I'm not talking about Haskell, i'm talking about Scala written in a functional style where we've used a lot of the concepts from Haskell. We're using it at Verizon for extremely large projects and it's working quite well. I know you've been pointed that out by others, so when you say there's no anecdotal data, how can you justify that?
I've talked to others who work at extremely large corporations finding success with it too in extremely large projects.
I am not looking for anecdotes that it is possible to write large programs in a pure functional style. I know it is possible. But, given the high cost of the approach (training, new libraries, maybe a new language and even a new platform) I am looking for anecdotes that the approach provides benefits that significantly outweigh its cost. I have not found any.
BTW, "extremely large projects" are anything above, say 20MLOC. What projects of that size have been written in pure functional style? What large projects (>5MLOC) have?
