sidef-scripts/Image/hilbert_curve.sf

#!/usr/bin/ruby

# https://rosettacode.org/wiki/Hilbert_curve

include('LSystem/LSystem.sf')

var rules = Hash(
    a => '-bF+aFa+Fb-',
    b => '+aF-bFb-Fa+',
)

var lsys = LSystem(
    width:  600,
    height: 600,

    xoff: -50,
    yoff: -50,

    len:   8,
    angle: 90,
    color: 'dark green',
)

lsys.execute('a', 6, "hilbert_curve.png", rules)