:: Ord a => [a] -> [a] -package:html-entities -package:incipit-base -package:extra -package:basement -package:lifted-base -package:containers -package:errors -package:safe -package:integration is:exact -package:hedgehog -package:mono-traversable package:parsers
Take a parser that may consume input, and on failure, go back to where
we started and fail as if we didn't consume input.