Towards a Periodic Table of Connectors

Connectors are the glue for combining components and are a critical aspect of software architecture design. Providing a framework similar in spirit to that of the periodic table of chemical elements, this work strives to obtain a set of high level canonical properties that can describe all possible connectors and allow operations to be de ned over them. Connector factorization obtains a new connector characterized by the common subset of primitive properties of a given set of connectors. Also, a connector can be specialized by adding primitive properties to the set that characterizes it. This approach leads us to the notion of connector class. A connector class can be seen as a connector that does not dene a criteria for a set of properties, these properties are viewed as optional by the class. In addition, we extend operations of specialization and factorization of connectors over classes. By explicitly de ning the set of primitive properties to be included in the periodic table, it is also possible to explore the connector universe by contriving connectors as new combinations of properties. As in Mendeleev's original table, the periodic table of connector properties will require many re nements and additions. For instance, if one can characterize two known distinct connectors with the same set of properties, the table must be revised. Examples of properties that could be included in the initial table are, Broadcast, Reliable, Typed and Synchronous. The ideas presented in this work are not completely new. [1] the main goal is to understand operations over connectors but higher order connectors are used instead of reusing properties. [2] proposes and a rst sketch of the periodic table analogy only that it is based on low level properties not distinguishing between connectors and components. This work is in a preliminary stage and it would be very important to de ne a formal semantics for properties and to formalize this framework and its operations. But formal semantics may be di cult to establish until a complete understanding of relevant properties and an interesting canonical set has been de ned. This paper is a rst step in this direction.