Rascal, 10 years later

When we designed the first version of Rascal in 2009, we jokingly promised ourselves to only write a single paper on the language itself, and see it as vehicle for research from then on,—that one paper became the SCAM 2009 article, now awarded with the SCAM most influential paper award. Since then, Rascal has evolved significantly, and has been successfully applied in research, education, and industry. This extended abstract gives an overview of the impact of Rascal over the last 10 years, and looks at current and future developments

Towards Multilingual Programming Environments

Software projects consist of different kinds of artifacts: build files, configuration files, markup files, source code in different software languages, and so on. At the same time, however, most integrated development environments (IDEs) are focused on a single (programming) language. Even if a programming environment supports multiple languages (e.g., Eclipse), IDE features such as cross-referencing, refactoring, or debugging, do not often cross language boundaries. What would it mean for programming environment to be truly multilingual? In this short paper we sketch a vision of a system that integrates IDE support across language boundaries. We propose to build this system on a foundation of unified source code models and metaprogramming. Nevertheless, a number of important and hard research questions still need to be addressed

Towards multilingual programming environments

Software projects consist of different kinds of artifacts: build files, configuration files, markup files, source code in different software languages, and so on. At the same time, however, most integrated development environments (IDEs) are focused on a single (programming) language. Even if a programming environment supports multiple languages (e.g., Eclipse), IDE features such as cross-referencing, refactoring, or debugging, do not often cross language boundaries. What would it mean for programming environment to be truly multilingual? In this short paper we sketch a vision of a system that integrates IDE support across language boundaries. We propose to build this system on a foundation of unified source code models and metaprogramming. Nevertheless, a number of important and hard research questions still need to be addressed

The State of the Art in Language Workbenches. Conclusions from the Language Workbench Challenge

Language workbenches are tools that provide high-level mechanisms for the implementation of (domain-specific) languages. Language workbenches are an active area of research that also receives many contributions from industry. To compare and discuss existing language workbenches, the annual Language Workbench Challenge was launched in 2011. Each year, participants are challenged to realize a given domain-specific language with their workbenches as a basis for discussion and comparison. In this paper, we describe the state of the art of language workbenches as observed in the previous editions of the Language Workbench Challenge. In particular, we capture the design space of language workbenches in a feature model and show where in this design space the participants of the 2013 Language Workbench Challenge reside. We compare these workbenches based on a DSL for questionnaires that was realized in all workbenches

Deriving modernity signatures of codebases with static analysis

This paper addresses the problem of determining the modernity of software systems by analysing the use of new language features and their adoption over time. We propose the concept of modernity signatures to estimate the age of a codebase, naturally adjusted for maintenance practices, such that the modernity of a regularly updated system would be above that of a more recently created one which neglects current features and best practices. This can provide insights into coding practices, codebase health and the evolution of software languages. We present case studies on PHP and Python code, demonstrating the effectiveness of modernity signatures in determining the age of a codebase without executing the code or performing extensive human inspection. The paper describes the technical implementation details of generating the modernity signature for both of these languages, including the use of existing tools like the PHP parser and Vermin. The findings suggest that modernity signatures can aid developers in many ways from choosing whether to use a system or how to approach its maintenance, to assessing usefulness of a language feature, thus providing a valuable tool for source code analysis and manipulation

Static, lightweight includes resolution for PHP

International audienceDynamic languages include a number of features that are challenging to model properly in static analysis tools. In PHP, one of these features is the include expression, where an arbitrary expression provides the path of the file to include at runtime. In this paper we present two complementary analyses for statically resolving PHP includes, one that works at the level of individual PHP files and one targeting PHP programs, possibly consisting of multiple scripts. To evaluate the effectiveness of these analyses we have applied the first to a corpus of 20 open-source systems, totaling more than 4.5 million lines of PHP, and the second to a number of programs from a subset of these systems. Our results show that, in many cases, includes can be either resolved to a specific file or a small subset of possible files, enabling better IDE features and more advanced program analysis tools for PHP

Engineering Language-Parametric End-User Programming Environments for DSLs

Human-computer communication can be achieved through different interfaces such as Graphical User Interfaces (GUIs), Tangible User Interfaces (TUIs), command-line interfaces, and programming languages. In this thesis, we used some of these inter- faces; however, we focused on programming languages which are artificial languages consisting of instructions written by humans and executed by computers. In order to create these programs, humans use specialized tools called programming environments that offer a set of utilities that ease human-computer communication. When creating programs, users must learn the language’s syntax and get acquainted with the pro- gramming environment. Unfortunately, programming languages usually offer a single user interface or syntax, which is not ideal considering different types of users with varied backgrounds and expertise will use it. Given the increasing number of people performing any kind of programming activity, it is important to offer different inter- faces depending on the programming task and the background of the users. However, from the language engineering point of view, offering multiple user interfaces for the same language is expensive, and if we specifically consider Domain-Specific Languages (DSLs), it is even more expensive given their audience and development teams’ size. Therefore, we study how to engineer different user interfaces for DSLs in a practical way.This thesis presents different mechanisms to engineer different language-parametric programming environments for end-users. These mechanisms rely heavily on reusing existing language components for existing languages or helping language engineers define these interfaces for new languages. We mainly studied four technological spaces, namely, Grammarware, Computational Notebooks, Block-based environments, and Projec- tional editors. We present three different language-parametric interfaces for interacting with DSLs, namely computational notebooks, projectional editors, and block-based editors. These interfaces offer different user experiences and rely upon different technological spaces. Different notations are associated with different technological spaces; for in- stance, grammarware is associated with text files, while block-based environments are associated with Blockly and JavaScript files. Therefore, to provide different notations for their languages, we have to "space travel" so that language engineers can select the most appropriate technological space and interface for their target audience. To support this, we defined grammarware as a common starting point to allow traveling to different technological spaces (e.g., computational notebooks space, projectional editors space, or block-based space). Based on this idea, we developed three tools that allowed language engineers to generate different interfaces for their DSLs based on a grammar definition of the language. Our results show that it is possible to generate these different user interfaces and decrease the effort required to create these. However, additional research is required to improve the usability of the generated interfaces and make the generation of these interfaces more flexible so that users’ data can be used as part of the generated interfaces

Modeling and Analysis of SQL Queries in PHP Systems

PHP is a common language used for creating dynamic websites. These websites often include the use of databases to store data, with embedded SQL queries constructed within the PHP code and executed through the use of database access libraries. One of these libraries is the original MySQL library that, despite not being supported in current versions of PHP, is still widely used in existing PHP code. As a first step towards developing program comprehension and transformation tools for PHP systems that use this library, this research presents a query modeling tool that models embedded SQL queries in PHP systems and an empirical study conducted through analysis of these models. A main focus of this study was to establish common patterns developers use to construct SQL queries and to extract information about their occurrences in actual PHP systems. Using these patterns, the parts of queries that are generally static, and the parts that are often computed at runtime were extracted. For dynamically computed query parts, we also extracted data about which PHP language features are used to construct them. Finally, information about which clauses most often differ based on control flow was extracted as well as counts for how often each SQL query type and SQL clause is used in practice. We believe this information is useful for future work on building program understanding and transformation tools to renovate PHP code using database libraries