add engine

game/entity.rs

@@ -0,0 +1,107 @@
+#[derive(Clone, Copy, PartialEq)]
+pub struct Cell(u8);
+pub const CELL_EMPTY: Cell = Cell(0);
+pub const CELL_X: Cell = Cell(1);
+pub const CELL_O: Cell = Cell(2);
+
+impl std::fmt::Display for Cell {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        let mut s: &str = " ";
+        if *self == CELL_X {
+            s = "X";
+        } else if *self == CELL_O {
+            s = "O";
+        }
+
+        write!(f, "{}", s)
+    }
+}
+
+pub struct Move {
+    pub x: usize,
+    pub y: usize,
+    pub c: Cell,
+}
+
+pub struct Board {
+    cells: Vec<Cell>,
+    next: Cell,
+}
+
+impl Board {
+    pub fn new() -> Board {
+        return Board {
+            cells: vec![CELL_EMPTY; 9],
+            next: CELL_X,
+        };
+    }
+
+    pub fn reset(&mut self) {
+        self.cells = vec![CELL_EMPTY; 9];
+        self.next = CELL_X;
+    }
+
+    pub fn put(&mut self, m: Move) -> bool {
+        let i = m.x * 1 + m.y * 3;
+        if self.cells[i] != CELL_EMPTY {
+            return false;
+        }
+
+        self.cells[i] = m.c;
+
+        return true;
+    }
+
+    pub fn has_winner(&self) -> Cell {
+        // rows and cols
+        for i in 0..3 {
+            if self.cells[i] == self.cells[i + 3] && self.cells[i] == self.cells[i + 6] {
+                return self.cells[i];
+            } else if self.cells[i * 3] == self.cells[i * 3 + 1]
+                && self.cells[i * 3] == self.cells[i * 3 + 2]
+            {
+                return self.cells[i * 3];
+            }
+        }
+
+        // diagonals
+        if self.cells[0] == self.cells[4] && self.cells[0] == self.cells[8] {
+            return self.cells[0];
+        }
+
+        if self.cells[2] == self.cells[4] && self.cells[2] == self.cells[6] {
+            return self.cells[2];
+        }
+
+        // no winner
+        return CELL_EMPTY;
+    }
+}
+
+impl std::fmt::Display for Board {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        let mut s = String::new();
+
+        s.push_str("┌─┬─┬─┐\n");
+        for i in 0..3 {
+            s.push_str(&format!(
+                "│{}│{}│{}│\n",
+                self.cells[i * 3],
+                self.cells[i * 3 + 1],
+                self.cells[i * 3 + 2]
+            ));
+            if i < 2 {
+                s.push_str("├─┼─┼─┤\n");
+            }
+        }
+        s.push_str("└─┴─┴─┘\n");
+
+        let w = self.has_winner();
+        if w != CELL_EMPTY {
+            s.push_str(&format!("The winner is {w}"));
+        } else {
+            s.push_str(&format!("Next: {}", self.next));
+        }
+        write!(f, "{s}")
+    }
+}

game/mod.rs

@@ -1,2 +1,2 @@
-mod ttt;
-pub use ttt::{Board, Cell};
+mod entity;
+pub use entity::{Board, Cell, Move, CELL_EMPTY, CELL_O, CELL_X};

game/ttt.rs

@@ -1,29 +0,0 @@
-use std::io::Empty;
-
-pub enum Cell {
-    Empty,
-    X,
-    O,
-}
-
-pub struct Board {
-    cells: Vec<Cell>,
-    next: Cell,
-}
-
-impl Board {
-    pub fn new() -> Board {
-        return Board {
-            cells: Vec::new(),
-            next: Cell::X,
-        };
-    }
-
-    pub fn put(&self, x: usize, y: usize, _: Cell) -> bool {
-        return false;
-    }
-
-    pub fn winner(self) -> Cell {
-        return Cell::Empty;
-    }
-}