A collection of DIPs

[Dmitry Olshansky via Digitalmars-d]

On 08-Sep-2015 19:09, Brian Rogoff wrote:
> On Tuesday, 8 September 2015 at 03:09:20 UTC, Rikki Cattermole wrote:
>> On 08/09/15 5:27 AM, Shammah Chancellor wrote:
>>> void main() {
>>>     import std.stdio : writeln;
>>>     writeln("Hello world!");
>>> }
>>>
>>> -Shammah
>>
>> It's not just an idiomatic way to code with local imports, it's a
>> compilation performance technique too.
>
> I didn't read the DIP collection thoroughly (yup, D has a some
> grotesqueries that would be nice to fix but I doubt will happen) but
> local imports are one of the nice features of D (and Ada, and OCaml)
> that I wish would be adopted in some other languages, like Nim and Julia.
>
> I never thought of them as a performance optimization though. What's the
> reasoning? Are the observed differences significant? From my POV
> restricting the scope of an import makes local reasoning easier. I'd do
> it even if it were slightly less performant!
>
>

Optimization comes when combined with templates - if template is not 
instantiated then the locals imports are not even read from disk.

-- 
Dmitry Olshansky