Metaparse Compile-time parsing with template metaprogramming

Metaparse is a C++ template metaprogramming library for generating parsers, which are template metaprograms themselves parsing strings at C++ compile-time. Parsers built with Metaparse take free-formed strings as input and parse them at compile-time, thus it is possible to build a parser and apply it in the same session of compilation. The C++11 standard provides constexpr, a construct for executing algorithms at compile-time. We present the connection between metaprogramming and constexpr and utilise it to minimise the syntactical overhead of the input processed by the parsers. Thus Metaparse is capable to solve a wide variety of tasks – from applying syntactical sugars for existing metaprograms to DSL integrations. An accurate error reporting helps Metaparse users to detect parsing errors. All solutions presented in this paper are implemented as an open source library and are available for the reader.