Reddit: why aren't people using D?

[Walter Bright]

Ary Borenszweig wrote:
> Walter Bright wrote:
>> Michiel Helvensteijn wrote:
>>> * No control over their use by class designer: ANY member function 
>>> with one
>>> or zero parameters may be called using 'property syntax'. This is not a
>>> good thing.
>>
>> Why not? Seriously, what is the semantic difference?
> 
> Semantic difference: a property doesn't have *visible* side effects. If 
> you invoke it one hundred times, it should always return the same thing. 
> And nothing else in your program should change. So it's kind of like 
> pure functions.
> 
> I say "visible" because you might want to implement a property lazily. 
> But the logic remains inside your class and it's visible in the outside 
> world.

Ok, but not having visible side effects is just a convention, one which 
is apparently not enforced by languages with special property syntax.

A pure function, however, can be statically guaranteed to have no side 
effects. So IDEs, etc., can regard as 'properties' any such methods 
which take no arguments.