If you so choose to D can have a relatively clean library implementation. The type inference isn't bidirectional (Or at least it pales in comparison to HM) so it wouldn't be as good as ML-like FP.
Pattern matching is a feature of pure functional code rather than a requirement (As useful as it is, every time I touch haskell for fun I always miss the mathematical approach to coding when I then write in C-land).
Enforced purity is a feature, however. That's what I was referring to. However, ..., there is no pure-IO so it would be like Haskell before Monadic IO was figured out (I assume).
Pattern matching is a feature of pure functional code rather than a requirement (As useful as it is, every time I touch haskell for fun I always miss the mathematical approach to coding when I then write in C-land).
Enforced purity is a feature, however. That's what I was referring to. However, ..., there is no pure-IO so it would be like Haskell before Monadic IO was figured out (I assume).