@property - take it behind the woodshed and shoot it?

[Andrei Alexandrescu]

On 1/24/13 8:01 PM, Timon Gehr wrote:
> On 01/25/2013 12:23 AM, Adam Wilson wrote:
>> ...
>>
>> But what happens if t.baz returns a delegate?
>>
>
> You mean, a parameterless delegate. How many times does this occur that
> it supports nuking a entire language feature?
>
>> Because properties, which conceptually have nothing to do with
>> functions, are implemented as functions they have the same optional
>> parens rules as functions.
>
> Because the compiler is broken.
>
>> The problem is that they aren't intended to
>> be used as functions so in the case of delegate, you get massive
>> explosions in the compiler. For something that should be
>> straight-forward. If t.baz is a delegate than t.baz() should call the
>> DELEGATE, but it doesn't...
>>
>
> It should for @properties.
>
>> Optional Parens Encourage Ambiguity.
>
> We could talk about fixing that particular situation, eg, only allow
> paren-free calls when no parameterless callable is returned, with a very
> explicit error message. (Like Jesse suggests as well.)
>
> However, note that scala does the same we do now:
> scala> def foo()=()=>2
> foo: ()() => Int
>
> scala> foo
> res1: () => Int = <function0>
>
> scala> foo()
> res2: () => Int = <function0>
>
> scala> foo()()
> res3: Int = 2
>
> I do not think this is a recurring discussion topic on the scala
> newsgroup. I think we might actually be fine.
>
>> Ambiguity Fosters Bugs.
>>
>
> Delegates not being called is noticed quickly.

I feel we're getting somewhere!

Andrei