A Compilation Model for Aspect-Oriented Polymorphically Typed Functional Languages

Introducing aspect orientation to a polymorphically typed functional language strengthens the importance of

type-scoped advices

; i.e., advices with their effects harnessed by type constraints. As types are typically treated as compile time entities, it is highly desirable to be able to perform

static weaving

to determine at compile time the

chaining

of type-scoped advices to their associated join points. In this paper, we describe a compilation model, as well as its implementation, that supports static type inference and static weaving of programs in an aspect-oriented polymorphically typed lazy functional language,

AspectFun

. We present a type-directed weaving scheme that coherently weaves type-scoped advices into the base program at compile time. We state the correctness of the static weaving with respect to the operational semantics of

AspectFun

. We also demonstrate how control-flow based pointcuts (such as

cflowbelow

) are compiled away, and highlight several type-directed optimization strategies that can improve the efficiency of woven code.