@article{HirschfeldKawarnura2006, author = {Hirschfeld, Robert and Kawarnura, Katsuya}, title = {Dynamic service adaptation}, series = {Software : practice \& experience}, volume = {36}, journal = {Software : practice \& experience}, number = {11-12}, publisher = {Wiley}, address = {Chichester}, issn = {0038-0644}, doi = {10.1002/spe.766}, pages = {1115 -- 1131}, year = {2006}, abstract = {Change can be observed in our environment and in the technology we build. While changes in the environment happen continuously and implicitly, our technology has to be kept in sync with the changing world around it. Although we can prepare for some of the changes for most of them we cannot. This is especially true for next-generation mobile communication systems that are expected to support the creation of a ubiquitous society where virtually everything is connected and made available within an organic information network. Resources will frequently join or leave the network, new types of media or new combinations of existing types will be used to interact and cooperate, and services will be tailored to preferences and needs of individual customers to better meet their needs. This paper outlines our research in the area of dynamic service adaptation to provide concepts and technologies allowing for such environments. Copyright (C) 2006 John Wiley \& Sons, Ltd.}, language = {en} } @article{HauptAdamsTimbermontetal.2009, author = {Haupt, Michael and Adams, Bram and Timbermont, Stijn and Gibbs, Celina and Coady, Yvonne and Hirschfeld, Robert}, title = {Disentangling virtual machine architecture}, issn = {1751-8806}, doi = {10.1049/iet-sen.2007.0121}, year = {2009}, abstract = {Virtual machine (VM) implementations are made of intricately intertwined subsystems, interacting largely through implicit dependencies. As the degree of crosscutting present in VMs is very high, VM implementations exhibit significant internal complexity. This study proposes an architecture approach for VMs that regards a VM as a composite of service modules coordinated through explicit bidirectional interfaces. Aspect-oriented programming techniques are used to establish these interfaces, to coordinate module interaction, and to declaratively express concrete VM architectures. A VM architecture description language is presented in a case study, illustrating the application of the proposed architectural principles.}, language = {en} } @book{GellerHirschfeldBracha2010, author = {Geller, Felix and Hirschfeld, Robert and Bracha, Gilad}, title = {Pattern Matching for an object-oriented and dynamically typed programming language}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-065-6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-43035}, publisher = {Universit{\"a}t Potsdam}, pages = {81}, year = {2010}, abstract = {Pattern matching is a well-established concept in the functional programming community. It provides the means for concisely identifying and destructuring values of interest. This enables a clean separation of data structures and respective functionality, as well as dispatching functionality based on more than a single value. Unfortunately, expressive pattern matching facilities are seldomly incorporated in present object-oriented programming languages. We present a seamless integration of pattern matching facilities in an object-oriented and dynamically typed programming language: Newspeak. We describe language extensions to improve the practicability and integrate our additions with the existing programming environment for Newspeak. This report is based on the first author's master's thesis.}, language = {en} } @book{HauptMarrHirschfeld2011, author = {Haupt, Michael and Marr, Stefan and Hirschfeld, Robert}, title = {CSOM/PL : a virtual machine product line}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-134-9}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-52332}, publisher = {Universit{\"a}t Potsdam}, pages = {26}, year = {2011}, abstract = {CSOM/PL is a software product line (SPL) derived from applying multi-dimensional separation of concerns (MDSOC) techniques to the domain of high-level language virtual machine (VM) implementations. For CSOM/PL, we modularised CSOM, a Smalltalk VM implemented in C, using VMADL (virtual machine architecture description language). Several features of the original CSOM were encapsulated in VMADL modules and composed in various combinations. In an evaluation of our approach, we show that applying MDSOC and SPL principles to a domain as complex as that of VMs is not only feasible but beneficial, as it improves understandability, maintainability, and configurability of VM implementations without harming performance.}, language = {en} } @article{HirschfeldSteinertLincke2011, author = {Hirschfeld, Robert and Steinert, Bastian and Lincke, Jens}, title = {Agile software development in virtual collaboration environments}, isbn = {978-3-642-13756-3}, year = {2011}, language = {en} } @article{LinckeAppeltauerSteinertetal.2011, author = {Lincke, Jens and Appeltauer, Malte and Steinert, Bastian and Hirschfeld, Robert}, title = {An open implementation for context-oriented layer composition in ContextJS}, series = {Science of computer programming}, volume = {76}, journal = {Science of computer programming}, number = {12}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0167-6423}, doi = {10.1016/j.scico.2010.11.013}, pages = {1194 -- 1209}, year = {2011}, abstract = {Context-oriented programming (COP) provides dedicated support for defining and composing variations to a basic program behavior. A variation, which is defined within a layer, can be de-/activated for the dynamic extent of a code block. While this mechanism allows for control flow-specific scoping, expressing behavior adaptations can demand alternative scopes. For instance, adaptations can depend on dynamic object structure rather than control flow. We present scenarios for behavior adaptation and identify the need for new scoping mechanisms. The increasing number of scoping mechanisms calls for new language abstractions representing them. We suggest to open the implementation of scoping mechanisms so that developers can extend the COP language core according to their specific needs. Our open implementation moves layer composition into objects to be affected and with that closer to the method dispatch to be changed. We discuss the implementation of established COP scoping mechanisms using our approach and present new scoping mechanisms developed for our enhancements to Lively Kernel.