On Wed, Dec 11, 2013 at 5:17 PM, bearophile <bearophileh...@lycos.com>wrote:
> Namespace: > > Your gig: https://github.com/D-Programming-Language/dmd/pull/ >> 2952#discussion_r8288045 >> > > My enhancement request was for the array[$] syntax. The idea of []s was > invented by someone else (Timothee Cour?). > > I like the practical comments by Hara. If Kenji thinks the []s is not > useful for efficiency (because the efficiency can be obtained with just > improvements of the compiler), then the []s syntax becomes less necessary. > > > On the other hand this is an interesting use case that compiler > improvements alone could not be enough to allow: > > void fun(int[3]) {} > void main() { > int[3] x = [1, 2, 3]; > fun(x); // OK > fun([1, 2, 3]); // error > fun([1, 2, 3]s); // OK > } > yes, that was the prime motivation for DIP34, being able to pass un-ambiguously a static array to a function without having to declare an intermediate variable first. when fun() has overloads for both static and non-static arrays (or is just declared as fun(T)(T a) ), the compiler cannot guess whether fun([1,2,3]) asks for static or dynamic array, and probably has to assume dynamic array. And int[$] would require declaring a variable before passing it, eg: int[$]x=[1,2,3]. With [1,2,3]s, there is no ambiguity. > > > Are vector ops supported? > > int[6] a; > a = [1,2,3]s[] + [4,5,6]s[]; > > DIP34 is still a draft, and it shows, some corner cases are missing in > that document and need to be found, fleshed out and added to the DIP34. > > Bye, > bearophile >
