V1E: A Kernel for Domain-specific Textual Variability Modelling Languages

v1e is a language kernel for textual variability modelling built on top of the language-development system DjDSL. As a language kernel,v1e provides a minimal but extensible set of abstractions to implement families of domain-specific languages for textual variability modelling. v1e provides for a small and versatile abstract syntax to encode feature models using multiplicity constraints and canonical semantics. v1e offers built-in analysis support, such as configuration validation, by maintaining internal BDD representations. A derived language becomes realised as a collection of extensions dependent on the language kernel. v1e is designed to behighly extensible and embeddable, e.g., as a dynamic library or as aREPL shell. In this paper, we showcase a selected derived languageand the design decisions involved: a kernel implementation of TVL on top of v1e. We conclude the paper by pointing out current limitations (e.g., representing attributed variability models) and future directions (e.g., analysis support beyond BDD).