public Either <Null, Point, LineSegment> IntersectWithSegment(LineSegment lineSegment)
{
return(new Line(this).IntersectWithSegment(lineSegment).Switch <Either <Null, Point, LineSegment> >
(
@null => @null,
point =>
{
if (point == BasePoint || BasePoint.DirectionTo(point) == Direction)
{
return point;
}
return Null.Instance;
},
segment =>
{
var points = segment.EndPoints
.Where(point =>
{
var towardsEndPoint = new Direction(BasePoint, point);
return towardsEndPoint == Direction || point == BasePoint;
})
.ToList();
if (points.Count == 2)
{
return segment;
}
if (points.Count == 1)
{
var segmentPoint = points[0];
if (segmentPoint != BasePoint)
{
return new LineSegment(BasePoint, segmentPoint);
}
return segmentPoint;
}
return Null.Instance;
}
));
}
