{%- comment -%}
  Sets `page_kind` to one of: homepage | posts | tabs | other_pages.

  Used to index the per-surface toggles in _config.yml, e.g.
  `site.right_sidebar.disclaimer.enable[page_kind]`. Keeping the test in one
  place means the panels cannot drift apart on what counts as a "tab".

  The layout name settles the first two: 'home' for the home page, 'post' for
  posts and drafts. Tabs are matched on the collection instead, because the
  seven of them use seven different layouts (page, archives, categories, books,
  poem-index, tags), so there is no single layout name to test. Whatever is left
  -- individual poems, book chapters -- falls through to other_pages.

  An assign inside an include is visible to the caller, so including this file
  is enough to define `page_kind`.

  NB: no literal Liquid tags in this comment -- a comment block still tokenises
  the tags inside it, so an argument-less assign here is a parse error.
{%- endcomment -%}
{%- if page.layout == 'home' -%}
  {%- assign page_kind = 'homepage' -%}
{%- elsif page.layout == 'post' -%}
  {%- assign page_kind = 'posts' -%}
{%- elsif page.collection == 'tabs' -%}
  {%- assign page_kind = 'tabs' -%}
{%- else -%}
  {%- assign page_kind = 'other_pages' -%}
{%- endif -%}