What are "notifications" (as currently implemented) in this category theoretical understanding of Are.na?
And what if they were also blocks?
connection of connections, i.e. the functor category is something that deserves further consideration, especially if we take all comments as connection arrows that enrich beyond the initial connection. not only would this open some interesting possibilities (channels that include exogenous connections or comments), but it essentially amounts to a reduction in complexity, from two constructors (objects and connections), to one (connections are objects of type "connection").
Connections are morphisms going from A → B.
(B can be equal to A, since a channel can be added to itself)
Comments and block/channel meta-data are morphisms going from A → A. (comments are presumably moving to connections, so subject to change)
Channels, blocks, users, and connections are all objects, with types channel, block, user, and connection, respectively.