Section: Software and Platforms


Moca is a construction functions generator for OCaml data types with invariants.

It allows the high-level definition and automatic management of complex invariants for data types. In addition, it provides the automatic generation of maximally shared values, independently or in conjunction with the declared invariants.

A relational data type is a concrete data type that declares invariants or relations that are verified by its constructors. For each relational data type definition, Moca compiles a set of construction functions that implements the declared relations.

Moca supports two kinds of relations:

  • predefined algebraic relations (such as associativity or commutativity of a binary constructor),

  • user-defined rewrite rules that map some pattern of constructors and variables to some arbitrary user's define expression.

The properties that user-defined rules should satisfy (completeness, termination, and confluence of the resulting term rewriting system) must be verified by a programmer's proof before compilation. For the predefined relations, Moca generates construction functions that allow each equivalence class to be uniquely represented by their canonical value.

Moca is distributed under QPL. It is developed by Frédéric Blanqui, Pierre Weis (EPI Pomdapi) and Richard Bonichon (CEA).