The Design and Implementation of Bloqqi - A Feature-Based Diagram Programming Language

This dissertation presents the design and implementation of a new block diagram programming language, Bloqqi, for building control systems with focus on variability. The language has been developed in collaboration with industry with the goal of reducing engineering time and improving reuse of functionality.When building a control system for a plant, there are typically different variants of the same base functionality. A plant may have several variants of a tank, for example, one variant with heating and another one without. This dissertation presents novel language mechanisms for describing this kind of variability, based on diagram inheritance. For instance, Bloqqi supports specifying what features, like heating, the base functionality can have. These specifications are then used to automatically derive smart-editing support in the form of a feature-based wizard. In this wizard, the user can select what features the base functionality should have, and code is generated corresponding to these features. The new language mechanisms allow feature-based libraries to be created and extended in a modular way.This dissertation presents techniques for implementing rich graphical editors with smart editing support based on semantic analysis. A prototype compiler and graphical editor have been implemented for the language, using the semantic formalism reference attribute grammars (RAGs). RAGs allow tools to share the semantic specifications, which makes it possible to modularly extend the compiler with support for advanced semantic feedback to the user of the graphical editor

Abstract-Syntax-Driven Development of Oberon-0 Using YAJCo

YAJCo is a tool for the development of software languages based on an annotated language model. The model is represented by Java classes with annotations defining their mapping to concrete syntax. This approach to language definition enables the abstract syntax to be central point of the development process, instead of concrete syntax. In this paper a case study of Oberon-0 programming language development is presented. The study is based on the LTDA Tool Challenge and showcases details of abstract and concrete syntax definition using YAJCo, as well as implementation of name resolution, type checking, model transformation and code generation. The language was implemented in modular fashion to demonstrate language extension mechanisms supported by YAJCo

Simpl: valdkonnaspetsiifiliste keelte loomise tööriist ettevõttetarkvara arendamiseks

Domain specific languages (DSLs) are languages designed with the specific purpose of developing or configuring part of a software system using concepts that are close to those of the system's application domain. Documented benefits of DSLs include increased development productivity, flexibility and maintainability, as well as separation of business and technical aspects allowing in some cases non-technical stakeholders to closely partake in the software development process. DSLs however comes at a potentially non-negligible cost, that of creating and maintaining DSL implementations. These costs can be reduced by means of specialized tools that support the creation of parsers, analyzers, code generators, pretty-printers, and other functions associated with a DSL. This thesis deals with the problem of enabling cost-effective DSL-based development in the context of Enterprise Information Systems (EIS). EISs are generally built using application frameworks and middleware. Accordingly, it must be possible to package the DSL implementation as a module that can be called from either the build system or from the enterprise system itself. Additionally, the DSL tool should be accessible to enterprise system developers with little or no expertise in development of programming languages and supporting tools, such as Integrated Development Environments. The central contribution of the thesis is Simpl, a DSL toolkit designed to meet the needs of enterprise software development. Simpl builds up on top of existing tools and programming languages, and introduces the following features: a grammar description language that supports the generation of both the parser and the data types for representing abstract syntax trees; support for lexer states that add context-sensitivity to lexer in a controlled manner; a pretty-printing library; an IDE framework; and an integration layer that combines all components into a single whole and minimizes the need for boilerplate code.Valdkonnaspetsiifilised programmeerimiskeeled (domain specific language, DSL) on keeled, mis on välja töötatud kasutamiseks mingis konkreetses rakendusvaldkonnas. Spetsialiseerumine võimaldab DSLis kasutada konstruktsioone, mis sobivad hästi antud valdkonna mõistete esitamiseks. DSLide kasutamine annab võrreldes üldotstarbeliste keeltega mitmeid eeliseid nagu näiteks kõrgem tarkvaraarenduse efektiivsus ning paindlikum ja hästi hooldatav lõpptulemus. Samuti saavad DSLide abil tarkvaraarenduses osaleda ka isikud, kelle tehnilised oskused ei ole piisavad üldotstarbelistes keeltes programmeerimiseks, näiteks süsteemianalüütikud, lõppkasutajad jne. Teisest küljest kaasnevad DSLide kasutamisega ka kulutused DSLide välja töötamiseks ning haldamiseks. DSL-põhist tarkvaraarendust saab muuta efektiivsemaks, kasutades DSLide realiseerimiseks spetsiaalseid tööriistu. Käesoleva väitekirja fookuses on kuluefektiivne DSLide kasutamisel põhinev ettevõttetarkvara arendus. Ettevõtteinfosüsteemid realiseeritakse tüüpiliselt raamistike ja valmiskomponentide abil. Seega peab olema võimalik pakendada DSLi realisatsioon moodulina, mida on võimalik välja kutsuda kas ehitussüsteemist või EISist endast. DSLi realiseerimise tööriist peab sobima kasutamiseks ka tarkvaraarendajatele, kellel ei ole kogemusi programmeerimiskeelte ja neid toetavate vahendite arendamiseks. Töö olulisemad väited on järgmised. Esiteks, ettevõttetarkvara arendamisel on oma spetsiifika, mis seab nõudeid DSLidele ning nende realiseerimiseks kasutatavatele tööriistadele. Teiseks, enamik populaarseid tööriistu, eriti integreeritud tööriistu, mis katavad ära kogu DSLi realiseerimiseks vajaliku tegevuste spektri, ei rahulda vähemalt osaliselt neid nõudeid. Kolmandaks, me demonstreerime, et on võimalik töötada välja DSL tööriist, mis on sobiv ettevõtteinfosüsteemide arendamiseks ning mis pakub olemasolevate tööriistadega võrreldavat kasutusmugavust.valdkonnaspetsiifilised keeledettevõttedhaldusinfosüsteemiddomain specific languagesenterprisesmanagement information system

