Type-Directed Weaving of Aspects for Polymorphically Typed Functional Languages

Incorporating aspect-oriented paradigm to a polymorphically typed functional

language enables the declaration of type-scoped advice, in which the

effect of an aspect can be harnessed by introducing possibly polymorphic

type constraints to the aspect. The amalgamation of aspect orientation and

functional programming enables quick behavioral adaption of functions, clear

separation of concerns and expressive type-directed programming. However,

proper static weaving of aspects in polymorphic languages with a type-erasure

semantics remains a challenge. In this paper, we describe a type-directed

static weaving strategy, as well as its implementation, that supports

static type inference and static weaving of programs written in an aspect-oriented

polymorphically typed functional language, AspectFun. We show

examples of type-scoped advice, identify the challenges faced with compile-time

weaving in the presence of type-scoped advice, and demonstrate how

various advanced aspect features can be handled by our techniques. Lastly,

we prove the correctness of the static weaving strategy with respect to the

operational semantics of AspectFun.