until -package:numeric-prelude -package:language-bash -package:base-compat -package:utility-ht -is:exact -package:base-prelude -package:ghc-lib-parser -package:protolude -package:streaming -package:conferer 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.