A fair amount. I used ML and Haskell in the 1990s in an academic setting, and have since used Haskell, Erlang, and Scala at various times while in industry. And I've tried out a number of other functional languages out of interest, as well.
Functional programming does offer some benefits, in some cases. I'm not suggesting that it doesn't. And while I don't think it'd be harmful to know Haskell, I'm not convinced that the benefit it would bring is necessarily worth the effort involved, especially for programmers who are already busy with work and other commitments.
Functional programming does offer some benefits, in some cases. I'm not suggesting that it doesn't. And while I don't think it'd be harmful to know Haskell, I'm not convinced that the benefit it would bring is necessarily worth the effort involved, especially for programmers who are already busy with work and other commitments.