Overload * and / for Point

extension-rust/src/geometry.rs

@@ -1,4 +1,4 @@
-use std::ops::{Add, Sub};
+use std::ops::{Add, Sub, Mul, Div};
 
 #[derive(Debug, PartialEq)]
 pub struct Point {
@@ -10,32 +10,79 @@ impl Point {
     fn origin() -> Point {
         Point { x: 0.0, y: 0.0 }
     }
+    fn magnitude(self) -> f64 {
+        (self.x * self.x + self.y * self.y).sqrt()
+    }
 }
 
 impl Add for Point {
     type Output = Self;
-
     fn add(self, other: Self) -> Self {
         Self {x: self.x + other.x, y: self.y + other.y}
     }
 }
 
 impl Sub for Point {
     type Output = Self;
-
     fn sub(self, other: Self) -> Self {
         Self {x: self.x - other.x, y: self.y - other.y}
     }
 }
 
+impl Mul<f64> for Point {
+    type Output = Self;
+    fn mul(self, other: f64) -> Self {
+        Self {x: self.x * other, y: self.y * other}
+    }
+}
+
+impl Mul<Point> for f64 {
+    type Output = Point;
+    fn mul(self, other: Point) -> Point {
+        Point {x: self * other.x, y: self * other.y}
+    }
+}
+
+impl Div<f64> for Point {
+    type Output = Self;
+    fn div(self, other: f64) -> Self {
+        Self {x: self.x / other, y: self.y / other}
+    }
+}
+
 mod tests {
     use super::*;
 
     #[test]
-    fn test_add() {
+    fn magnitude() {
+        assert_eq!(5.0, Point{y: 3.0, x: 4.0}.magnitude());
+        assert_eq!(13.0, Point{y: 5.0, x: 12.0}.magnitude());
+        assert_eq!(65.0, Point{y: -33.0, x: -56.0}.magnitude());
+    }
+
+    #[test]
+    fn add() {
+        let a = Point{x: 1.0, y: 2.0};
+        let b = Point{x: 1.0, y: 0.0};
+        assert_eq!(a + b, Point{x: 2.0, y: 2.0});
+    }
+
+    #[test]
+    fn subtract() {
         let a = Point{x: 1.0, y: 2.0};
         let b = Point{x: 1.0, y: 0.0};
-        assert_eq!(a + b, Point{x: 2.0, y: 2.0})
+        assert_eq!(b - a, Point{x: 0.0, y: -2.0});
+    }
+
+    #[test]
+    fn mul() {
+        assert_eq!(Point{x: 1.3, y: 2.0} * 4.0, Point{x: 5.2, y: 8.0});
+        assert_eq!(4.0 * Point{x: 1.3, y: 2.0}, Point{x: 5.2, y: 8.0});
+    }
+
+    #[test]
+    fn div() {
+        assert_eq!(Point{x: 7.0, y: 2.0} / 2.0, Point{x: 3.5, y: 1.0});
     }
 
 }