make $node object in pattern

IT is not possible to pass variables to eval'd code, I know, but at least we could provide some featured APIs for this?

I now depend on helpers module, for example:

/**
 * Find out if the current page is a node page.
 * @return TRUE if the page is a node, FALSE if it is another page.
 */
function is_node_page() {
 if (arg(0) == 'node' && is_numeric(arg(1))) {
   return TRUE;
 }
 return FALSE;
}

/**
 * Grab the current 'active' node
 * An active node is the one node 123 as shown on page with path node/123, or
 * its aliased path(s).
 * @return $node object if the page is a node, empty $node object if it is not a
 * node, or if we cannot see it, for any valid reason.
 */
function node_load_current() {
 $node = new stdClass();

 if (is_node_page()) {
   $node = node_load(arg(1));
 }

 return $node;
}

But we need something that makes $node available on_validate and _preview.