Uniform Function Call syntax for properties

[Robert Jacques]

On Sat, 09 Oct 2010 22:03:56 -0400, Denis Koroskin <2korden at gmail.com>  
wrote:

> On Sun, 10 Oct 2010 05:58:00 +0400, Robert Jacques <sandford at jhu.edu>  
> wrote:
>
>> On Sat, 09 Oct 2010 16:28:32 -0400, Denis Koroskin <2korden at gmail.com>  
>> wrote:
>>
>>> On Sun, 10 Oct 2010 00:09:23 +0400, Sean Kelly  
>>> <sean at invisibleduck.org> wrote:
>>>
>>>> Andrei Alexandrescu <SeeWebsiteForEmail at erdani.org> wrote:
>>>>> On 10/8/10 7:55 CDT, Steven Schveighoffer wrote:
>>>>>> Someone was asking about UFC syntax for properties on d.learn, and I
>>>>>> realized, we have a huge ambiguity here.
>>>>>>
>>>>>> Given a function:
>>>>>>
>>>>>> @property int foo(int x)
>>>>>>
>>>>>> Is this a global setter or a getter on an int?
>>>>>
>>>>> Good question.
>>>>
>>>> Setter. Consider "a = b = c".
>>>
>>> I think you missed the point. Which of the two is it:
>>>
>>> int x = 42;
>>> auto y = x.foo(); // transformed into "auto y = foo(x);", getter
>>>
>>> or
>>>
>>> foo = 42; // transformed into "foo(42);", setter
>>>
>>> Both match.
>>
>> I agree that there is ambiguity here, but does it why does foo have to  
>> be only a getter or only a setter? Why can't it behave like either,  
>> depending on its implementation and use?
>
> Because you may want to have both, but you can't because their syntax  
> overlap.

Okay I'm confused. How do their syntax overlap? And which syntaxes do you  
think are overlapping?
All the following 'lowerings' look fine/unambiguous to me:

foo = 42; => foo(42);
y = x.foo; => y = x.foo(); => y = foo(x);
foo = foo = x.foo; => foo = foo = x.foo(); => foo = foo = foo(x); => foo =  
foo(foo(x)); => foo(foo(foo(x)));