DIP61: Add namespaces to D

[Andrej Mitrovic via Digitalmars-d]

On 4/27/14, Walter Bright via Digitalmars-d <digitalmars-d at puremagic.com> wrote:
> When you find yourself doing things like that, seriously consider creating a
> new
> module to do it, called "clock".

That's not reliable, because static imports are not enforced. It means
anyone importing a module "clock" will automatically have all symbols
in "clock" imported into the current module, meaning this will work:

-----
import clock;

void main()
{
    auto time = currTime();  // note the lack of full qualification
}
-----

std.datetime rightly tries to discourage symbol pollution by default
(it has a lot of symbols to begin with). So you're forced to write:

-----
import std.datetime;

void main()
{
    auto time = Clock.currTime();
}
-----

> Using smaller modules under packages is a much better way.

Sorry, but this is currently impossible. Programmers will always use
the feature that actually works over a feature that might work some
day. Modules have too many open bugs right now, such as leaking
selective imports, private visibility, non-propagating package access,
etc etc.

If you ever try to build a larger library you'll immediately become
aware of these issues.