Visual Replacements: Cross-Language Domain-Specific Representations in Structured Editors

To help developers work at the level of abstraction of their choice, some editors offer to replace parts of source code with domain-specific representations (DSRs). Typically, such replacements are language-specific and optimized to limited use-cases. In this paper, we extend a general-purpose structured editor with visual replacements , a mechanism to replace code of any programming language with DSRs. A visual replacement consists of language-dependent queries to map arbitrary syntax trees and a language-independent DSR of differing abstraction and interactivity, ranging from simple images to graphical user interfaces that modify source code. Our extension synchronizes source code and DSR automatically, while ensuring that language support such as autocompletion and error checking work even inside a replacement. We demonstrate the use and applicability of the replacement mechanism in three case studies.