application/octet-stream
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950 B
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26 lines
;;; Nujel - Copyright (C) 2020-2021 - Benjamin Vincent Schulenburg
;;; This project uses the MIT license, a copy should be included under /LICENSE
;;;
;;; A very simple pseudo random number generator, suitable for the illusion of
;;; randomness
(defclass rng
"A simple RNG"
:export
(defn new (self seed)
(when-not seed (set! seed (bit-xor (time) (time/milliseconds))))
{ :seed seed :prototype* self })
(defn seed! (self seed)
"Set a new seed value for the RNG"
(set! self :seed seed))
(defn rng! (self)
"Generate a random integer"
(set! self :seed (+ 12345 (* (ref self :seed) 1103515245)))
(bit-or (bit-shift-left (bit-and (ref self :seed) #xFFFF) 16)
(bit-and (bit-shift-right (ref self :seed) 16) #xFFFF)))
(defn int (self max)
"Return a value from 0 to MAX, or, if left out, a random int"
(if max (rem (abs (:rng! self)) max) (:rng! self))))
