[layer8]

> see what kind of trouble Java gives you, for example.

I program a lot in Java, and the only trouble there is the lack of support for sum types and/or variadic type parameters in generics (i.e. to express functional interfaces that can throw an arbitrary number of checked exceptions, as a type parameter). That’s the only pain point for me and is something that could be fixed.

In fact, the interplay with control structures is exactly what I was referring to by syntactic sugar. Indeed it also concerns the type system.

But let’s talk about that, not about exceptions good/bad or error values good/bad. That’s too simplisitic.

[Fellshard]

I mean, syntactic sugar is one thing, but being entirely incapable of creating variadic exceptions really hamstrings you in places where you don't wish to write a great deal of redundant code for each combination of exceptions you may see.

[layer8]

Completely agreed about variadic exceptions, but that's not a drawback of exceptions, it's a limitation of Java's supported syntax for generics. In catch clauses, Java already has exception sum types (`catch (FooException | BarException ex)`), and Java also has variadic method parameters, so why not have variadic type parameters, maybe something like `Foo<V extends Bar, T... extends Throwable>` that can be instantiated as `Foo<SomeBar, BazException | QuxException>`.

[Fellshard]

Yep! I'd love to see something like this in Java, but it's unlikely, probably for the usual runtime type erasure reasons. Exceptions can be implemented in this way, and would strike a nice balance in doing so.