Introducing Reflection in Architecture Description Languages

Abstract

This document describes the structure of PiLar, an Architectural Description Language based on concepts from the field of Reflection, following a proposal suggested in previous work. First, motivations and ideas behind its design are outlined. Next, the language is divided in two parts: a declarative Structural Language, which makes possible to define an architecture’s static skeleton; and an imperative Dynamic Language, which appears as a set of constraining rules written in a concurrent language. Both languages are intertwined with the reification concept, which has a reflective origin. Its meaning and consequences are commented in detail. After this, the language’s formal semantics are informally described; it is conceived as a system of concurrent processes, communicating by means of channels. It is argued that this semantics fits perfectly with architectural concepts. Finally, a solution for the classical problem of the Dining Philosophers is included as an example, to show how this Adl describes the dynamic evolution in a system. The paper concludes emphasizing the generality and usefulness of the language.