until -package:numeric-prelude -package:base-prelude -package:hosc -package:numhask -package:foundation -package:free -package:dimensional -is:exact -package:hledger-web -package:termonad 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.