§ Big list of common lisp

;; to change package, goto SLIME, type `,` for `, set package`.
(declaim (optimize (speed 0) (safety 3) (debug 3)))
(defpackage :rasterizer1 (:use :common-lisp))

§ Toys

Special variables (Mutable globals) should be surrounded by asterisks. These are called earmuffs. (defparameter positions (make-array ...))
(assert (condition)
;; https://lispcookbook.github.io/cl-cookbook/error_handling.html#handler-case-vs-handler-bind
(defun divide (x y)
  (assert (not (zerop y))
          (y)   ;; list of values that we can change.
          "Y can not be zero. Please change it") ;; custom error message.
  (/ x y))
(ql:quickload "str")