John Altidor

Me by the CS building

School of Computer Science
University of Massachusetts
jaltidor [at] cs [dot] umass [dot] edu

I recently completed my Ph.D. in Computer Science at UMass Amherst. My advisors were Yannis Smaragdakis and Jack Wileden. I am now a research scientist at BBN Technologies.

Research Interests


Subtyping with Generics

Many modern languages have support for parametric polymorphism such as Generics in Java. Parametric polymorphism enhances the readability, maintainability, and safety of programs. Subtyping promotes software reuse by allowing code to be applied to a larger set of terms. Integrating both approaches is far from trivial. For example, consider a Generic interface List<E>, where E is a type parameter, List is a parametric type (generic), and instances of E can be read from or written to instances of List<E>. Even if Dog is a subtype of Animal, it is not safe to assume that List<Dog> (a list of Dogs) is a List<Animal> (a list of Animals). Existing variance mechanisms enable greater subtyping between parametric types but can be difficult to use and suffer from various deficiencies. This project aims at providing programming language mechanisms to better support subtyping with parametric polymorphism.

Feature-Based CAD System Interoperability

Computer-aided design (CAD) systems are used to create virtual representations of physical objects (e.g. cars, planes). Interoperability of CAD systems is a major problem when enabling information integration in a collaborative engineering environment. Existing standard CAD data formats such as IGES and STEP do not preserve feature information during CAD data exchange. Hence, they do not enable the modification, extension, and ability to perform higher-level functionality on imported CAD models from other CAD systems. This project aims at enabling higher-level CAD data exchange.

  • CAD Data Exchange Software Project: (www)


Other Documents

Teaching Experience


Professional Events Attended

Conferences and Workshops

Summer Schools

NSF Center for e-Design IAB Meetings