Dynamically Typed Languages

The languages discussed in this special issue have a long history, which is perhaps why some have had several different names over the years. One such language is Lisp, the second-oldest programming language. For years, many somewhat dismissively described languages such as Lisp as "scripting languages." Today, we more commonly refer to them as dynamically typed languages, typified by Python and Ruby, and their impact is arguably greater than ever. This issue highlights the practical uses of such languages and shows how they're frequently a vehicle for innovation in the development sphere. This article is part of a special issue on dynamically typed languages

Domain-specific languages

Domain-Specific Languages are used in software engineering in order to enhance quality, flexibility, and timely delivery of software systems, by taking advantage of specific properties of a particular application domain. This survey covers terminology, risks and benefits, examples, design methodologies, and implementation techniques of domain-specific languages as used for the construction and maintenance of software systems. Moreover, it covers an annotated selection of 75 key publications in the area of domain-specific languages

Software languages engineering: experimental evaluation

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia InformáticaDomain-Specific Languages (DSLs) are programming languages that offer, through appropriate notation and abstraction, still enough an expressive control over a particular problem domain for more restricted use. They are expected to contribute with an enhancement of productivity, reliability, maintainability and portability, when compared with General Purpose Programming Languages (GPLs). However, like in any Software Product without passing by all development stages namely Domain Analysis, Design, Implementation and Evaluation, some of the DSLs’ alleged advantages may be impossible to be achieved with a significant level of satisfaction. This may lead to the production of inadequate or inefficient languages. This dissertation is focused on the Evaluation phase. To characterize DSL community commitment concerning Evaluation, we conducted a systematic review. The review covered publications in the main fora dedicated to DSLs from 2001 to 2008, and allowed to analyse and classify papers with respect to the validation efforts conducted by DSLs’ producers, where have been observed a reduced concern to this matter. Another important outcome that has been identified is the absence of a concrete approach to the evaluation of DSLs, which would allow a sound assessment of the actual improvements brought by the usage of DSLs. Therefore, the main goal of this dissertation concerns the production of a Systematic Evaluation Methodology for DSLs. To achieve this objective, has been carried out the major techniques used in Experimental Software Engineering and Usability Engineering context. The proposed methodology was validated with its use in several case studies, whereupon DSLs evaluation has been made in accordance with this methodology

Domain-specific languages for ecological modelling

The primary concern of an ecological modeller is to construct a model that is mathematically correct and that correctly represents the essence of a natural system. When models are published as software, it is moreover in the hope of capturing an audience who will use and appreciate the model. For that purpose, the model software must be provided with an intuitive, flexible and expressive user interface. A graphical user interface (GUI) is the commonly accepted norm but in this review we suggest, that a domain-specific language (DSL) in many cases would provide as good an interface as a GUI, or even better. We identified only 13 DSLs that have been used in ecological modelling, revealing a general ignorance of DSLs in the ecological modelling community. Moreover, most of these DSLs were not formulated for the ecological modelling domain but for the broader, generic modelling domain. We discuss how DSLs could possibly fill out a vacant niche in the dominant paradigm for ecological modelling, which is modular, object-oriented and often component-based. We conclude that ecological modelling would benefit from a wider appreciation of DSL methodology. Especially, there is a scope for new DSLs operating in the rich concepts of ecology, rather than in the bland concepts of modelling generics

When and how to develop domain-specific languages

Domain-specific languages (DSLs) are languages tailored to a specific application domain. They offer substantial gains in expressiveness and ease of use compared with general purpose programming languages in their domain of application. DSL development is hard, requiring both domain knowledge and language development expertise. Few people have both. Not surprisingly, the decision to develop a DSL is often postponed indefinitely, if considered at all, and most DSLs never get beyond the application library stage. While many articles have been written on the development of particular DSLs, there is very limited literature on DSL development methodologies and many questions remain regarding when and how to develop a DSL. To aid the DSL developer, we identify patterns in the decision, analysis, design, and implementation phases of DSL development. Our patterns try to improve on and extend earlier work on DSL design patterns, in particular by Spinellis (2001). We also discuss domain analysis tools and language development systems that may help to speed up DSL development. Finally, we state a number of open problems