A Roy programming/learning environment with Turtle Graphics, as in the Logo programming language.
Try it online: turtle-roy.heroku.com/
fd 100 | moves 100 pixels forward
lt 45 | turns left 45 degrees
rt 90 | turns right 90 degrees
penup | lifts the pen, no trace left when moving
pendown | lowers the pen again for drawing
setshape "rocket-large" | changes the cursor. available (with and without -large): butterfly, car, fairy, formula, princess, rocket, turtle
clear | clear the paper and reset turtle to center
home | reset the turtle to center
say "wat" | speak!
print "x" | print to console
login "raimo" | login as "raimo" (this is the author name in your saved work)
save "asdf" | save current work as "asdf"
open "asdf" | open saved work "asdf" (presuming you've saved with this name and current author name)
whoami | show the author name of the logged-in user (this is just saved in a cookie)
ls | list your saved works
play c | plays the note C
play c 500 | plays the note C for 500 milliseconds
play c*2 | plays the note C2 (frequency = C * 2)
sequence [fd 100, rt 90] | 100 pixels forward, then right turn
s [fd 100, rt 90] | same as above
repeat 4 (say "hello") | says "hello" 5 times
r 4 (say "hello") | same as above
par [play c, play e] | playes notes C and E in parallel
bg "red" | change background color (red, rgb(255,0,0), #FF0000)
color "red" | change pen color (red, rgb(255,0,0), #FF0000)
text "HELLO" | draw the text "HELLO" beside the turtle
font "40px Arial" | changes to the 40px Arial font
In addition to this, you may use the full Roy programming language.
Bunch of examples available in the demo menu. Some more stuff here.
Basic Turtle commands
fd 100
lt 90
rt 45
Square
let square = repeat 4 (sequence[fd 50, lt 90])
square
Flower
let flower = repeat 36 (sequence[rt 10, square])
flower
Math
3 + 4
3 / 4
let factorial n = if n==1 then 1 else n * (factorial n - 1)
factorial 12
Strings
"apple" ++ "sauce"
"apple" + 10 (won't compile)
Lists
range 1 99
times 100 "lol"
head [1,2,3]
tail [1,2,3]
concat [1,2,3] [4,5,6]
length [1,2,3]
empty []
let reverse xs = if (empty xs) then [] else concat (reverse (tail xs)) [head xs]
reverse [1,2,3]
sum [1,2,3]
map (\x -> x * 2) [1,2,3]
filter (\x -> x > 1) [1,2,3]
foldl (\x y -> x * y) 1 [1,2,3]
./start
Thanks to Miikka "arcatan" Koskinen for creating tryroy, from where I shamelessly stole the Roy browser REPL.
Thanks to Brian McKenna for the Roy language and support.
See origins of the cursor images from src/main/webapp/images/image-sources.txt