Interaction - Oriented Programming

This dissertation describes the design and implementation of a general-purpose object-oriented (OO) programming language, Classages. The novel object model of Classages gives programmers refined control over modeling the interactions inside OO software, with inspirations drawn from human sociology. Key innovations include the language constructs of Mixers and Connectors as encapsulation-enforceable interfaces for specifying bi-directional interaction behaviors, and a novel type system called Pedigree Types to help programmers organize the object heap into a hierarchy reflecting the fundamental principle of hierarchical decomposition. Important properties of the language, including type soundness, hierarchy shape enforcement, and alias protection, are formally established and proved. A prototype compiler is implemented. The object model of Classages sets a significant departure from the familiar one taken by Smalltalk, Java, C++, and C#. Its simple, expressive, and rigorously defined core enriches the theoretical foundations of OO languages. From the perspective of software engineering, the Classages language is particularly good at controlling software complexity, a crucial goal in modern software development. Advisor: Prof. Scott Smith, The Johns Hopkins University Readers: Prof. Michael Hicks, University of Maryland, College Park Prof. Scott Smith, The Johns Hopkins University Prof. Andreas Terzis, The Johns Hopkins University