A place in a Masu grid, in the grid's own terms (rows by their ids,
columns by their keys, never screen pixels, as each person has their
own order, filters and scroll): where a person is, where their
pointer is, where an agent goes (Issho.Motion), what an app keeps
of them. Its format is part of Masu's public API, and only grows.
%{"cell" => [row_id, key]} # a cell
%{"range" => %{"rows" => [row_id, ...], "keys" => [key, ...]}}
%{"cell" => [row_id, key], "range" => %{...}} # a range, from a cell
%{"cell" => [row_id, key], "x" => 0.5, "y" => 0.5} # a pointer in a cellA row id is a string or an integer, as the grid sends its rows; x
and y are where in the cell, from 0 to 1. A range names at most 500
rows. In the room, it is the "at" of a place of the grid's document:
%{"doc" => "notebook:42/tasks", "at" => %{"cell" => [7, "status"]}}.