On Sat, 17 Oct 2009 22:47:21 +0200, grauzone <n...@example.net> wrote:
>Max Samukha wrote: >> On Sat, 17 Oct 2009 13:28:51 -0500, Andrei Alexandrescu >> <seewebsiteforem...@erdani.org> wrote: >> >>> Associative arrays are today quite problematic because they don't offer >>> any true iteration. Furthermore, the .keys and .values properties create >>> new arrays, which is wasteful. >>> >>> Another issue with associative arrays is that ++a[k] is hacked, which >>> reflects a grave language limitation. That needs to be replaced with a >>> true facility. >>> >>> Any other issues with AAs that you want to see fixed, and ideas guiding >>> a redesign? >>> >>> >>> Thanks, >>> >>> Andrei >> >> They should be true reference types. Now we have oddities like this: >> >> int[int] a; >> auto b = a; >> a[1] = 2; >> assert(b[1] == 2); // Range violation >> >> int[int] a; >> a[1] = 2; >> auto b = a; >> a[2] = 3; >> assert(b[2] == 3); // Ok > >That's because the actual AA is allocated on demand (when you add the >first element). The new array type T[new] is going to have the same >"problem". I agree. But the problem is the lack of a decent way to instantiate an empty AA. Now you either have to do idiotic things like: int[int] a; a[1] = 1; a.remove(1); Or wrap the array in another type. And, talking about T[new], we should be able to instantiate them eagerly as well. > >I like it, because if you don't need it, it doesn't allocate memory. Of >course it's possible that the complication in semantics isn't it worth. >But D is still a systems programming language with a *very* bad GC, >which is why I think it should continue to work this way.
