until -package:numeric-prelude -package:base-prelude -package:distribution-opensuse -package:extra -package:snap-core -package:hledger-web -package:util -package:clash-prelude -package:classy-prelude -package:Cabal-syntax -package:prelude-compat 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.