Section: Software

Moca

Participant : Frédéric Blanqui [ correspondant ] .

Moca is developed by Pierre Weis (INRIA Rocquencourt) and Frédéric Blanqui.

It is a general construction functions generator for OCaML [40] data types with invariants.

Moca allows the high-level definition and automatic management of complex invariants for data types. In addition, Moca 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:

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

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

Algebraic relations are primitive, so that Moca ensures the correctness of their treatment. By contrast, the general rewrite rules are under the programmer's responsibility, so that the desired properties must be verified by a programmer's proof before compilation (including for completeness, termination, and confluence of the resulting term rewriting system).

Algebraic invariants are specified by using keywords denoting equational theories like commutativity and associativity. Moca generates construction functions that allow each equivalence class to be uniquely represented by their canonical value.

Moca is distributed under QPL on http://moca.inria.fr/ .