Why I'm Excited about D

[deadalnix via Digitalmars-d]

On Monday, 13 April 2015 at 05:46:32 UTC, Dicebot wrote:
> On Sunday, 12 April 2015 at 18:42:01 UTC, Andrei Alexandrescu 
> wrote:
>> On 4/12/15 10:43 AM, Dicebot wrote:
>>> It is much better in languages that do support dedicated 
>>> properties
>>> because language rules can be used to express the same notion 
>>> without
>>> resorting to any conventions.
>>
>> Wouldn't e.g. C# allow arbitrary code in getters and setters? 
>> And if so, wouldn't C# code need to resort to conventions to 
>> avoid surprising behavior? -- Andrei
>
> This is totally reasonable way to put it but in practice there 
> are enough differences to keep it maintainable. With dedicated 
> getters decision (and reviewer attention) is focused on 
> definition of getter and done there once and for all. Some 
> tough decisions are inevitable but it is at least possible to 
> ensure that all such decisions are deliberate. In D such 
> decision is done at call site which makes it very hard to 
> review as changes are distributed everywhere. Though DScanner 
> can possibly help here and I am really looking forward trying 
> to it in our code control.
>
> That said, I think the main reason why this notion didn't work 
> well for D when @property was introduces is because of 
> extremely vague range semantics. I find it important that you 
> have mentioned exactly `front` and `popFront` as examples for 
> unclear parens placement - problem with those is that there 
> isn't. `front` may or may not be trivial getter depending on 
> (sometimes arbitrary) decision by range implementor, there is 
> no uniformity between those. Which makes impossible to enforce 
> consistent calling style and makes "drop everything" approach 
> much more tempting.

Very good point. I've been bitten by range semantic many times, 
especially map, which is lazy and does the work on front call, 
rather than popFront as I would have expected.

Thinking about it, this is probably the right thing to do, but 
the range interface makes it non obvious and confusing.