V8/usr/src/cmd/ideal/lib/wavy

.IS
wavy {
	var start, end, perp, pt1, pt2, ht;
	perp = (0,1)*(start - end)/abs(start - end);
	pt1 = 0.25[start,end] + perp*ht;
	pt2 = 0.75[start,end] - perp*ht;
	conn start to pt1 to pt2 to end;
}
.IE