Masato Takeichi

Towards automatic model synchronization from model transformations

The metamodel techniques and model transformation techniques provide a standard way to represent and transform data, especially the software artifacts in software development. However, after a transformation is applied, the source model and the target model usually co-exist and evolve independently. How to propagate modifications across models in different formats still remains as an open problem.n In this paper we propose an automatic approach to synchronizing models that are related by model transformations. Given a unidirectional transformation between metamodels, we can automatically synchronize models in the metamodels by propagating modifications across the models. We have implemented a model synchronization system supporting the Atlas Transformation Language (ATL) and have successfully tested our implementation on several ATL transformation examples in the ATL web site.

A programmable editor for developing structured documents based on bidirectional transformations

This paper presents an application of bidirectional transformation to the design and implementation of a novel editor supporting interactive refinement in the development of structured documents. The user performs a sequence of editing operations on a view of the document, and the editor automatically derives an efficient and reliable document source and a transformation that produces the document view. The editor is unique in its programmability, in the sense that transformations can be obtained through editing operations. It uses the view-updating technique developed in the database community and a new bidirectional transformation language that can describe not only the relationship between the document source and its view, but also the data dependency in the view.

Supporting automatic model inconsistency fixing

Modern development environments often involve models with complex consistency relations. Some of the relations can be automatically established through fixing procedures. When users update some parts of the model and cause inconsistency, a fixing procedure dynamically propagates the update to other parts to fix the inconsistency. Existing fixing procedures are manually implemented, which requires a lot of efforts and the correctness of a fixing procedure is not guaranteed.n In this paper we propose a new language, Beanbag, to support the development of fixing procedures. A Beanbag program defines and checks a consistency relation similarly to OCL, but the program can also be executed in a fixing mode, taking user updates on the model and producing new updates to make the model satisfy the consistency relation. In this way Beanbag significantly eases the development of fixing procedures. In addition, a Beanbag program is also guaranteed to be correct with respect to the three correctness properties we define. We evaluate Beanbag over a set of MOF and UML consistency relations and the result shows that Beanbag is useful in practice.

Supporting Parallel Updates with Bidirectional Model Transformations

Model-driven software development often involves several related models. When models are updated, the updates need to be propagated across all models to make them consistent. A bidirectional model transformation keeps two models consistent by updating one model in accordance with the other. However, it does not work when the two models are modified at the same time. n nIn this paper we propose a new algorithm that wraps any bidirectional transformation into a synchronizer with the help of a model difference approach. The synchronizer enables parallel updates by taking the two original models, the two updated models as input and producing two new models where the updates are synchronized. We also examine the requirements for synchronizing parallel updates, and demonstrate that our algorithm satisfies the requirements if the bidirectional transformation satisfies the correctness property and the hippocraticness property. Implementation of our algorithm showed that it works well in a runtime management framework in practical cases.

Program calculation in coq

Program calculation, being a programming technique that derives programs from specification by means of formula manipulation, is a challenging activity. It requires human insights and creativity, and needs systems to help human to focus on clever parts of the derivation by automating tedious ones and verifying correctness of transformations. Different from many existing systems, we show in this paper that Coq, a popular theorem prover, provides a cheap way to implement a powerful system to support program calculation, which has not been recognized so far. We design and implement a set of tactics for the Coq proof assistant to help the user to derive programs by program calculation and to write proofs in calculational form. The use of these tactics is demonstrated through program calculations in Coq based on the theory of lists.

Type-based specialization of xml transformations

It is often convenient to write a function and apply it to a specific input. However, a program developed in this way may be inefficient to evaluate and difficult to analyze due to its generality. In this paper, we propose a technique of new specialization for a class of XML transformations, in which no output of a function can be decomposed or traversed. Our specialization is type-based in the sense that it uses the structures of input types; types are described by regular hedge grammars and subtyping is defined set-theoretically. The specialization always terminates, resulting in a program where every function is fully specialized and only accepts its rigid input. We present several interesting applications of our new specialization, especially for injectivity analysis.

A web service architecture for bidirectional XML updating

A Web service architecture is described for bidirectional XML updating. The updating mechanism exploits the power of bidirectional transformation so that users can update remote XML data by editing a view on the local machine that is generated by a transformation of the XML data. This architecture consists of three tiers: data viewer clients, a bidirectional transformation engine, and content servers accessible through the Internet. Due to the use of standard Web service technologies, the data viewer clients and content servers can be easily replaced with ones chosen by the user. Users can use this architecture to implement their own applications that exploit the power of bidirectional transformation without the burden of installing and maintaining a bidirectional language package.

Consistent Web site updating based on bidirectional transformation

A transformation-based Web site can keep the content of a Web site consistent by furnishing a single database and a set of transformation programs, each of which generates a Web page. However, when someone notices an error or stale content on a Web page in this style of Web site construction, the Web site maintainer must access a possibly huge database to update the corresponding content. This paper proposes a new approach to Web site construction based on bidirectional transformation, together with a practical updating system, Vu-X. Because of the bidirectionality of the transformations, users can directly modify a generated Web page rather than accessing the database and the modification is automatically reflected in the database. The Vu-X system is also implemented as a Web server so that users can edit it in WYSIWYG style on their Web browsers. Since the Vu-X system employs a bidirectional transformation language Bi-X to describe bidirectional transformations, we can obtain both transformations only by specifying a transformation in one direction.