Deriving fluent internal domain-specific languages from grammars

Abstract

A prime decision of engineering domain-specific languages (DSLs) is implementing these as external DSLs or internal DSLs. Agile language engineering benefits from easily switching between both shapes to provide rapidly developed prototypes before settling on a specific syntax. This switching, however, is rarely feasible due to the effort of re-implementing language tooling for both shapes. Current research in software language engineering focuses either on internal DSLs or external DSLs. We conceived a concept to automatically derive customizable internal DSLs from grammars that operate on the same abstract syntax as the external DSL. This supports reusing tooling (such as model checkers or code generators) between both shapes. We realized our concept with the MontiCore language workbench and Groovy as host language for internal DSLs. This concept is applicable to many grammar-based language definition