Code Less to Code More: Streamlining Language Server Protocol and type system development for language families

Developing editing support for L languages in E editors is complex and time-consuming. Some languages do not provide dedicated editors, while others offer a single native editor. The language server protocol (LSP) reduces the language-editor combinations L×E to L+E, where a single language server communicates with editors via LSP plugins. However, overlapping implementations of linguistic components remain an issue. Existing language workbenches struggle with modularity, reusability, and leveraging type systems for language server generation. In this work, we propose: (i) Typelang, a family of domain-specific languages for modular, composable, and reusable type system implementation, (ii) a modular language server generation process, producing servers for languages built in a modular workbench, (iii) the variant-oriented programming paradigm and a cross-artifact coordination layer to manage interdependent software variants, and (iv) an LSP plugin generator, reducing E to 1 by automating plugin creation for multiple editors. To simplify editing support for language families, each language artifact integrates its own Typelang variant, used to generate language servers. This reduces combinations to T×1, where T=L represents the number of type systems. Further reuse of language artifacts across languages lowers this to N×1, where N<