;; cljrs.core.experimental — APIs that exist for integrators but cannot honour
;; the contract their Clojure namesakes carry, and so are kept out of
;; clojure.core.
;;
;; Nothing here is referred into `user`; reach it with an explicit
;; (require '[cljrs.core.experimental :as x]).
(ns cljrs.core.experimental)
(defmacro future
"Runs body as a task on this isolate's executor and returns a future.
NOT clojure.core/future, and deliberately not interchangeable with it. This
runtime is one thread per isolate, so of the four guarantees the JVM's
`future` makes, this keeps one:
- the body does NOT run in parallel — it is cooperative, and advances only
while this thread is awaiting something
- (deref f) / @f does NOT work — it blocks the one thread the task needs in
order to finish, deadlocking. Read the result with (await f) from an
^:async fn
- dynamic bindings are NOT conveyed to the task; bind inside body if it
needs them
- (future-cancel f) does not interrupt the task, which runs to completion;
what is cancelled is the result, as for a JVM future already past its
interruption point
For work that must actually run in parallel, spawn an isolate and pass values
over an isolate channel."
[& body]
(list 'cljrs.core.experimental/future-call (list 'fn [] (cons 'do body))))