methods.rs

impl Point {
    fn sum( &self ) -> float { self.x + self.y }
    fn sqsum( &self ) -> float { self.x * self.x + self.y * self.y }
    fn sub( &self, other: float ) -> Point { Point { x:self.x - other, y:self.y - other } }
    fn mul (&self, other: float ) -> Point { Point { x:self.x * other, y:self.y * other } }
    fn add( &self, other: float ) -> Point {  Point { x:self.x + other, y:self.y + other } }
}