}, language = {en} } @book{KleineHirschfeldBracha2011, author = {Kleine, Matthias and Hirschfeld, Robert and Bracha, Gilad}, title = {An abstraction for version control systems}, series = {Technische Berichte des Hasso-Plattner-Instituts f{\"u}r Softwaresystemtechnik an der Universit{\"a}t Potsdam}, journal = {Technische Berichte des Hasso-Plattner-Instituts f{\"u}r Softwaresystemtechnik an der Universit{\"a}t Potsdam}, number = {54}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-158-5}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-55629}, publisher = {Universit{\"a}t Potsdam}, pages = {77}, year = {2011}, abstract = {Versionsverwaltungssysteme (VCS) erm{\"o}glichen es Entwicklern, {\"A}nderungen an Softwareartifakten zu verwalten. VCS werden mit Hilfe einer Vielzahl verschiedener Werkzeuge bedient, wie z.\,B. graphische Front-ends oder Kommandozeilenwerkzeuge. Es ist w{\"u}nschenswert mit einzelnen solcher Werkzeuge unterschiedliche VCS bedienen zu k{\"o}nnen. Bislang hat sich jedoch keine Abstraktion f{\"u}r Versionsverwaltungssysteme durchgesetzt, mit deren Hilfe solche Werkzeuge erstellt werden k{\"o}nnen. Stattdessen implementieren Werkzeuge zur Interaktion mit mehreren VCS ad-hoc L{\"o}sungen. Diese Masterarbeit stellt Pur vor, eine Abstraktion {\"u}ber Versionsverwaltungskonzepte. Mit Hilfe von Pur k{\"o}nnen Anwendungsprogramme entwickelt werden, die mit mehreren Versionsverwaltungssystemen interagieren k{\"o}nnen. Im Rahmen dieser Arbeit wird eine Implementierung dieser Abstraktion bereitgestellt und mit Hilfe eines Anwendungsprogramms validiert.}, language = {en} } @article{SteinertHirschfeld2012, author = {Steinert, Bastian and Hirschfeld, Robert}, title = {Applying design knowledge to programming}, year = {2012}, language = {en} } @article{HirschfeldPerscheidHaupt2012, author = {Hirschfeld, Robert and Perscheid, Michael and Haupt, Michael}, title = {Explicit use-case representation in object-oriented programming languages}, series = {ACM SIGPLAN notices}, volume = {47}, journal = {ACM SIGPLAN notices}, number = {2}, publisher = {Association for Computing Machinery}, address = {New York}, issn = {0362-1340}, doi = {10.1145/2168696.2047856}, pages = {51 -- 60}, year = {2012}, abstract = {Use-cases are considered an integral part of most contemporary development processes since they describe a software system's expected behavior from the perspective of its prospective users. However, the presence of and traceability to use-cases is increasingly lost in later more code-centric development activities. Use-cases, being well-encapsulated at the level of requirements descriptions, eventually lead to crosscutting concerns in system design and source code. Tracing which parts of the system contribute to which use-cases is therefore hard and so limits understandability. In this paper, we propose an approach to making use-cases first-class entities in both the programming language and the runtime environment. Having use-cases present in the code and the running system will allow developers, maintainers, and operators to easily associate their units of work with what matters to the users. We suggest the combination of use-cases, acceptance tests, and dynamic analysis to automatically associate source code with use-cases. We present UseCasePy, an implementation of our approach to use-case-centered development in Python, and its application to the Django Web framework.}, language = {en} } @book{AppeltauerHirschfeld2012, author = {Appeltauer, Malte and Hirschfeld, Robert}, title = {The JCop language specification : Version 1.0, April 2012}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-193-6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60208}, publisher = {Universit{\"a}t Potsdam}, pages = {iv, 48}, year = {2012}, abstract = {Program behavior that relies on contextual information, such as physical location or network accessibility, is common in today's applications, yet its representation is not sufficiently supported by programming languages. With context-oriented programming (COP), such context-dependent behavioral variations can be explicitly modularized and dynamically activated. In general, COP could be used to manage any context-specific behavior. However, its contemporary realizations limit the control of dynamic adaptation. This, in turn, limits the interaction of COP's adaptation mechanisms with widely used architectures, such as event-based, mobile, and distributed programming. The JCop programming language extends Java with language constructs for context-oriented programming and additionally provides a domain-specific aspect language for declarative control over runtime adaptations. As a result, these redesigned implementations are more concise and better modularized than their counterparts using plain COP. JCop's main features have been described in our previous publications. However, a complete language specification has not been presented so far. This report presents the entire JCop language including the syntax and semantics of its new language constructs.}, language = {en} }