until -package:numeric-prelude -package:language-bash -package:clash-prelude -package:utility-ht -package:mixed-types-num -package:snap-core -package:yesod-paginator -package:free -package:hedgehog -package:ghc-lib-parser -package:base 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.