

Task
Produce a graphical or ASCII-art representation of a Sierpinski square curve of at least order 3.

var rules = Hash(
    x => 'xF-F+F-xF+F+xF-F+F-x',
)
 
var lsys = LSystem(
    width:  510,
    height: 510,
 
    xoff: -505,
    yoff: -254,
 
    len:   4,
    angle: 90,
    color: 'dark green',
)
 
lsys.execute('F+xF+F+xF', 5, "sierpiński_square_curve.png", rules)