Departmental Papers (CIS)

Date of this Version

May 2008

Document Type

Journal Article


Postprint version. Published in ACM Transactions on Programming and Languages, Volume 30, Issue 3, Article No. 14, May 2008.
Publisher URL:


This paper defines AspectML, a typed functional, aspect-oriented programming language. The main contribution of AspectML is the seamless integration of polymorphism, run-time type analysis and aspect-oriented programming language features. In particular, AspectML allows programmers to define type-safe polymorphic advice using pointcuts constructed from a collection of polymorphic join points. AspectML also comes equipped with a type inference algorithm that conservatively extends Hindley-Milner type inference. To support first-class polymorphic point-cut designators, a crucial feature for developing aspect-oriented profiling or logging libraries, the algorithm blends the conventional Hindley-Milner type inference algorithm with a simple form of local type inference. We give our language operational meaning via a type-directed translation into an expressive type-safe intermediate language. Many complexities of the source language are eliminated in this translation, leading to a modular specification of its semantics. One of the novelties of the intermediate language is the definition of polymorphic labels for marking control-flow points. When a set of labels is assembled as a pointcut, the type of each label is an instance of the type of the pointcut.


design, languages, security, theory, aspect-oriented programming, functional languages, parametric and ad-hoc polymorphism, type systems, type inference



Date Posted: 16 July 2008

This document has been peer reviewed.