[Haskell-cafe] special term describing f :: (Monad m) => (a -> m b ) ?

[Ralf Hinze]

> I can understand how calling this kind of function "effectual" makes 
> sense in the "magic" IO monad, or perhaps even in the ST and State 
> monads, because the term seems to imply side-effects.  However, it is a 
> misnomer for eg, the Error, List and Cont monads.

It depends a bit on how wide you interpret the term "effectfull".
For me, exceptions or partiality (Error), non-determinisms or
backtracking (List) and continuations (Cont) are certainly effects.

Cheers, Ralf