guys - not sure of this is the right place to ask but I have a small problem writing the equivalent of Unix tail in core.async

if I have process writing to the file when I run tail, it all works as expected

if the writing process starts after I run tail, it does not output anything

I have a feeling I’m missing something obvious so wondered if another pair of eyes (or many pairs of eyes!) could help

please ignore this question I just realised that my failing test truncated the file, so in fact the code is OK and my test was faulty

sorry to have bothered everyone 😉

(btw I know that this is actually the equivalent of tail -1f rather than a proper equivalent of tail; sue me)

on that note, you shouldn't do blocking I/O in go blocks at all, only channel operations. In thread blocks there is no use-case restriction

of course this is not enforced programmatically, but if you do enough I/O in go block your will encounter deadlocks @raymcdermott

@ghadi: I take your general point but this loop is just reading a file so I don’t think it’s possible to generate a deadlock - further advice welcome

you'll certainly need more I/O to cause the deadlock

ok, just making sure I wasn't missing a more subtle infra aspect