/**
* Helper method to retrieve a pointer inside a given data structure
* using a given segment. Returns null if there is no such segment.
*
* @param var $ptr
* @param string $segment
* @return var
*/
protected function pointer($ptr, $segment)
{
if ($ptr instanceof \ArrayAccess) {
return $ptr->offsetExists($segment) ? $ptr->offsetGet($segment) : null;
} else {
if (is_object($ptr)) {
$class = typeof($ptr);
// 1. Try public field named <segment>
if ($class->hasField($segment)) {
$field = $class->getField($segment);
if ($field->getModifiers() & MODIFIER_PUBLIC) {
return $field->get($ptr);
}
}
// 2. Try public method named <segment>
if ($class->hasMethod($segment)) {
$method = $class->getMethod($segment);
if ($method->getModifiers() & MODIFIER_PUBLIC) {
return $method->invoke($ptr);
}
}
// 3. Try accessor named get<segment>()
if ($class->hasMethod($getter = 'get' . $segment)) {
$method = $class->getMethod($getter);
if ($method->getModifiers() & MODIFIER_PUBLIC) {
return $method->invoke($ptr);
}
}
// Non applicable - give up
return null;
} else {
if (isset($ptr[$segment])) {
return $ptr[$segment];
} else {
if ('length' === $segment) {
return sizeof($ptr);
} else {
return null;
}
}
}
}
}