First-class features

Magdeburg, Univ., Fak. für Informatik, Diss., 2011von Sagar Sunkl

Constructing Hybrid Incremental Compilers for Cross-Module Extensibility with an Internal Build System

Context: Compilation time is an important factor in the adaptability of a software project. Fast recompilation enables cheap experimentation with changes to a project, as those changes can be tested quickly. Separate and incremental compilation has been a topic of interest for a long time to facilitate fast recompilation. Inquiry: Despite the benefits of an incremental compiler, such compilers are usually not the default. This is because incrementalization requires cross-cutting, complicated, and error-prone techniques such as dependency tracking, caching, cache invalidation, and change detection. Especially in compilers for languages with cross-module definitions and integration, correctly and efficiently implementing an incremental compiler can be a challenge. Retrofitting incrementality into a compiler is even harder. We address this problem by developing a compiler design approach that reuses parts of an existing non-incremental compiler to lower the cost of building an incremental compiler. It also gives an intuition into compiling difficult-to-incrementalize language features through staging. Approach: We use the compiler design approach presented in this paper to develop an incremental compiler for the Stratego term-rewriting language. This language has a set of features that at first glance look incompatible with incremental compilation. Therefore, we treat Stratego as our critical case to demonstrate the approach on. We show how this approach decomposes the original compiler and has a solution to compile Stratego incrementally. The key idea on which we build our incremental compiler is to internally use an incremental build system to wire together the components we extract from the original compiler. Knowledge: The resulting compiler is already in use as a replacement of the original whole-program compiler. We find that the incremental build system inside the compiler is a crucial component of our approach. This allows a compiler writer to think in multiple steps of compilation, and combine that into a incremental compiler almost effortlessly. Normally, separate compilation \`a la C is facilitated by an external build system, where the programmer is responsible for managing dependencies between files. We reuse an existing sound and optimal incremental build system, and integrate its dependency tracking into the compiler. Grounding: The incremental compiler for Stratego is available as an artefact along with this article. We evaluate it on a large Stratego project to test its performance. The benchmark replays edits to the Stratego project from version control. These benchmarks are part of the artefact, packaged as a virtual machine image for easy reproducibility. Importance: Although we demonstrate our design approach on the Stratego programming language, we also describe it generally throughout this paper. Many currently used programming languages have a compiler that is much slower than necessary. Our design provides an approach to change this, by reusing an existing compiler and making it incremental within a reasonable amount of time

Modular and type-safe definition of Attribute Grammars with AspectAG

AspectAG is a Haskell-embedded domain-specific language (EDSL) that encodes first-class attribute grammars (AGs). AspectAG ensures the wellformedness of AGs at compile time by using extensible records and predicates encoded using old-fashioned type-level programming features, such as multiparameter type classes and functional dependencies. AspectAG suffers the usual drawbacks of EDSLs: when type errors occur they usually do not deliver error messages that refer to domain terms, but to the host language. Often, implementation details of the EDSL are leaked in those messages. The use of type-level programming techniques makes the situation worse since type-level abstraction mechanisms are quite poor. Additionally, old-fashioned type-level programs are untyped at type-level, which is inconsistent with the general approach of strongly-typed functional programming. By using modern Haskell extensions and techniques we propose a reworked version of AspectAG that tackles those weaknesses. New AG definitions are safer, both at the level of types and at the level of kinds. Furthemore, a set of identified domain-specific errors are reported with DSL-oriented messages. To achieve this, we define and use a framework for manipulating type errors that can be used in any EDSL. We show the pragmatics of AspectAG by defining languages and extending them both with new syntax and semantics. We use MateFun, a purelyfunctional language used to teach mathematics as a case study.AspectAG es un lenguaje de dominio específico embebido (EDSL) que codifica gramáticas de atributos (AGs) como ciudadanos de primera clase. AspectAG garantiza la buena formación de las AGs en tiempo de compilación por medio del uso de registros extensibles y predicados, codificados gracias al uso de características antiguas de programación a nivel de tipos, como clases multiparámetro y dependencias funcionales. AspectAG sufre las desventajas usuales de los EDSLs: cuando ocurren errores de tipado, los mensajes de error reportados no se expresan en términos del dominio, sino del lenguaje anfitrión. También es usual que detalles de implementación del EDSL se vean filtrados en estos mensajes. El uso de técnicas de programación a nivel de tipos agrava la situación porque los mecanismos de abstracción a nivel de tipos son pobres. Ademas, las técnicas de programación a nivel de tipos usadas en AspectAG son esencialmente no tipadas, lo que es inconsistente con nuestro enfoque de tipado fuerte. Usando extensiones modernas al sistema de tipos de Haskell, proponemos una nueva versión de la biblioteca AspectAG, abordando los problemas antes mencionados. Las nuevas definiciones de AGs son mas seguras tanto a nivel de tipado como a nivel de kinds (tipado a nivel de tipos). Ademas, un conjunto identificado de errores específicos del dominio son reportados con mensajes referentes al mismo. Para lograr esto, definimos y utilizamos un framework para manipular errores de tipado, que puede ser aplicado a cualquier EDSL. Mostramos la pragmática de AspectAG definiendo lenguajes y extendiéndoles con nueva sintaxis y con nueva semántica. Utilizamos el lenguaje MateFun, un lenguaje funcional puro utilizado para enseñar matemáticas como caso de estudio

A JastAdd implementation of Oberon-0

As a part of the LDTA 2011 Tool Challenge, we implemented a compiler for the language Oberon-0 using the metacompilation tool JastAdd. In this paper, we report on this implementation, and reflect on aspects of it such as ease of use, modularity, and safety