Modular Choreographies: Bridging Alice and Bob Notation to Java.

We present Modular Choreographies, a new choreographic programming language that features modular functions. Modular Choreographies is aimed at simplicity: its communication abstraction follows the simple tradition from the “Alice and Bob” notation. We develop a compiler toolchain that translates choreographies into modular Java libraries, which developers can use to participate correctly in choreographies. The key novelty is to compile through the Choral language, which was previously proposed to define object-oriented choreographies: our toolchain compiles Modular Choreographies to Choral, and then leverages the existing Choral compiler to generate Java code. Our work is the first to bridge the simplicity of traditional choreographic programming languages with the requirement of generating modular libraries in a mainstream language (Java).