This is a major change to the previous design, and also a change with
respect to the semantics in the ESOP 2016 paper. All the complexity of
echo-cancellation is stripped out of the core dataspace semantics, and
the relaying protocol is changed from one constructor, `at-meta`, to
two, `inbound` and `outbound`. The relay connecting a dataspace to its
container is now completely symmetric with the contained actors: it
initially asserts interest in what it is to relay, just like any other
actor would. Dataspaces no longer treat relaying specially.
This commit has updated all (I think) of the non-graphical examples. The
graphical code remains to be done in a following commit.
A store is like a parameter, except stores are independent of each
other, unlike parameters which are bundled together into a single
parameterization. This was observable in cases like the
example-action-after-suspension code checked in here, where dataflow
invoked a script, which parameterized current-dataflow-subject-id.
This captured *too much* of things like the pending-patch and
pending-actions. Subsequent `schedule-action!` calls' effects were
then lost.
Introduced expanders for events (define-event-expander) and for
assertion-patterns (define-assertion-expander).
Introduced convenience syntax and utilities in web.rkt for working
with web requests.
Support nested bindings in assertion-patterns for message events
(only).
This makes rising-edge checks happen only when *fields* change, rather
than every turn. It also means that if a script causes a relevant
field change, the rising-edge check will definitely be performed
before the end of the turn.
A potential downside is that a rising-edge check could schedule a
script which triggers the same rising-edge check, causing an infinite
loop in `run-scripts!`.
This is Syndicate/Racket v2, modeled more closely after Syndicate/js.
Facets and Endpoints are now contained within a single actor, unlike
Syndicate/Racket v1, where a linkage protocol between multiple actors
was used. The approach to actor and facet state has been revised as a
consequence.
Almost all the examples using syndicate/actor have been updated.
This makes (on (asserted)), (on (retracted)) and (during) behave as if
they are *grouping* by their named captures, which is what we want. It
gives a much easier to understand programming model. Note the
differences in execution of example-partial-retraction.rkt before and
after this patch. This patch gives example-partial-retraction.rkt, and
programs like it, a more natural behaviour.
Add support for encoding prefab structs as JSON objects.
Remove linkage & at-meta from patches inside broker dataspace. This is
ugly, and deserves to be revisited in future.
Fix a bug where using trie-prune-branch was incorrect, and
trie-subtract should have been used instead.
Factor out support/struct.rkt.