Current page variable in query

I’d like use a query to filter pages with “category” set to the current page slug:

query: site.index.filterBy("category", page.slug)

Shouldn’t page.slug be the slug of the current page? Or is something like that not possible?

EDIT: I solved it with a custom page method for now:

'categoryPages' => function() {
  $category = $this->slug();
  $pages = site()->index()->filterBy("intendedTemplate", "default");
  $categoryPages = $pages->filterBy("category", $category);
  return $categoryPages;