A typed monadic embedding of aspects

We describe a novel approach to embed pointcut/advice aspects in a typed functional programming language like Haskell. Aspects are first-class, can be deployed dynamically, and the pointcut language is extensible. Type soundness is guaranteed by exploiting the un-derlying type system, in particular phantom types and a new anti-unification type class. The use of monads brings type-based rea-soning about effects for the first time in the pointcut/advice setting, thereby practically combining Open Modules and EffectiveAdvice, and enables modular extensions of the aspect language. 1