100 research outputs found

    Towards Improving Interface Modularity in Legacy Java Software through Automated Refactoring

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    The skeletal implementation pattern is a software design pattern consisting of defining an abstract class that provides a partial interface implementation. However, since Java allows only single class inheritance, if implementers decide to extend a skeletal implementation, they will not be allowed to extend any other class. Also, discovering the skeletal implementation may require a global analysis. Java 8 enhanced interfaces alleviate these problems by allowing interfaces to contain (default) method implementations, which implementers inherit. Java classes are then free to extend a different class, and a separate abstract class is no longer needed; developers considering implementing an interface need only examine the interface itself. We argue that both these benefits improve software modularity, and discuss our ongoing work in developing an automated refactoring tool that would assist developers in taking advantage of the enhanced interface feature for their legacy Java software

    μ-DSU:A Micro-Language Based Approach to Dynamic Software Updating

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    Today software systems play a critical role in society’s infrastructures and many are required to provide uninterrupted services in their constantly changing environments. As the problem domain and the operational context of such software changes, the software itself must be updated accordingly. In this paper we propose to support dynamic software updating through language semantic adaptation; this is done through use of micro-languages that confine the effect of the introduced change to specific application features. Micro-languages provide a logical layer over a programming language and associate an application feature with the portion of the programming language used to implement it. Thus, they permit to update the application feature by updating the underlying programming constructs without affecting the behaviour of the other application features. Such a linguistic approach provides the benefit of easy addition/removal of application features (with a special focus on non-functional features) to/from a running application by separating the implementation of the new feature from the original application, allowing for the application to remain unaware of any extensions. The feasibility of this approach is demonstrated with two studies; its benefits and drawbacks are also analysed

    Covariant Conversions (CoCo): A Design Pattern for Type-Safe Modular Software Evolution in Object-Oriented Systems

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    Software evolution is an essential challenge for all software engineers, typically addressed solely using code versioning systems and language-specific code analysis tools. Most versioning systems view the evolution of a system as a directed acyclic graph of steps, with independent branches that could be merged. What these systems fail to provide is the ability to ensure stable APIs or that each subsequent evolution represents a cohesive extension yielding a valid system. Modular software evolution ensures that APIs remain stable, which is achieved by ensuring that only additional methods, fields, and data types are added, while treating existing modules through blackbox interfaces. Even with these restrictions, it must be possible to add new variations, fields, and methods without extensive duplication of prior module code. In contrast to most literature, our focus is on ensuring modular software evolution using mainstream object-oriented programming languages, instead of resorting to novel language extensions. We present a novel CoCo design pattern that supports type-safe covariantly overridden convert methods to transform earlier data type instances into their newest evolutionary representation to access operations that had been added later. CoCo supports both binary methods and producer methods. We validate and contrast our approach using a well-known compiler construction case study that other researchers have also investigated for modular evolution. Our resulting implementation relies on less boilerplate code, is completely type-safe, and allows clients to use normal object-oriented calling conventions. We also compare CoCo with existing approaches to the Expression Problem. We conclude by discussing how CoCo could change the direction of currently proposed Java language extensions to support closed-world assumptions about data types, as borrowed from functional programming

    Building music with lego bricks and Raspberry Pi

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    In this paper, a system to build music in an intuitive and accessible way, with Lego bricks, is presented. The system makes use of the new powerful and cheap possibilities that technology ofers for making old things in a new way. The Raspberry Pi is used to control the system and run the necessary algorithms, customized Lego bricks are used for building melodies, custom electronic designs, software pieces and 3D printed parts complete the items employed. The system designed is modular, it allows creating melodies with chords and percussion or just melodies or perform as a beatbox or a melody box. The main interaction with the system is made using Lego-type building blocks. Tests have demonstrated its versatility and ease of use, as well as its usefulness in music learning for both children and adults.Funding for open access publishing: Universidad Málaga/CBUA This publication is part of the project PDC2021-120997-C33 funded by MCIN/AEI/10.13039/501100011033, and European Union “NextGenerationEU/PRTR”. This publication is part of the project PID2021-123207NB-I00 funded by MCIN/AEI/10.13039/501100011033/FEDER, UE. This work was done at Universidad de Málaga, Campus de Excelencia Internacional Andalucia Tech. Funding for open access charge: Universidad de Málaga/CBUA

    WeaFQAs: A Software Product Line Approach for Customizing and Weaving Efficient Functional Quality Attributes

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    Fecha de Lectura de Tesis: 10 de julio de 2018Los atributos de calidad funcionales (FQA) son aquellos que tienen una clara implicación en la funcionalidad del sistema, es decir, existen unos componentes específicos que deben ser incorporados a la arquitectura software del sistema para satisfacer sus requisitos de atributos de calidad. Ejemplos de FQAs son seguridad, usabilidad, o persistencia. Modelar estos atributos es una tarea compleja. Por un lado, se componen de muchas características relacionadas, por ejemplo seguridad está compuesto, entre otros, por autenticación, confidencialidad y encriptación. Tienen dependencias entre ellos, por ejemplo, seguridad puede ser requerido por usabilidad o persistencia. Por otro lado, tienen muchos puntos de variabilidad: una aplicación concreta puede requerir autenticación y control de acceso mientras que otra puede necesitar sólo encriptación. Además, su funcionalidad suele estar dispersa afectando a varios componentes del sistema en desarrollo. El objetivo de esta tesis es definir una línea de productos software orientada a aspectos que permita: (1) modelar las similitudes y la variabilidad de los FQAs desde las primeras etapas del proceso de desarrollo, (2) gestionar las dependencias existentes entre los FQAs, (3) independizar el modelado de los FQAs de la arquitectura de la aplicación afectada, (4) configurar los FQAs en base a los requisitos de cada aplicación teniendo además en cuenta propiedades no funcionales como el rendimiento y el consumo energético de cada solución, (5) incorporar las configuraciones a la arquitectura de la aplicación de manera automática; y (6) gestionar la evolución de los FQAs cuando los requisitos cambien en el futuro. Como resultado se ha definido WeaFQAs, un proceso software para gestionar los FQAs que cubre todos los puntos mencionados. Se han realizado y comparado dos instanciaciones de WeaFQAs usando diferentes lenguajes de variabilidad y de modelado, además de proporcionar soporte con una herramienta basada en el lenguaje CVL

