Section: New Results

Data Driven Systems

Modular composition of Guarded Attribute Grammars

Participants : Éric Badouel

We investigate how the role of a user in a distributed collaborative systems modelled by a Guarded Attribute Grammar can be associated with a domain specific language (DSL) encapsulating a specific domain knowledge (expertise) and defining a set of services (a language-oriented approach). These DSLs communicate through service calls (a service-oriented approach).

Language oriented programming is an approach to software composition based on domain specific languages (DSL) dedicated to specific aspects of an application domain. In order to combine such languages we embed them into a host language (namely Haskell, a strongly typed higher-order lazy functional language). A DSL is then given by an algebraic type, whose operators are the constructors of abstract syntax trees. Such a multi-sorted signature is associated to a polynomial functor. An algebra for this functor tells us how to interpret the programs. Using Bekić's Theorem we defined in [13] a modular decomposition of algebras that leads to a class of parametric multi-sorted signatures, associated with regular functors, allowing for the modular design of DSLs.

In [12] we have addressed the problem of component reuse in the context of service-oriented programming and more specifically for the design of user-centric distributed collaborative systems modelled by Guarded Attribute Grammars. Following the contract-based specification of components we developp an approach to an interface theory for the roles in a collaborative system in three stages: we define a composition of interfaces that specifies how the component behaves with respect to its environement, we introduce an implementation order on interfaces and finally a residual operation on interfaces characterizing the systems that, when composed with a given component, can complement it in order to realize a global specification.