Etienne Kneuss wrote:
Hello,
On Tue, Jan 12, 2010 at 11:40 PM, Chris Stockton
<chrisstockto...@gmail.com> wrote:
Hello,
On Mon, Jan 11, 2010 at 8:32 PM, mm w <0xcafef...@gmail.com> wrote:
cast is not needed in PHP
i 'd rather be more interesting in
class Obj {
function __catch($data, $type) {
//$type [ static_method, method, get_property, set_property]
if (observed && $type == set_property && somevalueIsObserved) {
$observer->notify("somevalue::valueWillChanged");
$this->somevalue = $data['somevalue'];
$observer->notify("somevalue::valueDidChanged");
} else {
continue__call();
}
}
}
What? ...
Etienne Kneuss wrote:
This is where operator over-loading would be useful however perhaps only
explicit casts would make sense here.
I beleive adding a __cast(string $type) would be a useful feature for
me, very often I have a toArray method defined. I agree with you that
due to unexpected edge cases with operator precedence and general type
juggling that __cast should only be called on explicit (cast).
I.E.:
class Int { public function __cast($type) { return 'int' == $type ? 15 : 0; } }
$r = new Int;
This is an exemple where __cast would be very wrong. At the very
least, it should return a value that is an inhabitant of the requested
type! Do you really want (bool)new Int() to be Int 0?
as a result, you have three solutions:
1) have the engine issue an error in case the return value is not compatible
2) provide a return value for every possible types requested
3) throw an exception in case the cast is not handled
In the end, it looks way more complicated/magic than _simply_ defining
a toArray method that is used whenever you need an object to be an
array. You need an explicit cast anyway, so it's (array)$obj vs
$obj->toArray().
One difference between these two possibilities is that consumers of an
array parameter could consume an object castable to an array whereas it
would need to have knowledge that ->toArray() exists in the second scenario.
var_dump($r + 1); // 2
var_dump((int) $r + 1); // 16
var_dump((bool) $r + 1); // 1
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