Refactor

src/agents/diffuse.rs

@@ -1,3 +1,5 @@
+use anyhow::Result;
+
 use super::{MinimizerAgent, RandomAgent};
 use crate::{
 	board::{Board, PlayerAction},
@@ -67,7 +69,7 @@ impl DiffuseAgent {
 }
 
 impl MinimizerAgent for DiffuseAgent {
-	fn step_min(&mut self, board: &Board) -> PlayerAction {
+	fn step_min(&mut self, board: &Board) -> Result<PlayerAction> {
 		let symb = [Symb::Minus, Symb::Times, Symb::Plus, Symb::Div]
 			.iter()
 			.filter(|x| !board.contains(**x))
@@ -77,7 +79,7 @@ impl MinimizerAgent for DiffuseAgent {
 			// No symbols available, play a random number
 			RandomAgent {}.step_min(board)
 		} else {
-			self.step_symb(board, *symb.unwrap())
+			Ok(self.step_symb(board, *symb.unwrap()))
 		}
 	}
 }

src/agents/mod.rs

@@ -1,19 +1,22 @@
 mod diffuse;
 mod minmaxtree;
+mod player;
 mod random;
 
 pub use diffuse::DiffuseAgent;
 pub use minmaxtree::MinMaxTree;
+pub use player::PlayerAgent;
 pub use random::RandomAgent;
 
 use crate::board::{Board, PlayerAction};
+use anyhow::Result;
 
 /// An agent that tries to minimize the value of a board.
 pub trait MinimizerAgent {
-	fn step_min(&mut self, board: &Board) -> PlayerAction;
+	fn step_min(&mut self, board: &Board) -> Result<PlayerAction>;
 }
 
 /// An agent that tries to maximize the value of a board.
 pub trait MaximizerAgent {
-	fn step_max(&mut self, board: &Board) -> PlayerAction;
+	fn step_max(&mut self, board: &Board) -> Result<PlayerAction>;
 }

