Turtle Roy

A Roy programming/learning environment with Turtle Graphics, as in the Logo programming language.

Try it online: turtle-roy.heroku.com/

Turtle Roy API

fd x    | moves x pixels forward
lt x    | turns left x degrees
rt x    | turns right x degrees
penup   | lifts the pen, no trace left when moving
pendown | lowers the pen again for drawing
clear   | clear the paper and reset turtle to center

Examples

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 (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
head [1,2,3]
tail [1,2,3]
concat [1,2,3] [4,5,6]
length [1,2,3]
let reverse xs = if (empty xs) then [] else concat (reverse (tail xs)) [head xs]
reverse [1,2,3]

Running

./sbt ~container:start

Credits

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.