How Clean Is Your Sandbox?

Bidirectional transformations (

bx

) constitute an emerging mechanism for maintaining the consistency of interdependent sources of information in software systems. Researchers from many different communities have recently investigated the use of

bx

to solve a large variety of problems, including relational view update, schema evolution, data exchange, database migration, and model co-evolution, just to name a few. Each community leveraged and extended different theoretical frameworks and tailored their use for specific sub-problems. Unfortunately, the question of how these approaches actually relate to and differ from each other remains unanswered. This question should be addressed to reduce replicated efforts among and even within communities, enabling more effective collaboration and fostering cross-fertilization. To effectively move forward, a systematization of these many theories and systems is now required. This paper constitutes a first, humble yet concrete step towards a unified theoretical framework for a tractable and relevant subset of

bx

approaches and tools. It identifies, characterizes, and compares tools that allow the

incremental

definition of bidirectional mappings between software artifacts. Identifying similarities between such tools yields the possibility of developing practical tools with wide-ranging applicability; identifying differences allows for potential new research directions, applying the strengths of one tool to another whose strengths lie elsewhere.