Multifocal : a strategic bidirectional transformation language for XML schemas

• Author(s): Pacheco, Hugo ; Cunha, Alcino
• Date: 2012
• Persistent ID: http://hdl.handle.net/1822/24674
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Coupled transformations; Bidirectional transformations; Two-level transformations; Strategic programming; XML
• Document Type: Article
• Language: English

Description

Lenses are one of the most popular approaches to define bidirectional transformations between data models. However, writing a lens transformation typically implies describing the concrete steps that convert values in a source schema to values in a target schema. In contrast, many XML-based languages allow writing structure-shy programs that manipulate only specific parts of XML documents without having to specify the behavior for the remaining structure. In this paper, we propose a structure-shy bidirectional two-level transformation language for XML Schemas, that describes generic type-level transformations over schema representations coupled with value-level bidirectional lenses for document migration. When applying these two-level programs to particular schemas, we employ an existing algebraic rewrite system to optimize the automatically-generated lens transformations, and compile them into Haskell bidirectional executables. We discuss particular examples involving the generic evolution of recursive XML Schemas, and compare their performance gains over non-optimized definitions.