A Core Model for Choreographic Programming

We investigate the foundations of Choreographic Programming, a paradigm for writing concurrent programs that are deadlock free by construction, guided by the notion of computation. We start by introducing Minimal Choreographies (MC), a language that includes only the essential primitives of the paradigm. MC is minimal wrt Turing completeness: it implements all computable functions, and restricting its syntax breaks this property. Our methodology yields a natural notion of computation for choreographies, which can be used to generate concurrent implementations of independent computations automatically. Finally, we show that a Turing complete fragment of MC can be correctly projected to a process calculus (synthesis), which is thus both deadlock free and Turing complete.