Aspect-oriented Programming versus Reeection: a Rst Draft

Reeection has a long history of dealing about some aspects of software components. In this short position paper, we compare and contrast reeection and aspect-oriented programming. Whilst reeection has recently focused on very speciic aspects of software components, namely implemen-tational usually segregated among structural (representation) and behavioral (execution) aspects, aspect-oriented programming wishes to broaden the spectrum of attributes of software taken into account. On the other hand, weaving the aspects into a coherent and faithful implementation of their prescriptions is by nature a reeective process which can be put into the hand of aspect-oriented programmers using reeection. Finally, a link can be made between aspect-oriented programming and the underinvestigated area of declarative reeection. 1 Context During the last fteen years, we have been involved in research on reeection in programming languages. Our contributions encompass: 1. object-oriented metamodels Coi87], 2. semantics of behavioral reeection in the context of object-oriented languages MDC96], 3. programming methodologies for the composition of metacomponents MMC95], 4. use of explicit metaclasses to describe properties of classes LC96]. Our interest is in methodologies and techniques to enhance the adaptability and the composability of object-oriented software components. 2 Reeection Reeection in computer science in general has been rst suggested in the context of artiicial intelligence where the construction of self-aware systems can be assimilated to the end goal of the eld (see the two papers of Perlis Per85, Per88]). In the context of programming languages, the seminal work of Brian Smith Smi82, Smi84] has been the departure point of a large research eeort both in the functional and the object-oriented programming community. It is not our goal to introduce reeection here; the reader is refered to the paper of Malenfant and Demers for more details DM95]. A general deenition of reeection is due to Smith WRM90, discussion during the workshop]: \An entity's integral ability to represent, operate on, and otherwise deal with its self in the same way that it represents, operates on and deals with its primary subject matter." In the eld of programming languages, this deenition has been further reene to the following BGW93]: