[marcosdumay]

It's possible that what makes functional languages easier to reason about and debug is the fact that they allow the types to capture a lot more information than the imperative languages.

What would also explain why Prolog has none of those benefits. If you don't use the extra information, it can't do any good.

But if it is really just that, it can be replicated over imperative languages. Anyway, Rust is evidence that there is something to that idea.

[gr4vityWall]

Not disagreeing with you, though I'd say Rust syntax also feels very hard to understand most of the time. I think function signatures is something that I distinctly remember getting very complicated sometimes.

Which is unfortunate, as I like the principles behind it. I wonder if someone will ever write a Rust-like language that has a syntax closer to Java or Haxe.

[marcosdumay]

Oh, Rust type signatures are harder to use than even Haskell.

But that's because there are a lot of low level detail that must go into them. Most of the complexity that C developers tend to ignore (and create wrong programs) goes there, explicitly. If you don't want the detail, you can make them simpler.

That said, I have a long rant about how Haskell-like types ignore the entire "algebra" thing from algebraic types, and could be way more expressive and simpler to use.