until -package:numeric-prelude -package:yesod-paginator -package:prelude-compat -package:numhask -package:util -package:ghc-lib-parser -package:base-prelude -package:clash-prelude -package:utility-ht -package:extra 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.