until -package:numeric-prelude -package:streaming -package:util -package:snap-core -package:utility-ht -package:intro -package:basic-prelude -package:xmonad-contrib -package:hledger-web -package:termonad package:dunai
Similar to Yampa's delayed switching. Loses a b in case of an
exception.
Run the first
msf until the second one produces
True
from the output of the first.