MacoCaml is a new design and implementation of compile-time computation for OCaml that features a novel combination of phase separation and quotation-based staging. Together with OCaml’s existing facilities — sophisticated data types, algebraic effects, a rich module language — these features provide a flexible and expressive system for generative programming.

This interactive tutorial illustrates the development of a generative program using MacoCaml, and outlines how the key meta-theoretical properties of type soundness and phase distinction offer practical benefits for programmers.