SCHOOL: a Small Chorded Object-Oriented Language

Chords are a declarative synchronisation construct based on the Join calculus, available in the programming language Cω. Compared with synchronisation constructs in most imperative languages, chords promise development of programs that are more succinct, easier to read, and easier to reason about. However, to our knowledge, chords have no formal model in an object-oriented setting. In this paper we suggest SCHOOL, a formal model for an object-oriented language with chords. We give an operational semantics and type system, and prove soundness of the type system. SCHOOL is minimal, supporting only classes, inheritance and chords. To prove that SCHOOL is sufficient, we define SCHOOL+F, an extension of SCHOOL with fields. We develop an encoding of SCHOOL+F into SCHOOL, and prove soundness and completness of the encoding with respect to the type system and the operational semantics.