until -package:numeric-prelude -package:streaming -package:yesod-paginator -package:mixed-types-num -package:dimensional -is:exact -package:protolude -package:termonad -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.