[Haskell-cafe] tokenize parser combinators and free applicatives

Hi all on [1] it is said the following "Dealing with whitespace and comments is awkward in the parser; you need to wrap everything in a token combinator. (If you decide to do that, at least use a free applicative functor to ensure that you don’t forget to consume that whitespace)." Reading on `free` the def of Ap, frankly I don't see how can the free applicative be used for this. Anybody could drop a hint? I would appreciate it. [1]: https://ro-che.info/articles/2015-01-02-lexical-analysis -- Ruben