Dear Internals
I'm very happy that this is getting some attention again. Please allow
me to give my 2 cents too. The text below can also be seen nicely
formatted at https://gist.github.com/909711.
## Intro ##
Isset and IsNotEmpty operators have for sure been a hot topic for several years
now and in my opinion rightly so. The non-DRY style of:
$my_array['my_long_boring_key'] = !empty($my_array['my_long_boring_key'])
? $my_array['my_long_boring_key'] : 'Default value';
$my_array['my_long_boring_key'] = isset($my_array['my_long_boring_key'])
? $my_array['my_long_boring_key'] : 'Default value';
is a true day-to-day hassle and addressing this annoyance would be a
big win for
the PHP community as a whole. As PHP has two keywords `isset` and `empty` that
can check for a non existing variable without throwing errors I think there
should exist two assignment/ternary operators who mirror those.
I have been thinking [1] about the same problem for my meta language Snow and
also ended up using `??` as an isset operator.
## Proposal ##
I propose that two new operators `??` (IssetOperator) and `?!`
(NotEmptyOperator) are added. `??` mirrors `isset` and `?!` mirrors `!empty`.
They are chainable ad nauseum but not with each other.
They would work like this:
### Example 1 : Ternary shortcut ###
Old syntax:
$a = isset($b) ? $b : 42;
$a = !empty($b) ? $b : 42;
New syntax:
$a = $b ?? 42;
$a = $b ?! 42;
### Example 2 : Direct assignment ###
Old syntax:
$arr['key'] = isset($arr['key']) ? $arr['key'] : 42;
$arr['key'] = !empty($arr['key']) ? $arr['key'] : 42;
New syntax:
$arr['key'] ??= 42;
$arr['key'] ?!= 42;
### Example 3 : Works with statements too ###
Old syntax:
// a)
$tmp = get_stuff('foo');
$a = isset($tmp) ? $tmp : 42;
// b)
$tmp = get_stuff('foo');
$a = !empty($tmp) ? $tmp : 42;
New syntax:
// a)
$a = get_stuff('foo') ?? 42;
// b)
$a = get_stuff('foo') ?! 42;
### Example 4 : Chaining ###
Old syntax [2]:
$a = false;
if (!empty($c) {
$a = $c;
} else {
$tmp = get_stuff();
$a = !empty($tmp) ? $tmp : false;
}
if ($a === false) {
$a = !empty($c) ? $c : 42;
}
New syntax:
$a = $c ?! get_stuff() ?! $b ?! 42;
### Example 5 : Illegal syntax ###
$a = $d ?? $c ?! $b ?? 42; // `??` and `?!` cannot be mixed.
## References ##
* [1]: http://code.google.com/p/php-snow/wiki/EmptyIssetOperators
* [2]: This could also be done by nesting ternary operators, but that gets
even more unreadable I think.
--
PHP Internals - PHP Runtime Development Mailing List
To unsubscribe, visit: http://www.php.net/unsub.php
