On Thursday, 7 August 2014 at 19:27:10 UTC, Ary Borenszweig wrote:
On 8/7/14, 3:57 PM, Andrei Alexandrescu wrote:
On 8/7/14, 10:35 AM, Puming wrote:
On Thursday, 7 August 2014 at 16:53:24 UTC, H. S. Teoh via
Digitalmars-d
It's really just the .init value of null which causes odd
behaviour with
empty AA's. Fun fact:
void changeAA(int[string] aa) {
aa["a"] = 123;
}
// Null AA:
int[string] aa1; // null
assert(aa1.length == 0);
changeAA(aa1); // no effect
for most of the new users the WAT part is actually here :-)
One function we could and should use is one that makes an AA
that is
empty but not null. Right now one needs to use goofy methods
such as
adding and then removing a key. -- Andrei
It still won't be intuitive for newcomers or for anyone not
knowing that function.
I would invert it: declaring an associative array makes it
non-null. Then you can choose, with a function, to initialize
to null.
This would follow the principle of least surprise.
It cannot be done, unfortunately. Think about struct members.
Their init value needs to be known at compile time, so the best
we could achieve would be to have all instances point to the same
AA by default, which is worse than what we have now.
