true iff x quacks like an activity, else false.

The URI of the context of an ActivityStreams object is expected to be this literal string.

TODO: write docs

The set of types we will accept as actors.

There’s an explicit set of allowed actor types.

Returns true if x quacks like an actor, else false.

true iff x quacks like a page in a paged collection, else false.

true iff x quacks like a collection of type type, else false.

With one argument, will recognise plain collections and ordered collections, but (currently) not collection pages.

Returns true iff x quacks like an ActivityStreams context, else false.

A context is either 1. the URI (actually an IRI) activitystreams-context-uri, or 2. a collection comprising that URI and a map.

TODO: write docs

true iff x is either a URI or a link, else false.

There are several points in the specification where e.g. the :image property (if present) may be either a link or a URI.

true iff x quacks like a link, else false.

Returns true iff x is recognisably an ActivityStreams object.

NOTE THAT The ActivityStreams spec says:

All properties are optional (including the id and type)

But we are just not having that, because otherwise we’re flying blind. We shall reject objects lacking at least :type. Missing :id keys are tolerable because they represent transient objects, which we expect to handle.

true iff x quacks like a page in an ordered paged collection, else false.

true iff x quacks like an ordered collection, else false.

true iff x is a persistent object.

Transient objects in ActivityPub are not required to have an id key, but persistent ones must have a key, and it must be an IRI (but normally a URI).

true iff x quacks like an unordered collection, else false.

TODO: write docs

The set of types we will accept as verbs.

There’s an explicit set of allowed verb types.