In a Java context, I'd say it's undeniably true. Haskell-style composition of monadic values depends on type system features that Java doesn't have and on no ac

In a Java context, I'd say it's undeniably true. Haskell-style composition of monadic values depends on type system features that Java doesn't have and on no account should even be thinking about adding at this point in time. And that's ignoring the syntax mess it would be in Java today, too. In a Haskell context, since continuations are typically implemented as a monadic value, the statement would be more or less nonsensical. But I don't think that would be the context in question. Edit: noelwelsh speaks of another level of composition than I was, where one is trying to take, say, State and STM and create a new monadic value that does both those things. The analysis given there is correct as well. My point here is more syntactic and basic functioning, in that even if you pick a single monadic value type to stick with, it's not going to play well in Java anyhow. So, in conclusion, generalized monad-type code in Java is just comprehensively not really possible. Continuations, or what are being called that in modern times, however, fit into Java-type languages, as proved by several very similar languages that have had them for many years, and they work fine.