Reference attribute grammars (RAGs) have reached a level of maturity where they are supported by several tools, and have gained traction in both academic and industrial language tool development. However, despite a lot of accumulated knowledge of how to best develop RAGs in practice, there is limited support to guide practitioners.

In this paper, we address this issue by focusing on one RAG tool, JastAdd, and by defining principles and patterns for development of RAGs with this tool. We evaluate the proposed principles and patterns with an exploratory empirical study with 14 practitioners, with a mix of beginners and experienced users from both academia and industry. The results indicate that the principles and patterns capture the practice of developing JastAdd RAGs well, help practitioners to become aware of useful patterns, and provide a common language to more efficiently reason about the practice of developing JastAdd RAGs.