# Wrap a rectangle with circles of the same size to produce
# a tubular shape.
wrap(R<20>) with {
left => C<10>,
right => C<10>,
# Place a smiley 8 units down from the center, just for lolz.
angle(90) +8 => R<3>(smiley),
# Cut-out a cam shape from the center.
center => negative {
wrap(R<20, 5>) with {
left => C<2.5>,
right => C<2.5>,
}
},
}