:: Ord a => [a] -> [a] -package:html-entities -package:extra -is:exact -package:amazonka-core -is:exact -package:Cabal -package:witherable -package:ghc -package:containers -package:errors -package:lens -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.