:: Ord a => [a] -> [a] -package:html-entities -is:exact -package:witherable -package:incipit-base -package:ghc -package:containers -package:hedgehog -package:extra -package:generic-deriving -package:Cabal-syntax -package:Cabal is:exact 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.