collections are kinda underspecced tbh [link]

loosely inspired by the submission of FEP-5bf0 Collection sorting and filtering

filtering [link]

you could pre-create collections that contain a subset of items, but there’s no way to dynamically do server-side filtering; this has to be done client-side by downloading the entire collection and creating any useful indices

sorting [link]

OrderedCollection is mandated reverse-chronological but it should have been possible to specify the ordering

taking schema.org/ItemList and schema.org/ListItem as prior art:

• ListItem.position is the index
• ItemList.itemListOrder is the type of ordering
  • itemListOrderAscending
  • itemListOrderDescending
  • itemListUnordered

what might this imply is needed for activitypub?

• orderedBy?
  • what about multiple ordering criteria? SQL has ORDER BY
  • actually, is a query language a good fit here?
• reversed? more like order: Ascending or order: Descending?

querying [link]

how do you tell if an arbitrary object is included in a collection or not? without iterating over the entire collection, that is.

constraining range [link]

how do you know what a collection contains?