Experience report: Haskell in the 'real world': writing a commercial application in a lazy functional lanuage

Abstract

I describe the initial attempt of experienced business software developers with minimal functional programming background to write a non-trivial, business-critical application entirely in Haskell. Some parts of the application domain are well suited to a mathematically-oriented language; others are more typically done in languages such as C++. I discuss the advantages and difficulties of Haskell in these circumstances, with a particular focus on issues that commercial developers find important but that may receive less attention from the academic community. I conclude that, while academic implementations of "advanced" programming languages arguably may lag somewhat behind implementations of commercial languages in certain ways important to businesses, this appears relatively easy to fix, and that the other advantages that they offer make them a good, albeit long-term, investment for companies where effective IT implementation can offer a crucial advantage to success.