The Weird and The Wonderful

class Listalizer {

    public static function listalize( $convert, &$data ) {
        if ( is_object( $data ) ) {
            try {
                $data = call_user_func( $convert, $data );
            } catch ( \Exception $ex ) {
                try {
                    trigger_error( "listalize: Callable " . self::callable2String( $convert )
                        . " caused an exception: " . $ex->getMessage(), E_USER_WARNING );
                } catch ( \Exception $exx ) {
                    // Argh! We *can't* throw an exception!
                    $exx = (object)$exx; // this is just a breakpoint anchor.
                }

                $data = false;
            }
        }

        if ( is_array( $data ) || $data instanceof \ArrayObject ) {
            foreach ( $data as $key => &$value ) {
                self::listalize( $convert, $value );
            }
        }
    }

    public static function objectify( $convert, &$data, $role = null ) {
        if ( is_array( $data ) ) {
            try {
                $data = call_user_func( $convert, $data, $role );
            } catch ( \Exception $ex ) {
                try {
                    trigger_error( "objectify: Callable " . self::callable2String( $convert )
                        . " caused an exception: " . $ex->getMessage(), E_USER_WARNING );
                } catch ( \Exception $exx ) {
                    // Argh! We *can't* throw an exception!
                    $exx = (object)$exx; // this is just a breakpoint anchor.
                }

                $data = false;
            }
        }

        if ( is_array( $data ) || $data instanceof \ArrayObject ) {
            foreach ( $data as $key => &$value ) {
                self::objectify( $convert, $value, $key );
            }
        }
    }

    public static function callable2String( $callable ) {
        if ( is_array( $callable ) && count( $callable ) === 1 ) {
            $callable = array_pop( $callable );
        }

        if ( is_string( $callable ) ) {
            return $callable;
        } elseif ( is_object( $callable ) ) {
            return get_class( $callable ) . '->__invoke';
        } elseif ( is_array( $callable ) ) {
            $target = $callable[0];
            $method = $callable[1];

            if ( is_string( $target ) ) {
                return "$target::$method";
            } elseif ( is_object( $target ) ) {
                $class = get_class( $target );
                return "$class->$method";
            } else {
                return '(array)';
            }
        }

        return '(' . var_export( $callable, true ) . ')';
    }
}