Why not do somthing sensible like call a function that creates an array of callback references:

so 

function blah() {
$foo = array();
$foo["render"] = "bar";
}

$foo["render"]() would call bar();

There is no mention of function namespaces in PHP's documentation at all and we have never really seen the need for them. Changing to a feature/change request.

- James

My point here is that a function's name called within a function should remain entirely within that scope.  The concept is similarly supported here the documentation for the include() function:

"When a file is include()ed, the code it contains inherits the variable scope of the line on which the include() occurs. Any variables available at that line in the calling file will be available within the called file. If the include() occurs inside a function within the calling file, then all of the code contained in the called file will behave as though it had been defined inside that function." (http://www.php.net/manual/en/function.include.php)

I realize this is mostly in reference to variables and not directly about functions, but shouldn't the same rule hold true for both?  Functions within a class do not cause this problem.  They remain within scope of the class.  I can have functions of the same name in different classes, or as a result of multiple instances of the same class.  Shouldn't functions within another function do the same?

Maybe my example wasn't clear.  Our three goals:

1) Include files that are self-contained "snippets" of php and html.  The are displayed as blocks or elements of a web page.  Ie. navigation, headers, footers, picture w/ caption, list of events?.
2) The included files (design elements) can be programmed with limited experience and minimum complexity for more compact, easier, and faster coding.  Typically limited to simple functions, basic control structures, and database selects via an API.  Functions specific to the creation of the page's design and layout are coded in this include file.  Core functions (no design output) are already included and globally available.
3) The include file may be included one or more times on a page.

For instance, if you where to have a web page with a cookie-crumb navigation bar at the top and at the bottom, any functions that were part of the include file and helped to drill down the category structure would cause an error the second time the navigation file was included.  This is despite the fact that in each case when the file was included, it was inside the scope of a function.  I've even gone so far as to abstract the function one more scope-layer by adding a class around it for each time any element on the page is included.  In other words I call an instance of a class passing the ElementID which then calls the constructor.  The constructor calls a function in the class passing the ElementID, which then includes the file that has the design functions in it.  

The alternative is to create each element include file as a class.  Before generating the page, the system would have to first take one loop through the elements that will appear on the page to include the relevant classes.  It may then have to make a second loop to actually generate the page by creating instances of the classes each time they are to be displayed.  In this case the structure of the class won't really be taken advantage of.  The person programming the element file will have to be more experienced.  The database driving the system will have to keep more information about each of the elements in order to call instances of the classes.  And, the system may essentially have to take two loops through the page to generate it.

I don't know how else to impress the stop-gap this actually causes.  For our project, this may substantially change the performance of our application.  Out goal to create an easy to implement API for our content management module of our e-business application may be unachievable.  I truly hope you give this serious consideration.

Thanks,
Gary M. Cornelisse
Senior Applications Programmer
Conduit Internet Technologies, Inc.
gcornelisse@conduit-it.com
800.493.5045 x206
814.867.8248 fax
Conduit-IT: Powering Successful eBusiness
http://www.conduit-it.com/

Here's another simple example that causes a parse error.

function add_number($num)
{
    function add_one($num)
    {
        $num++;
        return($num);
    }
    $num = add_one($num);
    return($num);
}

echo add_number(0);
echo add_number(1);

ZendEngine2 supports namespaces.
Functions within function namespace will not be required with namespace.