Programming languages that enable the mobility of code over the network are becoming widely used for building distributed applications. In this talk I will introduce a family of languages that adopt functions as the main programming abstraction and support code mobility through the mobility of functions between remote sites.

Functional languages are known for their well-understood computational models and their amenability to formal reasoning. In the context of sequential computation, some functional languages have been able to combine strong expressive power with security by exploiting static type systems. In the context of computation with mobile functions, static type systems can play a similar role. When extended with effects and other annotations, types prove to be useful in reasoning about the dynamic behavior of mobile code.

I will focus on a collection of problems which arise from the heterogeneity of distributed systems in terms of the nature of computing devices, security requirements of the information flowing through them and the trust level of users. I will discuss type-based solutions to these problems and present type systems for static estimation of mobile values, distributed-call tracking and controlling the flow of values in a system.

DATE: April 26, 2002, Friday @ 16:30

PLACE: EA-409