Hello Gregory,
Tuesday, November 4, 2008, 5:15:35 PM, you wrote:
> Christian Schneider wrote:
>> Lukas Kahwe Smith wrote:
>>> one could also do
>>> 1) ns
>>> 2) global
>>> 3) autoload
>>
>> I'm in favour of this (if it avoids performance problems) as I don't see
>> a problem with giving global priority over autoload.
> Hi,
> This is the current name resolution. The problem is that:
> <?php
> namespace foo;
> $a = new Exception();
?>>
> will instantiate foo::Exception only if the class already exists, but
> will instantiate Exception otherwise. This defeats autoload's purpose
> for existing. We've been over this before. It's dangerous.
> There is one essential difference between classes and
> functions/constants: autoload.
> The only time the question of load order and fallback becomes and issue
> is when code is not explicitly loaded. In other words, a developer who
> is relying upon an external function will do this at some point before
> calling the function:
> <?php
> include 'path/to/code/containing/function/source.php';
?>>
> In other words, PHP expects you to actually load the source of functions
> or constants you're going to be using in advance of using it.
> This, I believe, is a reasonable expectation.
> Classes, however, do *not* share this same expectation, because
> autoload's explicit purpose is to allow using classes *before* their
> source has been loaded.
> In other words, it is perfectly all right to have a different name
> resolution for classes than we have for functions and constants because
> of this different expectation. It is dangerous to fallback for classes
> prior to autoload, but it is not at all dangerous for
> functions/constants because the expectation is different.
> For this reason, the only resolution that we should be considering is:
> classes:
> 1) try ns::class
> 2) autoload ns::class
> 3) fail
Since we can stack autoload we could provide a c-level autoload function
that does the default lookup.
function global_autoload($name) {
if (($p = strrpos($name, '\\')) !== false) {
$name = substr($name, $p);
if (__NAMESPACE__ == substr($name, 0, $p -1) && class_exists("\\$name")) {
use "\\$name"; // if we find a way to do this at C-levle
}
}
}
> functions/constants:
> 1) try ns::function/ns::const
> 2) try internal function/const
> 3) fail.
> Note that I say "try internal" because the only purpose behind allowing
> this is to make it easier to use PHP's built-in functionality. Any
> userspace stuff should be specifically \prefixed or imported via use.
> And (yes) we need import for functions.
> Greg
> P.S. my mail server has been down for almost a week, apologies to anyone
> who is wondering why I haven't replied to your message, I probably
> didn't get it.
Best regards,
Marcus
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