lay out an agenda that is meant to promote research on increasing the productivity of grammarware development and on improving the quality of grammarware. To this end, we identify the problems with the current grammarware practices, the barriers that currently hamper research, and the promises of an engineering discipline for grammarware, its principles, and the research challenges that have to be addressed.
IEEE Software | 2010
Johan Laurenz Eveleens; C. Verhoef
This paper presents the chaos report figures that are often used to indicate problems in application software development project management, the reports contain major flaws.
Software - Practice and Experience | 2001
Ralf Lämmel; C. Verhoef
We propose an approach to the construction of grammars for existing languages. The main characteristic of the approach is that the grammars are not constructed from scratch but they are rather recovered by extracting them from language references, compilers and other artifacts. We provide a structured process to recover grammars including the adaptation of raw extracted grammars and the derivation of parsers. The process is applicable to possibly all existing languages for which business critical applications exist. We illustrate the approach with a non‐trivial case study. Using our process and some basic tools, we constructed in a few weeks a complete and correct VS COBOL II grammar specification for IBM mainframes. In addition, we constructed a parser for VS COBOL II, and were the first to publish a (Web‐enabled) grammar specification so that others can use this result to construct their own grammar‐based tools for VS COBOL II or derivatives. Copyright
Science of Computer Programming | 2002
C. Verhoef
We present a quantitative approach for IT portfolio management. This is an approach that CMM level 1 organizations can use to obtain a corporate wide impression of the state of their total IT portfolio, how IT costs spent today project into the budgets of tomorrow, how to assess important risks residing in an IT portfolio, and to explore what-if scenarios for future IT investments. Our quantitative approach enables assessments of proposals from business units, risk calculations, cost comparisons, estimations of TCO of entire IT portfolios, and more. Our approach has been applied to several organizations with annual multibillion dollar IT budgets each, and has been instrumental for executives in coming to grips with the largest production factor in their organizations: information technology.
workshop on program comprehension | 1998
M.G.J. van den Brand; Alex Sellink; C. Verhoef
We evaluate the parsing technology used by people working in the reengineering industry. We discuss parser generators and complete systems like Yacc, TXL, TAMPR, REFINE, CobolTransformer, COSMOS, and ASF+SDF. We explain the merits and drawbacks of the various techniques. We conclude that current technology may cause problems for the reengineering industry and that modular and/or compositional parsing techniques are a possible solution.
Science of Computer Programming | 2000
Mark G. J. van den Brand; Alex Sellink; C. Verhoef
We present an approach for the generation of components for a software renovation factory. These components are generated from a contex-free grammar definition that recognizes the code that has to be renovated. We generate analysis and transformation components that can be instantiated with a specific transformation or analysis task. We apply our approach to COBOL and we discuss the construction of realistic software renovation components using our approach.
IEEE Software | 2001
Ralf Lämmel; C. Verhoef
Constructing analysis and modification tools for software assets is laborious because you first need to implement the underlying parser for the softwares specific programming language. These implementations are generally not in the public domain. So, parser development for any of the 500+ languages in use today implies a major up-front investment. The authors propose a solution that will work for virtually all languages: the rapid development of renovation parsers by stealing the grammars. They also share lessons learned.
Software - Practice and Experience | 2003
D. Faust; C. Verhoef
We describe a method to migrate multiple instances of a successful single information system to a product line. The deployed product line is able to deal with the variants evolved over time in a cost‐effective manner. We proposed and used federated architectures that partition the software into so‐called genericity layers. We argue that federated architectures are at the heart of product lines, and we provide compelling arguments as to why federated architectures are a sound weapon in todays corporate strategy: they enable smooth enterprise integration and rapid change. We support our arguments with a real‐world case: we successfully migrated a large global transaction and settlement system with many site‐specific variations to a product line with a federated architecture. Moreover, we measured the success rate of this architectural modification effort by showing that the annual direct cost savings are of the order of millions of dollars during the deployment of the product line. Copyright
IEEE Software | 2000
Andrey Terekhov; C. Verhoef
Billions of lines written in Cobol, PL/I, and other mature high level languages are still in active use. Many developers have tried to convert these languages to more modern ones, but few have succeeded. The article sheds light on the realities of language conversions and discusses the possibilities and limitations of automated language converters.
Information & Computation | 1998
Wan Fokkink; C. Verhoef
We set up a formal framework to describe transition system specifications in the style of Plotkin. This framework has the power to express many-sortedness, general binding mechanisms, and substitutions, among other notions such as negative hypotheses and unary predicates on terms. The framework is used to present a conservativity format in operational semantics, which states sufficient criteria to ensure that the extension of a transition system specification with new transition rules does not affect the semantics of the original terms.