OP mentioned "Ada's approach to types", as well. Ada lets you write stuff like "T is range 1 .. 20" or "T is range -1.0 .. 1.0 digits 18". This then gets mapped to the appropriate hardware integer or floating-point type.
Yeah, I've read little snippets like that from blog posts and stuff, but I've never written a single line of Ada, so I really don't know how that works out in practice.
What happens if you overflow at runtime? A crash, I assume/hope?
My point of view is that this is the opposite of what I'm talking about anyway. Java is a high level language where we are usually writing in Java because we're agreeing to give up a lot of raw performance (heap allocations, tons of pointer chasing) in order to have convenient models (objects) and not have to worry about memory management, etc.
In light of the above, I don't see why the default for Java is to have these really nitty-gritty numeric types. I don't want to guess how big a number can be before launching my cool new product. Just like I don't use raw arrays in Java and have to guess their max size- I just use List<> and it will grow forever.
> What happens if you overflow at runtime? A crash, I assume/hope?
In Ada, if range constraints are broken at runtime, a Constraint_Error is raised (or 'thrown', if you prefer). [0] (That's assuming of course that range checks haven't been disabled, which is an option that Ada compilers offer you.)
> I don't see why the default for Java is to have these really nitty-gritty numeric types
At the risk of retreading our earlier discussion:
I think the short answer is performance. Java has lofty goals of abstraction, yes, but it also aims to be pretty fast. If it didn't, its appeal would diminish considerably, so it's reasonable that they struck a balance like this. Same goes for why primitives aren't objects.
It depends on the base type - you can get the traditional unsigned integer wraparound behavior, too. But Ada is very explicit about this, to the point of referring to them as "modulo types", and defining them using the mod keyword instead of range:
Think of range of permissible values as a contract. I agree that the default should be "no limit", but there are many cases where you do, in fact, want to limit it, that have nothing to do with performance per se - but if the language has direct support for this, then it can also use the contract to determine the most optimal representation.
What happens if you overflow at runtime? A crash, I assume/hope?
My point of view is that this is the opposite of what I'm talking about anyway. Java is a high level language where we are usually writing in Java because we're agreeing to give up a lot of raw performance (heap allocations, tons of pointer chasing) in order to have convenient models (objects) and not have to worry about memory management, etc.
In light of the above, I don't see why the default for Java is to have these really nitty-gritty numeric types. I don't want to guess how big a number can be before launching my cool new product. Just like I don't use raw arrays in Java and have to guess their max size- I just use List<> and it will grow forever.