Simen kjaeraas:
I think you have missed one important point: that was not my list of things I'd
like in D2/D3. It contains some cute things, but it's first of all a summary of
the linked stackoverflow thread. My personal list of desiderata for D3 is
different.
> Absolutely. While it's possible today, some more sugar wouldn't hurt.
I think Walter said this can't be implemented :)
The items alignment of function arguments used by D tuples is not fitting to
return a struct. I have not understood the details of this thing, and in the
end I don't care if returning a struct can decrease performance a bit...
> > in for arrays:
>
> Yes.
I think Walter doesn't like this because he thinks "in" has to always look for
keys, and keys of an array are its indexes. I don't agree with Walter here, but
I don't think he will change his mind soon.
> Neat. Worthy an @keyword, I think. "@flag enum foo {...}"
It's cute. But Don hates attributes :-) Recently I have created a thread about
this, and some one has written a good enough implementation in normal D code,
that can be "good enough".
> I feel this is a tad too sweet. On the one hand I like it, on the
> other I feel it will lead to bugs at a later point, by hiding null
> pointers and not teaching programmers to deal with them.
> "Add a ? to all object accesses. It is magical and removes bugs."
I agree. It can be handy but it can lead to bugs too, so I don't know what to
think about it.
> Given an event system, what are the advantages to language
> support for this?
I don't know.
> > Exception grouping to avoid duplicating the same handling logic
>
> Very nice.
I have proposed something similar time ago. Python uses a tuple of possible
exceptions, I was not expecting D to allow only one of them. Some form of this
can be added to D2.
> > @memoize
> >
> > Or something similar user-defined. It is really useful, to avoid coding
> > true dynamic programming algorithms.
>
> This again is to sweet for me. What does @memoize do? Does it
> store the last 5 results? All results? The last result only?
> Does it depend on the phase of the moon, time of day and what
> socks I'm wearing?
That's why I have said user-defined (in Python too it's user defined), so you
can define and use the one you prefer. But currently D properties are not
flexible enough to allow programmers to define them.
> So "a as b" rather than "cast(b)(a)" or "to!(b)(a)"? Or is there
> some other magic at work that I don't see?
I think there is no magic, it's just syntax sugar.
Bye,
bearophile
