Remote procedure calls are computationally expensive, because network round-trips take several orders of magnitude longer than local interactions. One common technique for amortizing this cost is to batch together multiple independent requests into one compound request. Batching requests amounts to serializing the abstract syntax tree of a small program, in order to transmit it and run it remotely. The standard representation for abstract syntax is to use free monads; we show that free applicative functors are actually a better choice of representation for this scenario.

I am Director of the Software Engineering Programme, which offers part-time professional Masters’ degrees in Software Engineering and in Software and Systems Security. I am currently the Chair of Faculty of Computer Science. For the academic years 2008-2010 was also Deputy Director of the Computing Laboratory (now the Department of Computer Science). I am a fellow of Kellogg College. Before taking up this post in 1999, I held lectureships at Oxford Brookes University and the University of Auckland, New Zealand.