> As seen at the top, it was necessary to annotate mod. It has the no-check flag on it, which is basically how you tell core.typed to just take your word on this one. That's something you can't do in Haskell, but I'm not sure whether or not that's a good thing.
Isn't the reason why you need to do it because you're importing a non-typed symbol? Wouldn't the only situation where you'd need to do that in Haskell be at FFI?
(and a nitpick: `putStrLn $ show` can be replaced with a simple `print` call)
I'll save the value judgement for another time, but I'd like to point out an important difference:
As the word "unsafe" implies, these Haskell primitives forego type safety in addition to type correctness. That means you can get segfaults and other undefined behavior at runtime. Such a type error on the JVM will simply produce an exception at runtime.
That's debatable, however Data.Dynamic is built on top of Data.Typeable, which provides a lower level runtime type safety facility. I think we can both agree Typable has lots of interesting uses.
Typeable is interesting in theory and generic traversals are a godsend, but usually I find that when I'm reaching for that particular hammer I should check twice.
The difference is that Haskell does not check types at runtime like Clojure does (which is the point of strong static typing), so if the type is wrong it becomes as unsafe as C.
Isn't the reason why you need to do it because you're importing a non-typed symbol? Wouldn't the only situation where you'd need to do that in Haskell be at FFI?
(and a nitpick: `putStrLn $ show` can be replaced with a simple `print` call)