src/agents/player.rs

@@ -0,0 +1,172 @@
+use std::io::{stdin, stdout, Write};
+
+use anyhow::{bail, Result};
+use termion::{color, cursor::HideCursor, event::Key, input::TermRead, raw::IntoRawMode};
+
+use crate::{
+	board::{Board, PlayerAction},
+	util::{Player, Symb},
+};
+
+use super::{MaximizerAgent, MinimizerAgent};
+
+struct SymbolSelector {
+	symbols: Vec<char>,
+	cursor: usize,
+}
+
+impl SymbolSelector {
+	fn new(symbols: Vec<char>) -> Self {
+		Self { symbols, cursor: 0 }
+	}
+
+	fn current(&self) -> char {
+		self.symbols[self.cursor]
+	}
+
+	fn check(&mut self, board: &Board) {
+		while board.contains(Symb::from_char(self.current()).unwrap()) {
+			if self.cursor == 0 {
+				self.cursor = self.symbols.len() - 1;
+			} else {
+				self.cursor -= 1;
+			}
+		}
+	}
+
+	fn up(&mut self, board: &Board) {
+		if self.cursor == 0 {
+			self.cursor = self.symbols.len() - 1;
+		} else {
+			self.cursor -= 1;
+		}
+
+		while board.contains(Symb::from_char(self.current()).unwrap()) {
+			if self.cursor == 0 {
+				self.cursor = self.symbols.len() - 1;
+			} else {
+				self.cursor -= 1;
+			}
+		}
+	}
+
+	fn down(&mut self, board: &Board) {
+		if self.cursor == self.symbols.len() - 1 {
+			self.cursor = 0;
+		} else {
+			self.cursor += 1;
+		}
+
+		while board.contains(Symb::from_char(self.current()).unwrap()) {
+			if self.cursor == self.symbols.len() - 1 {
+				self.cursor = 0;
+			} else {
+				self.cursor += 1;
+			}
+		}
+	}
+}
+
+pub struct PlayerAgent {
+	player: Player,
+	cursor: usize,
+	symbol_selector: SymbolSelector,
+}
+
+impl PlayerAgent {
+	pub fn new(player: Player) -> Self {
+		Self {
+			player,
+			cursor: 0,
+			symbol_selector: SymbolSelector::new(vec![
+				'1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '+', '-', '×', '÷',
+			]),
+		}
+	}
+
+	fn step(&mut self, board: &Board, minimize: bool) -> Result<PlayerAction> {
+		let stdout = HideCursor::from(stdout().into_raw_mode().unwrap());
+		let mut stdout = stdout.lock();
+		let cursor_max = board.size() - 1;
+
+		self.symbol_selector.check(board);
+
+		// Ask for input until we get a valid move
+		'outer: loop {
+			print!(
+				"\r{}{}{}   ╙{}{}{}{}{}╜",
+				// Goal
+				color::Fg(self.player.color()),
+				if minimize { "Min" } else { "Max" },
+				color::Fg(color::Reset),
+				// Cursor
+				" ".repeat(self.cursor),
+				color::Fg(self.player.color()),
+				if board.is_done() {
+					' '
+				} else {
+					self.symbol_selector.current()
+				},
+				color::Fg(color::Reset),
+				" ".repeat(cursor_max - self.cursor),
+			);
+			stdout.flush()?;
+
+			// Player turn
+			let stdin = stdin();
+			for c in stdin.keys() {
+				match c.unwrap() {
+					Key::Char('q') => bail!("player ended game"),
+					Key::Right => {
+						self.cursor = cursor_max.min(self.cursor + 1);
+					}
+					Key::Left => {
+						if self.cursor != 0 {
+							self.cursor -= 1;
+						}
+					}
+					Key::Up => self.symbol_selector.up(board),
+					Key::Down => self.symbol_selector.down(board),
+					Key::Char('\n') => {
+						let symb = Symb::from_char(self.symbol_selector.current());
+						if let Some(symb) = symb {
+							let action = PlayerAction {
+								symb,
+								pos: self.cursor,
+							};
+							if board.can_play(&action) {
+								return Ok(action);
+							}
+						}
+					}
+					Key::Char(c) => {
+						let symb = Symb::from_char(c);
+						if let Some(symb) = symb {
+							let action = PlayerAction {
+								symb,
+								pos: self.cursor,
+							};
+							if board.can_play(&action) {
+								return Ok(action);
+							}
+						}
+					}
+					_ => {}
+				};
+				continue 'outer;
+			}
+		}
+	}
+}
+
+impl MinimizerAgent for PlayerAgent {
+	fn step_min(&mut self, board: &Board) -> Result<PlayerAction> {
+		self.step(board, true)
+	}
+}
+
+impl MaximizerAgent for PlayerAgent {
+	fn step_max(&mut self, board: &Board) -> Result<PlayerAction> {
+		self.step(board, false)
+	}
+}

src/agents/random.rs

@@ -2,6 +2,7 @@ use crate::{
 	board::{Board, PlayerAction},
 	util::Symb,
 };
+use anyhow::Result;
 use rand::Rng;
 use std::num::NonZeroU8;
 
@@ -36,21 +37,21 @@ impl RandomAgent {
 }
 
 impl MinimizerAgent for RandomAgent {
-	fn step_min(&mut self, board: &Board) -> PlayerAction {
+	fn step_min(&mut self, board: &Board) -> Result<PlayerAction> {
 		let mut action = self.random_action(board);
 		while !board.can_play(&action) {
 			action = self.random_action(board);
 		}
-		action
+		Ok(action)
 	}
 }
 
 impl MaximizerAgent for RandomAgent {
-	fn step_max(&mut self, board: &Board) -> PlayerAction {
+	fn step_max(&mut self, board: &Board) -> Result<PlayerAction> {
 		let mut action = self.random_action(board);
 		while !board.can_play(&action) {
 			action = self.random_action(board);
 		}
-		action
+		Ok(action)
 	}
 }

src/board.rs

@@ -170,7 +170,6 @@ impl TreeElement {
 pub struct Board {
 	board: [Option<(Symb, Player)>; 11],
 	free_spots: usize,
-	current_player: Player,
 }
 
 impl Display for Board {
@@ -195,11 +194,10 @@ impl Display for Board {
 
 #[allow(dead_code)]
 impl Board {
-	pub fn new(current_player: Player) -> Self {
+	pub fn new() -> Self {
 		Self {
 			free_spots: 11,
 			board: Default::default(),
-			current_player,
 		}
 	}
 
