11. Macros

Activity 11.01: A Tennis CSV Macro

Solution:

1. Here is one possibility for the expanded code:

   (with-open [reader (io/reader csv)]
     (->> (csv/read-csv reader)
          sc/mappify
          (sc/cast-with {:winner_games_won sc/->int
                         :loser_games_won sc/->int})
          (map #(assoc % :games_diff (- (:winner_games_won %) (:loser_games_won %))))
          (filter #(> (:games_diff %) threshold))
          (map #(select-keys % [:winner_name :loser_name :games_diff]))
          doall))

   This should be taken as a rough sketch for the final output.  

2. Set up your project. The deps.edn file should look like this:

   {:deps
   &...