[cageface]

When SPJ is talking about concurrency, he is most likely talking about shared state with software transactional memory.

If you read the interview he is talking about the kind of implicit concurrency FP advocates often suggest you get for free with FP.

I suppose Haskell initially wasn't a concurrent language at all. It was a purely functional language and we had the idea from the beginning that a purely functional language was a good substrate for doing concurrency on. But it turned out to be a lot harder to turn that into reality than I think we really expected because we thought "If you got e1+e2 then you can evaluate e1 at the same time as e2 and everything will be wonderful because they can't affect each other because it's pure."

They had to add things like STM and explicit concurrency management because you don't get this for free just because you're doing FP.

[loup-vaillant]

Oh. He says "concurrent" to talk about data parallelism. (Bayesian update in progress…)