[aiono]

Void in Haskell is not the same thing as `void` in C, C++, Java or similar languages. If you return `Void` in Haskell, you will get a runtime error but `void` returning functions in C-like languages don't fail. It's not a type that doesn't have any value, rather it's a type that has a single value (normal return). Therefore it's more similar to `unit`.

[chuckadams]

Void having no values means it's impossible to return it or call a function that accepts it, so that would make it a compile-time error as opposed to runtime, no?

[aiono]

In practice yes, so when you try to execute the function that accepts `Void`, that will error out. But there is no reason to not compile it because it will never actually execute. This may sound unpractical but quite the contrary it's very useful. For instance, it's used to model functions that panics in Rust (https://doc.rust-lang.org/reference/types/never.html). That way you can have a function called `todo` which fails when executed, but keeps the type checker happy until you actually implement it.