Modular Programming through Precise Typing of Open Recursion

The Hong Kong University of Science and Technology
Department of Computer Science and Engineering


MPhil Thesis Defence


Title: "Modular Programming through Precise Typing of Open Recursion"

By

Mr. Andong FAN


Abstract:

We present a new variation of object-oriented programming built around three 
simple and orthogonal constructs: classes for storing object state, interfaces 
for expressing object types, and mixins for reusing and overriding 
implementations. We show that the latter can be made uniquely expressive by 
leveraging a novel feature that we call precisely-typed open recursion. This 
features uses this and super annotations to express the requirements of any 
given partial method implementation on the types of respectively the current 
object and the inherited definitions. Crucially, the fact that mixins do not 
introduce types nor subtyping relationships means they can be composed even 
when the overriding and overridden methods have incomparable types. Together 
with advanced type inference and structural typing support provided by the 
MLscript programming language, we show that this enables an elegant and 
powerful solution to the Expression Problem.


Date:                   Monday, 29 July 2024

Time:                   9:00am - 11:00am

Venue:                  Room 5501
                        Lifts 25/26

Chairman:               Dr. Jiasi SHEN

Committee Members:      Dr. Lionel PARREAUX (Supervisor)
                        Prof. Shing-Chi CHEUNG