Plot2kill 0.2

[Nick Sabalausky]

"Michel Fortin" <michel.fortin at michelf.com> wrote in message 
news:ikum9a$2agj$1 at digitalmars.com...
> On 2011-03-05 18:42:26 -0500, dsimcha <dsimcha at yahoo.com> said:
>
>> This is an extreme corner case, especially if a one-way semantic 
>> @property syntax is available to work around it.  The percentage of 
>> functions that return callables is very small, and of these the 
>> percentage that would forget @property is probably very small.  I'd 
>> rather bug-proneness in a ridiculous corner case than breaking tons of 
>> existing code code and losing a nice feature in the common case.
>
> The percentage of functions that return a callable is very small until you 
> go to template land. I can easily make a container or a range of 
> delegates, and if someone somewhere forgot to make 'front' a property in 
> the container, in the container's range or in one of the filter range 
> layered on top of it, then writing 'front()' to call the front delegate 
> becomes unreliable. Is it a corner case? Yes. Is it ridiculous to expect 
> the language to detect rare but hard to find bugs? No. Is it worth it in 
> this case? I think so.
>

Along those lines, I'll point out that the idea of a range of delegates is 
not a stretch at all: it could make a lot of sense for a GUI API, for 
instance. The .NET windowing API handles callbacks as collections of 
delegates and I always thought that worked fairly well (and seems 
functionally equivalent to Qt's system of signals and slots, AIUI).