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Date: Thu, 27 Oct 2005 18:55:05 -0400
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To: Jessie Hernandez <jrhernandez05@gmail.com>
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References: <435FCBC1.3030105@unFocus.com> <F6.28.22886.5BADF534@pb1.pair.com>
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Subject: Re: [PHP-DEV] Re: Namespace methods
From: CaptainN@unFocus.com (Kevin Newman)

Thank you for the info.

I have some questions/suggestions (they may be silly - please feel 
welcome to tell me so, if they are):

You have solved the problem (grievance number 5) of file based scoping, 
by introducing a function that can only be used within __autoload (the 
autoload_import_class function). Is that function meant to be called 
from within the class file? If so, I'd like to offer an alternative, 
that would allow usage even outside of the __autoload function.

Namespaces are generally implemented in file based languages (like c, 
c++, c# etc.), so there isn't an issue with clearing out imported 
namespaces when a file ends - but since (let me know if this is an 
incorrect assumption) PHP is an inline based interpreter - it would make 
sense to have a way to remove namespaces after they have been imported. 
So the first suggestion is to add an unimport (export?) function that 
would do just that - remove imported classes (or functions/vars, etc.) 
from the current (or global?) scope.

This functionality combined with the get_imported_namespaces function 
would allow users to emulate file based namespaces from within the 
__autoload function, while allowing them to use the standard import 
statement from within class files. Here is a crude sudo code (that 
incorrectly assumes import and unimport take a string as an argument) 
example of an __autoload function that does that:

function __autoload($classname) {
    // class name figuring out code goes here
    ...
    // store current namespaces
    $current_namespaces = get_imported_namespaces();
    // remove all current namespaces
    foreach ($current_namespaces as $namespace_name) {
       unimport($namespace_name);
    }
    // include the class file
    require_once(...$classname);
    // remove all namespaces imported from the class file
    $new_namespaces = get_imported_namespaces();
    foreach ($new_namespaces) {
       unimport($namespace_name);
    }
    // reimport the $current_namespaces from the array
    foreach ($current_namespaces as $namespace_name) {
       import($namespace_name);
    }
}


The addition of two new functions - clear_all_namespaces() and 
import_namespaces() (or reimport_namespaces, restore_namespaces, etc.) 
could help clean that up a bit. The example would then look like this:

function __autoload($classname) {
    // class name figuring out code goes here
    ...
    // store current namespaces
    $current_namespaces = get_imported_namespaces();
    // remove all current namespaces
    clear_all_namespaces();
    // include the class file
    require_once(...$classname);
    // remove all namespaces imported from the class file
    clear_all_namespaces();
    // reimport $current_namespaces from the array
    restore_namespaces($current_namespaces);
}

You can see from the example, how this would work inline, just as well 
as within the __autoload function.

Am I completely nuts here? What do you think?

Kevin N.

PS You could even wrap all those Namespace manipulation methods into a 
class (initial attempt):

<?php
interface Namespaces {
    /**
     * Alternative to the import statement.
     * @param $ns_name - a string containing the name of the namespace 
to import
     */
    public static import($ns_name);
   
    /**
     * Removes an imported namespace.
     * $param $ns_name - a string containing the name of the namespace 
to unimport
     */
    public static unimport($ns_name);
   
    /**
     * Clears all imported namespaces.
     */
    public static unimport_all();
   
    /**
     * Clears a collection of namespaces.
     * $param $ns_names - an array containing the names of the 
namespaces to clear
     */
    public static unimport_multiple($ns_names);
   
    /**
     * Imports a collection of namespaces (can be used to restore a 
previously cleared collection).
     * $param $ns_names - an array containing the names of the 
namespaces to clear
     */
    public static import_multiple($ns_names);
   
    /**
     * Get a list of current imported namespaces
     * @return array of currently imported namespaces
     */
    public static get_imported();
}
?>



Jessie Hernandez wrote:
> Kevin,
>
> Just to make sure, you can get the latest patch from
> http://www.zend.com/zend/week/pat/pat44.txt. For documentation, please
> refer to this post: http://news.php.net/php.internals/17484.
>
> Let me know if you have any questions or if you still cannot get the patch
> to compile (I wrote the patch against a 5.1 CVS version some months ago,
> maybe it doesn't apply cleanly anymore, haven't tried).
>
>
> Regards,
>
> Jessie Hernandez
>
>
> Kevin Newman wrote:
>
>   
>> Hello,
>>
>> I have been trying to compile PHP with the namespaces patch, but have
>> been completely unable to find the time after an initial attempt failed
>> (I'm compiling on windows). So I just wanted to know what methods this
>> patch provides, if it does at all. Does it support import for example?
>> If so, is there any documentation on the methods the patch provides?
>>
>> Thanks,
>>
>> Kevin N.
>>     
>
>