Add geometry crate with Point and Direction

2022/geometry/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "geometry"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

2022/geometry/src/lib.rs

@@ -0,0 +1,66 @@
+#[derive(Clone, Copy, Debug)]
+pub enum Direction {
+    North,
+    East,
+    South,
+    West,
+}
+
+impl Direction {
+    pub fn all() -> &'static [Direction] {
+        &[
+            Direction::North,
+            Direction::East,
+            Direction::South,
+            Direction::West,
+        ]
+    }
+
+    pub fn from_relative_direction(letter: &str) -> Option<Direction> {
+        match letter {
+            "U" | "u" => Some(Direction::North),
+            "R" | "r" => Some(Direction::East),
+            "D" | "d" => Some(Direction::South),
+            "L" | "l" => Some(Direction::West),
+            _ => None,
+        }
+    }
+}
+
+/**
+ * A point in standard coordinates, where Y values grow in the positively in the North direction.
+ */
+#[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+pub struct Point {
+    pub x: i32,
+    pub y: i32,
+}
+
+impl Point {
+    pub fn zero() -> Point {
+        Point::new(0, 0)
+    }
+
+    pub fn new(x: i32, y: i32) -> Point {
+        Point { x, y }
+    }
+
+    pub fn distance_to(&self, other: &Point) -> (i32, i32) {
+        (other.x - self.x, other.y - self.y)
+    }
+
+    pub fn move_by_one_in(&mut self, direction: Direction) {
+        match direction {
+            Direction::North => self.y += 1,
+            Direction::East => self.x += 1,
+            Direction::South => self.y -= 1,
+            Direction::West => self.x -= 1,
+        }
+    }
+}
+
+impl std::fmt::Display for Point {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "({}, {})", self.x, self.y)
+    }
+}