    Using Spoofax to Support Online Code Navigation

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    Spoofax is a language workbench. A Spoofax language specification generally includes name resolution: the analysis of bindings between definitions and references. When browsing code in the specified language using Spoofax, the bindings appear as hyperlinks, supporting precise name-based code navigation. However, Spoofax cannot be used for browsing code in online repositories. This paper is about a toolchain that uses Spoofax to generate hyperlinked twins of code repositories. These generated artefacts support the same precise code navigation as Spoofax, and can be browsed online. The technique has been prototyped on the CBS (Component-Based Semantics) specification language developed by the PLanCompS project, but could be used on any language after specifying its name resolution in Spoofax

    The Way We Were: Structural Operational Semantics Research in Perspective

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    This position paper on the (meta-)theory of Structural Operational Semantic (SOS) is motivated by the following two questions: (1) Is the (meta-)theory of SOS dying out as a research field? (2) If so, is it possible to rejuvenate this field with a redefined purpose? In this article, we will consider possible answers to those questions by first analysing the history of the EXPRESS/SOS workshops and the data concerning the authors and the presentations featured in the editions of those workshops as well as their subject matters. The results of our quantitative and qualitative analyses all indicate a diminishing interest in the theory of SOS as a field of research. Even though `all good things must come to an end', we strive to finish this position paper on an upbeat note by addressing our second motivating question with some optimism. To this end, we use our personal reflections and an analysis of recent trends in two of the flagship conferences in the field of Programming Languages (namely POPL and PDLI) to draw some conclusions on possible future directions that may rejuvenate research on the (meta-)theory of SOS. We hope that our musings will entice members of the research community to breathe new life into a field of research that has been kind to three of the authors of this article.Comment: In Proceedings EXPRESS/SOS2023, arXiv:2309.0578

    Synthesizing Functional Reactive Programs

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    Functional Reactive Programming (FRP) is a paradigm that has simplified the construction of reactive programs. There are many libraries that implement incarnations of FRP, using abstractions such as Applicative, Monads, and Arrows. However, finding a good control flow, that correctly manages state and switches behaviors at the right times, still poses a major challenge to developers. An attractive alternative is specifying the behavior instead of programming it, as made possible by the recently developed logic: Temporal Stream Logic (TSL). However, it has not been explored so far how Control Flow Models (CFMs), as synthesized from TSL specifications, can be turned into executable code that is compatible with libraries building on FRP. We bridge this gap, by showing that CFMs are indeed a suitable formalism to be turned into Applicative, Monadic, and Arrowized FRP. We demonstrate the effectiveness of our translations on a real-world kitchen timer application, which we translate to a desktop application using the Arrowized FRP library Yampa, a web application using the Monadic threepenny-gui library, and to hardware using the Applicative hardware description language ClaSH.Comment: arXiv admin note: text overlap with arXiv:1712.0024

    News, networks and users in the Hybrid Media system: report

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    95 p.Descargas previas 4 The technological, economic and credibility crises that media organisations have been simultaneously grappling with during this period have coincided with the rise of new actors and platforms with a vast potential for global communication, such as Google and Facebook, and the empowerment of audiences ready and able to generate content on an unprecedented scale, especially via social networks. While conventional newspapers have attempted to cope with the ongoing transformation of the news market by implementing tepid innovations, their bid to maintain control over the defining aspects of journalistic practice has been constantly checked by the entry of new platforms, the proliferation of new spaces for debate and audiences’ growing appetite for sharing selfgenerated content.News, networks and users in the Hybrid Media System (Newsnet) is a research project funded by the Spanish Ministry of Science, Innovation and Universities (RTI2018-095775-B-C41/42/44

    News, networks and users in the Hybrid Media system: report

    Get PDF
    95 p.Descargas previas 4 The technological, economic and credibility crises that media organisations have been simultaneously grappling with during this period have coincided with the rise of new actors and platforms with a vast potential for global communication, such as Google and Facebook, and the empowerment of audiences ready and able to generate content on an unprecedented scale, especially via social networks. While conventional newspapers have attempted to cope with the ongoing transformation of the news market by implementing tepid innovations, their bid to maintain control over the defining aspects of journalistic practice has been constantly checked by the entry of new platforms, the proliferation of new spaces for debate and audiences’ growing appetite for sharing selfgenerated content.News, networks and users in the Hybrid Media System (Newsnet) is a research project funded by the Spanish Ministry of Science, Innovation and Universities (RTI2018-095775-B-C41/42/44
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