updating.carp

;; A slightly bigger example of how to work with structs and arrays that change

(use IO)
(Project.no-echo)

(deftype Pos
    [x Float
     y Float])

(defn incf [x]
  (Float.+ x 1.0f))

(defmodule Pos
  (defn move [pos]
    (=> pos
        (Pos.update-x &incf)
        (Pos.update-y &incf))))

(deftype Monster
    [pos Pos
     hp Int
     name String])

(defmodule Monster
  (defn init-random [name]
    (Monster.init
     (Pos.init (Float.random-between 0.0f 100.0f)
               (Float.random-between 0.0f 100.0f))
     100
     @name))
  (defn move [monster]
    (Monster.update-pos monster &Pos.move)))

(defn main []
  (do
    ; here we always use the same seed for determinism, for simple random
    ; numbers that change you can for instance use (System.time)
    (Random.seed-from 0.1)
    (let [monsters (Array.copy-map &Monster.init-random &[@"Pegasus" @"Dragon" @"Devil"])]
      (do
        (println (ref (Array.str &monsters)))
        (let [new-monsters (Array.endo-map &Monster.move monsters)]
          (println (ref (Array.str &new-monsters))))))))