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mccraigmccraig 2023-02-01T17:38:42.969159Z
working with promesa.exec.csp ... there's a slight semantic difference in noticed from manifold and core.async in that:
(sp/put ch :foo)
(sp/close! ch)
@(sp/take ch) ;=> nilnil (i.e. the channel closes before the put happens), whereas with similar manifold and core.async sequences the result would be :foo - presumably because they are both doing some synchronous queueing of puts, whereas promesa.exec.csp is parking until there is a consumer and that never happens
i'm not sure this is a bad thing though ... it's easy enough to compensate for, and puting without waiting on the result is perhaps a code smell anywaymccraigmccraig 2023-02-01T17:54:28.642479Z
anyway, i did a promesa.exec.csp based implementation for my manifold-a-like lib, and it mostly works (still got a few test errors to work through): https://github.com/yapsterapp/promisespromises/blob/e1380827b36652a2b8ad6b03b065288f19f573ec/src/prpr3/stream/promesa_csp.cljc
niwinz 2023-02-01T18:34:27.266199Z
yep, it is expected behavior difference, and it depends on the channel type. core.async preserves all pending puts to the channel when you call close!, this is why, after a close you can take! it.
promesa on the other hand, clears all queues on close, and resolves with nil all pending operations.
👍 1
niwinz 2023-02-01T18:35:23.983339Z
if channel was buffered, the result will be different, the value will be put in buffer synchronously and the take will success with expected value after close!
niwinz 2023-02-01T18:35:40.982929Z