First start up the REPL by issuing this command:
clj -Sdeps '{:deps {github-mfikes/e00202b2de7cc2352fedcf92b1fe60dc {:git/url "https://gist.github.com/mfikes/e00202b2de7cc2352fedcf92b1fe60dc" :sha "68ef581813e08a92bd52e7beeea1535ab7b3337f"}}}' -m cljs.main -i @index.cljs -r
Once the REPL is waiting for the browser to connect, if it doesn't automatically, open http://localhost:9000 in your browser.
You will now be running Bocko. The following forms evaluated in the REPL will draw an American flag.
;; Draw 13 stripes cycling over red/white
(doseq [[n c] (take 13
(map vector (range) (cycle [:red :white])))]
(color c)
(let [x1 10
x2 25
y (+ 10 n)]
(hlin x1 x2 y)))
;; Fill in a dark blue field in the corner
(color :dark-blue)
(doseq [x (range 10 19)
y (range 10 17)]
(plot x y))
;; Add some stars to the field by skipping by 2
(color :white)
(doseq [x (range 11 19 2)
y (range 11 17 2)]
(plot x y))