:: Ord a => [a] -> [a] -package:stm-containers -package:statistics -package:basement -package:vector-algorithms -is:exact -package:extra -package:errors -package:hedgehog -package:integration -package:ghc -package:witherable 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.