until -package:numeric-prelude -package:language-bash -package:clash-prelude -package:extra -package:free -package:monad-loops -package:hedgehog -package:simple-prompt -package:ghc-lib-parser 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.