3 ms·

I think you're talking past the comment you're replying to. In both examples, you have tell the compiler exactly what the types are. In the first one you have

by moefh 4y ago

I think you're talking past the comment you're replying to. In both examples, you have tell the compiler exactly what the types are. In the first one you have to cast the return value of `dlsym` to a function pointer, and at that point, as far as the compiler is concerned, it's a function. In the second example you have to explicitly declare the struct containing function pointers, so of course you can call its members. So it's strange to suggest that C is somewhat untyped; it's not untyped at all. C just makes it very easy to force the compiler to assume different type for a value (that's necessary for low-level code like the examples in the comment you replied to; and of course that makes it very easy to do unsafe things, I don't think anyone disputes that). And about the "weak typing system" comment, note that nobody agrees on what exactly that means. Just as an example, see how this page[1] defines "weaker" vs "stronger" types, and how it's completely different from the way you're using here. In general, I find people call type systems that don't do what they expect or want "weak", but that's not an useful discriminator: at that point you might just call it "bad typing" to dispel any illusion that it has any objective meaning. [1] http://book.realworldhaskell.org/read/types-and-functions.html http://book.realworldhaskell.org/read/types-and-functions.ht...

woodruffw 4y ago
I didn't say it was "somewhat untyped." I said it has a very weak static typing system. Just because "weak typing" means something different in Haskell doesn't mean it can't be used meaningfully (and beyond "bad") in the context of C. C's typing is historically referred to as "weak" because C's notion of casting doesn't distinguish between type and value transmutation: pointer-to-pointer casts don't convert the referent (because they can't), which in turn gives the C compiler very little leeway in proving that the program's types as declared have any particular meaning at runtime. Compare this to Python, which is "strongly" typed in the same sense: doing `y = str(x)` on `x` means that `type(y)` actually is `str`, and not merely a promise to the runtime. It's enforced, which makes it strong.
- moefh 4y ago
  My point about "weak typing" is this: if someone says "hey, I'm designing a new language, its type system is going to be weak", they gave you no information whatsoever about the type system other than maybe "some people on the Internet will probably complain about it". That's why it's useless to say things like "it's about as weak as a static typing system can be" and "has been historically considered weak". If you had explained your objection to C's type system (like you have now), I wouldn't have said anything. And I've been on the Internet long enough to have seen C's typing is historically referred to as "weak" because X for *many* values of X, so I disagree that that's the only or even main objection.

by moefh 4y ago

woodruffw 4y ago

I didn't say it was "somewhat untyped." I said it has a very weak static typing system. Just because "weak typing" means something different in Haskell doesn't mean it can't be used meaningfully (and beyond "bad") in the context of C. C's typing is historically referred to as "weak" because C's notion of casting doesn't distinguish between type and value transmutation: pointer-to-pointer casts don't convert the referent (because they can't), which in turn gives the C compiler very little leeway in proving that the program's types as declared have any particular meaning at runtime. Compare this to Python, which is "strongly" typed in the same sense: doing `y = str(x)` on `x` means that `type(y)` actually is `str`, and not merely a promise to the runtime. It's enforced, which makes it strong.

moefh 4y ago
My point about "weak typing" is this: if someone says "hey, I'm designing a new language, its type system is going to be weak", they gave you no information whatsoever about the type system other than maybe "some people on the Internet will probably complain about it". That's why it's useless to say things like "it's about as weak as a static typing system can be" and "has been historically considered weak". If you had explained your objection to C's type system (like you have now), I wouldn't have said anything. And I've been on the Internet long enough to have seen C's typing is historically referred to as "weak" because X for *many* values of X, so I disagree that that's the only or even main objection.