Initial commit

robot-simulator/src/lib.rs

@@ -0,0 +1,77 @@
+// The code below is a stub. Just enough to satisfy the compiler.
+// In order to pass the tests you can add-to or change any of this code.
+
+#[derive(PartialEq, Eq, Debug)]
+pub enum Direction {
+    North,
+    East,
+    South,
+    West,
+}
+
+pub struct Robot {
+    x: i32,
+    y: i32,
+    direction: Direction
+}
+
+impl Robot {
+    pub fn new(x: i32, y: i32, direction: Direction) -> Self {
+        Self {
+            x,
+            y,
+            direction
+        }
+    }
+
+    #[must_use]
+    pub fn turn_right(self) -> Self {
+        match self.direction {
+            Direction::North => Self { direction: Direction::East, ..self },
+            Direction::East => Self { direction: Direction::South, ..self },
+            Direction::South => Self { direction: Direction::West, ..self },
+            Direction::West => Self { direction: Direction::North, ..self }
+        }
+    }
+
+    #[must_use]
+    pub fn turn_left(self) -> Self {
+        match self.direction {
+            Direction::North => Self { direction: Direction::West, ..self },
+            Direction::West => Self { direction: Direction::South, ..self },
+            Direction::South => Self { direction: Direction::East, ..self },
+            Direction::East => Self { direction: Direction::North, ..self },
+        }
+    }
+
+    #[must_use]
+    pub fn advance(self) -> Self {
+        match self.direction {
+            Direction::North => Self { y: self.y + 1, ..self },
+            Direction::West => Self { x: self.x - 1, ..self },
+            Direction::South => Self { y: self.y - 1, ..self },
+            Direction::East => Self { x: self.x + 1, ..self },
+        }
+    }
+
+    #[must_use]
+    pub fn instructions(self, instructions: &str) -> Self {
+        instructions
+            .chars()
+            .fold(self, |robot, ch|
+                match ch {
+                    'L' => robot.turn_left(),
+                    'R' => robot.turn_right(),
+                    'A' => robot.advance(),
+                    _ => robot
+                 })
+    }
+
+    pub fn position(&self) -> (i32, i32) {
+        (self.x, self.y)
+    }
+
+    pub fn direction(&self) -> &Direction {
+        &self.direction
+    }
+}