random_roll.clj

(ns random-roll)
; My friends: "Let's play this stupid game over zoom. Everyone needs some dice"
; Me 10 minutes later:


(defn single-roll [sides]
  (inc (rand-int sides)))


(defn roll
  ([sides] (roll 1 sides))

  ([times sides]
    (let [rolls (repeatedly times #(single-roll sides))
          sum (reduce + rolls)]
      {:sum sum :rolls rolls}))

  ([times sides modifier]
    (let [result (roll times sides)]
     (assoc result :modified (+ modifier (:sum result))))))


(comment
  ; This follows D&D markup syntax for dice rolls
  ; Roll a d20
  (roll 20)
  ; => {:sum 6 :rolls '(6)}


  ; Roll 3d6
  (roll 3 6)
  ; => {:sum 9 :rolls '(5 1 3)}
  

  ; Roll 2d8 + 1
  (roll 2 8 1))
  ; => {:sum 10, :rolls '(7 3), :modified 11}