Type Specialization and Coordination

                           Franz Puntigam
      Technische Universität Wien, Institut für Computersprachen
	 Argentinierstraße 8, A-1040 Vienna, Austria, Europe
	      e-mail: franz@complang.tuwien.ac.at

Declarative models and language concepts for the coordination in parallel
and distributed systems attract increasing attention because of their
simplicity and expressiveness. In this paper, type specialization is
proposed as a declarative, object-oriented programming and coordination
model. A simple execution mechanism repeatedly specializes types of
entities (variables) and thereby collects knowledge about the objects
represented by these entities. Concurrently running specialization processes
communicate through logically shared entities and by writing specialization
requests (which create further processes) to a shared black-board.
The entities' specialization degrees determine if and when a specialization
request is executable atomically. Coordination is usually implicit in the
data dependencies of the program and need not be specified explicitly.