Question

It’s easier just to give a code sample:

private $ParseRuleMap = array();

public function __construct( $rules ) {
    foreach( $rules as $which=>$rule ) {
        $mapping = $rule->getMinimumMatchables();

        foreach( $mapping as $match ) {
            $rulelvl &= $this->ParseRuleMap;    // Fun begins here

             $len = strlen($match);
            for( $i=0; $i<$len; $i++ ) {
                if( !isset($rulelvl[ $match[$i] ]) ) {
                    $rulelvl[ $match[$i] ] = array();
                }
                $rulelvl &= $rulelvl[ $match[$i] ]; // Here too!
            }

            // ... other code here ...
        }
    }
}

I get the following error spamming frequently (for the above commented lines):

PHP Warning: Cannot use a scalar value as an array in parser.php on line 35

Am I misunderstanding how reference assignment works here? To (try) to be clear, $rulelvl is supposed to iterate down through a given line of $this->ParseRuleMap‘s sub-arrays via. reference-assignment.

Answer 1

&= is a bitwise operator (bitwise “and” and assign) not the reference operator

Change your code as this:

$rulelvl = &$this->ParseRuleMap;    // note the = &