1,721,033 research outputs found
Eating Your Own Dog Food: WebDSL Case Studies to Improve Academic Workflows
No full textSDF, Stratego and Spoofax provide a platform for development of domain-specific programming languages. On this platform, the WebDSL project started out as a case study in language engineering, and grew into a reliable tool for rapid prototyping and continuous development of web applications. Our team led by Eelco Visser develops and operates several web applications to support academic workflows. EvaTool governs the process of course quality control, importing questionnaire data, and providing lecturers and education directors with a platform to discuss and agree on improvements. WebLab is an online learning management system with a focus on programming education, with support for lab work and digital exams, used by over 40 courses. Conf Researchr is a domain-specific content management system for creating and hosting integrated websites for conferences with multiple co-located events, used by all ACM SIGPLAN and SIGSOFT conferences. MyStudyPlanning is an application for composition of individual study programs by students and verification of those programs by the exam board, used by multiple faculties at the Delft University of Technology. These tools served as practical case studies for applying the research, and ensure the continued development of the underlying platform.Programming Language
Using Spoofax to Support Online Code Navigation
No full textSpoofax 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.Programming Language
Renamingless Capture-Avoiding Substitution for Definitional Interpreters
No full textSubstitution is a common and popular approach to implementing name binding in definitional interpreters. A common pitfall of implementing substitution functions is variable capture. The traditional approach to avoiding variable capture is to rename variables. However, traditional renaming makes for an inefficient interpretation strategy. Furthermore, for applications where partially-interpreted terms are user facing it can be confusing if names in uninterpreted parts of the program have been changed. In this paper we explore two techniques for implementing capture avoiding substitution in definitional interpreters to avoid renaming.Programming Language
Getting Things Done: The Eelco Way
Get PDFEelco Visser (1966-2022) was a leading member of the department of Software Technology (ST) of the faculty of Electrical Engineering Mathematics, and Computer Science (EEMCS) of Delft University of Technology. He had a profound influence on the educational programs in computer science at TU Delft, built a highly successful Programming Languages Group from the ground up, and used his research results to develop widely used tools and services that have been used by thousands of students and researchers for more than a decade. He realized all these successes not just alone, but in close collaboration with a range of people, who he convinced to follow his lead. In this short reflection, I look back at his achievements, and at the way in which he worked with others to bring ambitious ideas to successful reality
Scope Graphs: The Story so Far
Get PDFStatic name binding (i.e., associating references with appropriate declarations) is an essential aspect of programming languages. However, it is usually treated in an unprincipled manner, often leaving a gap between formalization and implementation. The scope graph formalism mitigates these deficiencies by providing a well-defined, first-class, language-parametric representation of name binding. Scope graphs serve as a foundation for deriving type checkers from declarative type system specifications, reasoning about type soundness, and implementing editor services and refactorings. In this paper we present an overview of scope graphs, and, using examples, show how the ideas and notation of the formalism have evolved. We also briefly discuss follow-up research beyond type checking, and evaluate the formalism
Extraction of Structured Programs from Specification Proofs
Get PDFWe present a method using an extended logical system for obtaining programs from specifications written in a sublanguage of CASL. These programs are ?correct? in the sense that they satisfy their specifications. The technique we use is to extract programs from proofs in formal logic by techniques due to Curry and Howard. The logical calculus, however, is novel because it adds structural rules corresponding to the standard ways of modifying specifications: translating (renaming), taking unions, and hiding signatures. Although programs extracted by the Curry-Howard process can be very cumbersome, we use a number of simplifications that ensure that the programs extracted are in a language close to a standard high-level programming language. We use this to produce an executable refinement of a given specification and we then provide a method for producing a program module that maximally respects the original structure of the specification. Throughout the paper we demonstrate the technique with a simple example
Towards Modular Compilation Using Higher-Order Effects
Get PDFCompilers transform a human readable source language into machine readable target language. Nanopass compilers simplify this approach by breaking up this transformation into small steps that are more understandable, maintainable, and extensible. We propose a semantics-driven variant of the nanopass compiler architecture exploring the use a effects and handlers to model the intermediate languages and the transformation passes, respectively. Our approach is fully typed and ensures that all cases in the compiler are covered. Additionally, by using an effect system we abstract over the control flow of the intermediate language making the compiler even more flexible. We apply this approach to a minimal compiler from a language with arithmetic and let-bound variables to a string of pretty printed X86 instructions. In the future, we hope to extend this work to compile a larger and more complicated language and we envision a formal verification framework from compilers written in this style
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Theory and Practice of Action Semantics
Get PDFAction Semantics is a framework for the formal descriptionof programming languages. Its main advantage over other frameworksis pragmatic: action-semantic descriptions (ASDs) scale up smoothly torealistic programming languages. This is due to the inherent extensibilityand modifiability of ASDs, ensuring that extensions and changes tothe described language require only proportionate changes in its description.(In denotational or operational semantics, adding an unforeseenconstruct to a language may require a reformulation of the entire description.)After sketching the background for the development of action semantics,we summarize the main ideas of the framework, and provide a simpleillustrative example of an ASD. We identify which features of ASDsare crucial for good pragmatics. Then we explain the foundations ofaction semantics, and survey recent advances in its theory and practicalapplications. Finally, we assess the prospects for further developmentand use of action semantics.The action semantics framework was initially developed at the Universityof Aarhus by the present author, in collaboration with David Watt(University of Glasgow). Groups and individuals scattered around fivecontinents have since contributed to its theory and practice
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