Description:
------------
I seem to be pushed into a wall where I require an array to only execute functions (in-line and in general) in an array value if it's requested. I realize that I may be able to do this via OOP and ArrayAccess, however I find it's not actually able to provide me with what I need. See the test script for an example of what I'm aiming for.

Test script:
---------------
<?
$var = "Before";

function getVar(){
    global $var;
    return $var;
}

$array = Array(
    "variableA" => "A: " . getVar(),
    "variableB" ~> "B: " . getVar() //~> in place of =>
);

$var = "After";

echo $array['variableA']; //Would echo 'A: Before'
echo $array['variableB']; //Would echo 'B: After'
?>

Expected result:
----------------
$array['variableA'] Would equal 'A: Before'
$array['variableB'] Would equal 'B: After'