[Colloq] Thesis Defense: Foundations for Behavioral Contracts

[Jessica Biron]

The College of Computer and Information Science presents a PhD thesis 
defense : 

Speaker: Christos Dimoulas 

Date: Wednesday December 12, 2012 at 14:30 
Location: 366 WVH 

Title: Foundations for Behavioral Contracts 

Abstract: 

Contracts are a popular mechanism for enhancing the interface of 
components. In the world of first-order functions, programmers embrace 
contracts because they write them in a familiar language and easily 
understand them as a pair of a pre-condition and a post-condition. In a 
higher-order world, contracts offer the same expressiveness to 
programmers but their meaning subtly differs from the familiar 
first-order notion. For instance, it is unclear what the behavior of 
dependent contracts for higher-order functions or of contracts for 
mutable data should be. As a consequence, it is difficult to design 
monitoring systems for such higher-order worlds. 

In response to this problem, we investigate complete monitors, a formal 
framework for deciding if a contract system is correct. The intuition 
behind the framework is that a correct contract system should: 
-- mediate the exchange of values between contracted components 
-- and blame correctly in case of contract violations. 
The framework reveals flaws in the semantics for dependent contracts 
from the literature and suggests a natural fix. In addition, we 
demonstrate the usefulness of the framework for language design with a 
language with contracts for mutable data and a language that mixes typed 
and untyped imperative programs. The final contribution is the provably 
correct design of a novel form of contracts, dubbed options contracts, 
that mix contract checking with random and probabilistic checking. 


Committee: 
Matthias Felleisen 
Amal Ahmed 
Mitch Wand 
Cormac Flanagan (UCSC) 





Jessica Biron 
Administrative Assistant – Office of the Dean and CCIS Development 
College of Computer and Information Science 
Northeastern University 
202 West Village H 
617-373-5204 
bironje at ccs.neu.edu 
http://www.ccs.neu.edu/