| In this thesis, we present an extensible type system for component-based design. Fundamentally, a type system detects incompatibilities at component interfaces. Incompatibility may happen at two different levels: data types and dynamic behavior. Accordingly, the type system presented in this thesis also has two parts.; Our type system supports both the primitive types and structured types, such as arrays and records. The addition of structured types makes the type lattice infinite, and requires an extension on the format of the inequality constraints.; The data-level type system has been implemented in Ptolemy II, which is a component-based design environment. Our implementation is modular. In particular, the CPO and lattice support, including the algorithm for solving inequality constraints, are implemented as a generic infrastructure that is not bound to one particular type lattice. Type definition and type checking are implemented in separate packages and have been fully integrated with Ptolemy II.; To describe the dynamic behavior of components and perform compatibility check, we extend the concepts of conventional type system to behavioral level and capture the dynamic interaction between components, such as the communication protocols the components use to pass messages. (Abstract shortened by UMI.)... |
