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Bowling kata
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(ns bowling) | |
(def empty-state | |
{:frames [] | |
:current-frame [] | |
:score 0 | |
:strike-counter 0 | |
:spare-counter 0}) | |
(defn dec-zero [n] | |
(max 0 (dec n))) | |
(defn roll [{:keys [frames current-frame strike-counter spare-counter score] :as state} | |
pins] | |
(let [last-frame? (= 9 (count frames)) ; TODO: Bunch of rules about the last frame | |
strike? (and (empty? current-frame) (= 10 pins)) | |
spare? (and (seq current-frame) (= 10 (+ (first current-frame) pins))) | |
new-score (cond-> (+ score pins) | |
(or (pos? strike-counter) | |
(pos? spare-counter)) | |
(+ pins)) | |
frame-ended? (or strike? (seq current-frame))] | |
(-> state | |
(assoc :score new-score) | |
(update :strike-counter dec-zero) | |
(update :spare-counter dec-zero) | |
(cond-> strike? (assoc :strike-counter 2) | |
spare? (assoc :spare-counter 1) | |
frame-ended? (-> (update :frames conj (conj current-frame pins)) | |
(assoc :current-frame [])) | |
(not frame-ended?) (update :current-frame conj pins))))) | |
(defn game [rolls] | |
(reduce roll empty-state rolls)) | |
(defn dbg [rolls] | |
(map #(assoc %1 :pins %2) (rest (reductions roll empty-state rolls)) rolls)) | |
(comment | |
;; The example from the description | |
(= 48 (:score (game [10 5 5 9 0]))) | |
;; Debug what is happening at each step | |
(dbg [10 5 5 9 0]) | |
) |
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