Maintainability of Functional Reactive Programs in a Telecom Server Software

Functional Reactive Programming (FRP) is claimed to be a good choice for event handling applications. Current object- oriented telecom applications are known to suffer from additional complexity due to event handling code. In this paper we study the maintainability of FRP programs in the tele- com domain compared to traditional object-oriented programming (OOP), with the motivation that higher maintainability increases the service quality and decreases the costs. Two implementations of the same procedure are created: one using Haskell and the reactive-banana FRP frame- work and one using C++ and the OOP paradigm. Four software experts each with over 20 years of experience and three development engineers working on a product subject to study were engaged in evaluations, based on a questionnaire involving five different aspects of maintainability. The evaluations indicate a higher maintainability profile for FRP compared with OOP. This is confirmed by a more detailed analysis of the code size. While performance was not a main criteria, a preliminary evaluation shows that the OOP prototype is 8-10 times faster than the FRP prototype in the current (non-optimised) implementations.Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or re-publish, to post on servers or to redistribute to lists, requires prior specific permissionand/or a fee. Request permissions from permissions@acm.org.