Lightweight, flexible object-oriented generics
Abstract
The support for generic programming in modern object-oriented programming languages is awkward and lacks desirable expressive power. We introduce an expressive genericity mechanism that adds expressive power and strengthens static checking, while remaining lightweight and simple in common use cases. Like type classes and concepts, the mechanism allows existing types to model type constraints retroactively. For expressive power, we expose models as named constructs that can be defined and selected explicitly to witness constraints; in common uses of genericity, however, types implicitly witness constraints without additional programmer effort. Models are integrated into the object-oriented style, with features like model generics, model-dependent types, model enrichment, model multimethods, constraint entailment, model inheritance, and existential quantification further extending expressive power in an object-oriented setting. We introduce the new genericity features and show that common generic programming idioms, including current generic libraries, can be expressed more precisely and concisely. The static semantics of the mechanism and a proof of a key decidability property can be found in an associated technical report.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 03, 2015
- Source ID
- 10.1145/2813885.2738008
Entities
People
- Andrew C. Myers
- Barbara Liskov
- Guido Salvaneschi
- Matthew C. Loring
- Yizhou Zhang
Organizations
- Cornell University
- European Research Council
- Federal Ministry of Research, Technology and Space
- Massachusetts Institute of Technology
- National Science Foundation
- Office of Naval Research
- Technical University of Darmstadt