The Sweet With

[Jarrett Billingsley]

On Tue, Mar 3, 2009 at 3:32 PM, Nick Sabalausky <a at a.a> wrote:
>> "Jarrett Billingsley" <jarrett.billingsley at gmail.com> wrote in message
>> news:mailman.901.1236111433.22690.digitalmars-d at puremagic.com...
>> On Tue, Mar 3, 2009 at 1:50 PM, Walter Bright
>> <newshound1 at digitalmars.com> wrote:
>> > Tomasz Sowi&#324;ski wrote:
>> >>
>> >> Ideas for features based on the with.
>> >>
>> >> The with can make calling functions with enum arguments sexier. So
>> >> instead
>> >> of:
>> >> auto d = dirEntries(".", SpanMode.breadth);
>> >>
>> >> you could say:
>> >> auto d = dirEntries(".", breadth);
>> >>
>> >> by declaring the function as:
>> >> dirEntries(string path, with SpanMode mode); // "with" does the trick
>> >
>> > It looks nice, but has a subtle and disastrous problem. In D, arguments
>> > are
>> > fully resolved *before* overloading is done. If some of the overloads
>> > have
>> > with declarations, then there's a nightmarish problem of trying to mix
>> > overloading and argument resolution together.
>>
>> What about the feature you mentioned at the D con, about being able to
>> use enums without the enum name?  Or will/would that only be for
>> things where it's really obvious, like switch statements?
>
> Unless that was only for things like switch statements, I would hate that.
> I've used enums in languages that worked that way, and I found it to be such
> a problematic namespace-clutterer that in those languages I always hack up
> my enum definitions like this:
>
> enum Color
> {
>    Color_Red,
>    Color_Blue,
>    Color_Orange,
>    // etc...
> }
>
> Which is a style that I've always considered an ugly and kludgey, but
> unfortunately necessary, substitute for manditory enum names.

Oh, the way he described it in the slides was different.  As in,
normally you would use Color.Red, but inside a switch:

switch(widgetColor)
{
    case Red: // this is *completely* unambiguous
}

And such.  Red is not a global; it's rather that name lookup is
changed for some constructs.