Turtle Graphics in The Yak's varient of Logo Language.
Download the app: http://yak.net/repos/tmp/ATurtleYak.apk
Index variables i, j, k automatically created in loops. i is the index of the outermost loop; j the second outer-most loop, etc. (This means that a single i is no longer a roman numeral). There are no other variables.
Binary operators + - * / % != < <= == > >=
They can be used where N appears below.
Execution order is strictly left to right (no precedence).
c N -- color (n is RGB decimal; i.e. 0=black 999=white 900=red 90=green 9=blue
u -- pen up
d -- pen down
f N -- go forward N steps (the only way to draw)
l N -- go left n degrees
r N -- go right n degrees
( code... ) N -- repeat code... N times
/z -- call box z as a subroutine (no space after the /)
Separate all tokens by white space! Even "(" and ")" and "+" etc.
Numbers can be decimal or roman numerals (except i is an index variable).