[ericmj]

Purity has nothing to do with green threads. Many languages that doesn't have the concept of purity have green threads, like Erlang or Go. In fact, green threads are not a part of Haskell, but a part of the runtime. Purity is just a nice thing to have when working with threading or concurrent programs.

[ibotty]

well. but a no-shared-writeable-data approach (as with erlang) certainly helps. and that comes for free with purity.

i don't know how go handles that though. i'd be surprised if this was as efficient as in erlang and haskell.