Accessors, byLine, input ranges

[Pelle Månsson]

On 01/29/2010 06:19 PM, Andrei Alexandrescu wrote:
> Ary Borenszweig wrote:
>> Andrei Alexandrescu wrote:
>>> Steven Schveighoffer wrote:
>>>> On Fri, 29 Jan 2010 11:21:28 -0500, Andrei Alexandrescu
>>>> <SeeWebsiteForEmail at erdani.org> wrote:
>>>>
>>>>> How is f.byLine clearer and less ambiguous than f.byLine()? Or vice
>>>>> versa for that matter?
>>>>
>>>> Note that properties can be named things other than byLine.
>>>>
>>>> -Steve
>>>
>>> What I meant to say is that in the @property landscape the following
>>> two conventions become suddenly attractive:
>>>
>>> * Do not use @property at all
>>>
>>> * Use @property for all nullary functions
>>>
>>> And they're bound to save a lot of time to everyone involved.
>>
>> The first post of this thread was about not invoking a function when
>> you don't want it to be invoked. bearophile was doing:
>>
>> auto dg = int function() { ... };
>> return dg;
>>
>> but he wanted to return a reference to dg, not the result of invoking
>> it. One way to prevent that is to never invoke functions unless they
>> are marked with @property. Or maybe functions defined like that
>> (closures, whatever) should always require () to be invoked.
>>
>> If that doesn't sound reasonable, see this:
>>
>> auto dg1 = int function() { ... };
>> auto dg2 = dg1;
>>
>> I'd expect dg2's type to be dg1's type.
>>
>> Let's just think a solution to this problem first. :-)
>
> Correct. Just that I fear that it's a bit late for this all. It is
> disheartening enough that Walter got convinced by the past discussion
> and introduced @property without much design - after a FAILED vote no
> less. I strongly believe a better solution is available, but everyone
> wanted the feature so the feature just got born.
>
> FWIW, my take for issues like the above: if a function returns a
> function or a delegate, it can't avail itself of automatic invocation of
> "()". That takes care of a corner case and keeps the mainstream case in
> good shape.
>
> I am not sure of a good solution for problems like
>
> writeln = 2;
>
>
> Andrei

How about @property? When you add a @property to a function it can be 
called as an assignment. @property does not touch the calling of 
no-argument functions.

Are there any problems with that?