Domain-Specific Language Integration with C++ Template Metaprogramming

Abstract

Domain specific language integration has to provide the right balance between the expressive power of the DSL and the implementation and maintenance cost of the applied integration techniques. External solutions may perform poorly as they depend on third party tools which should be implemented, tested and then maintained during the whole lifetime of the project. Ideally a self-contained solution can minimize third-party dependencies. The authors propose the use of C++ template metaprograms to develop a domain specific language integration library based on only the standard C++ language features. The code in the domain specific language is given as part of the C++ source code wrapped into C++ templates. When the C++ source is compiled, the C++ template metaprogram library implementing a full-featured parser infrastructure is executed. As the authors’ approach does not require other tool than a standard C++ compiler, it is highly portable. To demonstrate their solution, the chapter implements a type-safe printf as a domain specific language. The library is fully implemented and downloadable as an open source project.