On 01/03/2017 20:46, Pedro Magalhães wrote:
As a clarification, the current implementation of the PR affects arrays in
general, not only array_fill. Any array that starts with a negative index
would continue from that index instead of 0. Meaning that [-2 => true,
true, true] would now return [-2 => true, -1 => true, 0 => true] instead of
[-2 => true, 0 => true, 1 => true].
Hi Pedro,
Would other behaviour also be affected?
For instance:
$foo = [ -2 => true ];
$foo[] = true;
$foo[] = true;
var_dump($foo);
If so, this is a much wider BC break; if not, why not?
Currently, this is completely consistent: https://3v4l.org/hXAsf Indeed,
I would say this is the missing explanation of why array_fill works the
way it does.
Presumably, this is why there is a note on the manual page:
See also theArrays <http://php.net/manual/en/language.types.array.php> section of
manual for a detailed explanation of negative keys.
Although as pointed out by Andrew Nester, this "detailed explanation"
doesn't actually seem to exist. This seems to be the closest we get:
As mentioned above, if no key is specified, the maximum of the existing integer indices is taken, and the new key will be that
maximum value plus 1 (but at least 0). If no integer indices exist yet,
the key will be 0 (zero).
Hidden in that first rambling sentence is the key phrase "but at least
0"; and the second should really say "If no positive integer indices..."
[It shouldn't say "exist", either, because as the next paragraph
explains, it can actually be affected by keys that no longer exist;
which I'd never actually realised before!]
This deserves to be a full section rather than a note, and much more
clearly articulated. It might even make sense to split that page into
sub-pages in some way, but I'm drifting into a different discussion, for
a different list.
The point right now is that array_fill's behaviour is actually
consistent with the rest of the language, and while the value of that
behaviour is questionable, changing it now would be a major decision.
Regards,
--
Rowan Collins
[IMSoP]
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