:: Ord a => [a] -> [a] -package:html-entities -package:witherable -package:errors -package:ghc -package:incipit-base -package:safe -package:imports -package:mono-traversable -package:hedgehog is:exact -package:basement -package:extra 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.