Scoped resources and deferred closure executions for Nushell.
Experimental.
(You can run it from this folder with nu example.nu)
use rescope *
use std log
log set-level 0 # activate debug logs
rescope {|sc1|
# We open a temp folder whose finalization (removal)
# is scheduled at the end of this scope (closure):
let path = mkscoped file -s $sc1 { mktemp --directory }
# We schedule to print "Bye!" at the end of this closure:
"Bye!" | defer -s $sc1 { print $in }
rescope {|sc2|
# Here, no `-s` is given: finalizers are by defaut attached to the
# innermost scope. So here, sc2:
let job1 = mkscoped job { sleep 10sec }
# But we can also target the outer scope:
let job2 = mkscoped job -s $sc1 { sleep 10sec }
} # End of sc2: $job1 gets killed
} # End of sc1: $job2 gets killed, then "Bye!" is printed, then $path gets deleted
# (Resources are always finalized in the order inverse to their creation)