  Field-based coordination has been proposed as a model for coordinating
collective adaptive systems, promoting a view of distributed computations as
functions manipulating data structures spread over space and evolving over
time, called computational fields. The field calculus is a formal foundation
for field computations, providing specific constructs for evolution (time) and
neighbor interaction (space), which are handled by separate operators (called
rep and nbr, respectively). This approach, however, intrinsically limits the
speed of information propagation that can be achieved by their combined use. In
this paper, we propose a new field-based coordination operator called share,
which captures the space-time nature of field computations in a single operator
that declaratively achieves: (i) observation of neighbors' values; (ii)
reduction to a single local value; and (iii) update and converse sharing to
neighbors of a local variable. We show that for an important class of
self-stabilising computations, share can replace all occurrences of rep and nbr
constructs. In addition to conceptual economy, use of the share operator also
allows many prior field calculus algorithms to be greatly accelerated, which we
validate empirically with simulations of frequently used network propagation
and collection algorithms.

Distributed, Parallel, and Cluster Computing;Logic in Computer Science;Programming Languages