> That the author complains about having types rather than a simple map for keys shows a misunderstanding of what they are there for - the idea is to allow the

> That the author complains about having types rather than a simple map for keys shows a misunderstanding of what they are there for - the idea is to allow the compiler to prove at run-time what is valid code and what isn't. There's some evidence from what the author wrote he's aware of the benefits of type systems. The question he raises is whether the developers who wrote Spray modeled the problem domain well by choosing this particular set of types (his opinion is clearly no). > the author makes a strange comment that H-M 'enabled' Monads, and the comment is written in a way that implies that Scala does not have Monads. Given that the author immediately follows his "enabled" statement with the idea that monads can be used in a type-free language, I think it's most likely he means that H-M has been the ground where the use of monads has been largely developed/defined, not that monads can't be used in either Scala or even something with a considerably less expressive type system.