MiniMAO1: Investigating the Semantics of Proceed

		by Curtis Clifton and Gary T. Leavens

			      TR #05-01b

		   January 2005, revised March 2005

This paper describes MiniMAO1, a core aspect-oriented calculus. Unlike
previous aspect-oriented calculi, it allows around advice to change the
target object of an advised operation before proceeding. MiniMAO1 
accurately models the ways AspectJ allows changing the target object, 
e.g., at call join points. Practical uses for changing the target object 
using advice include proxies and other wrapper objects. 

In addition to accurate modeling of bindings for around advice, MiniMAO1 
has several other features that make it suitable for the study of aspect-
oriented mechanisms, such as those found in AspectJ. Like AspectJ, the 
calculus consists of an imperative, object-oriented base language plus 
aspect-oriented extensions. MiniMAO1 has a sound static type system, 
facilitated by a slightly different form of proceed than in AspectJ. 

This paper gives an operational semantics, type system, and proof of 
soundness for MiniMAO1.

Keywords: MiniMAO calculus, aspect-oriented programming, AspectJ, advice, 
          proceed, target 

2003 CR Categories: 
  D.3.1 [Programming Languages] Formal Definitions and Theory--Semantics 
  D.3.2 [Programming Languages] Language Classifications--object-oriented 
         languages 
  D.3.3 [Programming Languages] Language Constructs and Features--classes 
         and objects