Proceedings of the First International Workshop on Bidirectional Transformations (BX 2012) Language Evolution, Metasyntactically

Abstract: Currently existing syntactic definitions employ many different notations (usually dialects of EBNF) with slight deviations among them, which prevent efficient automated processing. When changes in such notation are required either due to maintenance activities such as correction or evolution, or because a grammar collection is written in a different notation than the one required by the grammarware toolkit, we speak of metalanguage evolution: i.e., a special language evolution scenario when the language itself does not necessarily evolve, but the notation in which it is written, does. Notational changes need to be propagated to different levels, such as to parsers that used to work with the old notation, to grammars of those notations that served as explanation material, and finally to the existing grammarbase. The solution proposed in this paper, relies on composition of a notation specification and expressing notation changes as transformations of that specification. These transformation steps are coupled to changes in the notation grammar (i.e., grammar for grammars) and to changes in other grammars written in the original notation. This paper explains the general setup of such an infrastructure, with links to the prototypical implementation of the solution

First International Workshop on Bidirectional Transformations (BX 2012): Preface

Bidirectional transformations (bx) are a mechanism for maintaining the consistency of two (or perhaps more) related sources of information. Such sources can be databases, software models, documents, or their abstract models like graphs or trees. BX are an emerging topic in a wide range of research areas with prominent presence at top conferences in different fields. The methodologies used for bx range from classical program transformation to graph transformation techniques, from ad-hoc techniques for data synchronization to the development of domain-specific languages and their integration. The First International Workshop on Bidirectional Transformations (BX 2012) established a dedicated venue for bx in all relevant areas. It was initiated by the participants of the Dagstuhl Seminar "Bidirectional Transformations" (bx) in Germany 2011, which continued the GRACE International Meeting on Bidirectional Transformations held in Japan 2008.The workshop BX 2012 took place at the Tallinn University of Technology,Estonia on the 25th of March 2012, as a satellite event of ETAPS 2012, the European Joint Conferences on Theory and Practice of Software

Pending Evolution of Grammars

The classic approach to grammar manipulation is based on instant processing of grammar edits, which limits the kinds of grammar evolution scenarios that can be expressed with it. Treating transformation preconditions as guards poses limitations on concurrent changes of the same grammar, on reuse of evolution scripts, on expressing optionally executed steps, on batch processing and optimization of them, etc. We propose an alternative paradigm of evolution, where a transformation can be scheduled for later execution based on its precondition. This kind of extreme evolution can be useful for expressing scenarios that are impossible to fully automate within the classic or the negotiated transformation paradigms

Cotransforming Grammars with Shared Packed Parse Forests

SPPF (shared packed parse forest) is the best known graph representation of a parse forest (family of related parse trees) used in parsing with ambiguous/conjunctive grammars. Systematic general purpose transformations of SPPFs have never been investigated and are considered to be an open problem in software language engineering. In this paper, we motivate the necessity of having a transformation operator suite for SPPFs and extend the state of the art grammar transformation operator suite to metamodel/model (grammar/graph) cotransformations

Guided Grammar Convergence. Full Case Study Report. Generated by converge::Guided

This report is meant to be used as auxiliary material for the guided grammar convergence technique proposed earlier as problem-specific improvement in the topic of convergence of grammars. It contains a narrated MegaL megamodel, as well as full results of the guided grammar convergence experiment on the Factorial Language, with details about each grammar source packaged in a readable form. All formulae used within this document, are generated automatically by the convergence infrastructure in order to avoid any mistakes. The generator source code and the source of the introduction text can be found publicly available in the Software Language Processing Suite repository