@@ -211,10 +209,6 @@ impl Board {
 		self.board.get(idx)
 	}
 
-	pub fn current_player(&self) -> Player {
-		self.current_player
-	}
-
 	pub fn is_done(&self) -> bool {
 		self.free_spots == 0
 	}
@@ -295,13 +289,12 @@ impl Board {
 
 	/// Place the marked symbol at the given position.
 	/// Returns true for valid moves and false otherwise.
-	pub fn play(&mut self, action: PlayerAction) -> bool {
+	pub fn play(&mut self, action: PlayerAction, player: Player) -> bool {
 		if !self.can_play(&action) {
 			return false;
 		}
 
-		self.board[action.pos] = Some((action.symb, self.current_player));
-		self.current_player.invert();
+		self.board[action.pos] = Some((action.symb, player));
 		self.free_spots -= 1;
 		true
 	}
@@ -489,7 +482,7 @@ impl Board {
 			.filter_map(|c| {
 				if c == '_' {
 					Some(None)
-				} else if let Some(symb) = Symb::from_char(&c) {
+				} else if let Some(symb) = Symb::from_char(c) {
 					Some(Some((symb, current_player)))
 				} else {
 					None
@@ -510,10 +503,6 @@ impl Board {
 			}
 		}
 
-		Some(Self {
-			board,
-			free_spots,
-			current_player,
-		})
+		Some(Self { board, free_spots })
 	}
 }

src/main.rs

@@ -1,12 +1,5 @@
-use anyhow::Result;
-use std::io::{stdin, stdout, StdoutLock, Write};
-use termion::{
-	color::{self},
-	cursor::HideCursor,
-	event::Key,
-	input::TermRead,
-	raw::IntoRawMode,
-};
+use anyhow::{bail, Result};
+use termion::color::{self};
 
 mod agents;
 mod board;
@@ -14,172 +7,55 @@ mod util;
 use board::Board;
 use util::{Player, Symb};
 
-use crate::board::PlayerAction;
-
 fn play(
-	stdout: &mut StdoutLock,
-	player_max: bool,
-	computer: &mut dyn agents::MinimizerAgent,
+	maxi: &mut dyn agents::MaximizerAgent,
+	mini: &mut dyn agents::MinimizerAgent,
 ) -> Result<Board> {
-	let mut cursor = 0usize;
-	let cursor_offset = 10usize - 1;
-	let cursor_max = 10usize;
+	let mut board = Board::new();
+	let mut is_first_turn = true;
+	let mut is_maxi_turn = true;
 
-	let mut board = Board::new(if player_max {
-		Player::Human
-	} else {
-		Player::Computer
-	});
-
-	let mut is_first = true;
-	let mut print_board = true;
-
-	// For human player UI
-	let symbols = [
-		'1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '+', '-', '×', '÷',
-	];
-	let mut selected_symbol = 0;
-
-	'outer: loop {
-		// Computer turn
-		if board.current_player() == Player::Computer && !board.is_done() {
-			computer.step_min(&mut board);
-		}
-
-		let min_color = if !player_max {
-			Player::Human.color()
-		} else {
-			Player::Computer.color()
-		};
-
-		let max_color = if player_max {
-			Player::Human.color()
-		} else {
-			Player::Computer.color()
-		};
-
-		if print_board {
-			println!(
-				"\r{}\r{}Min{}/{}Max{}  {}{}{}",
-				" ".repeat(cursor_max + cursor_offset),
-				color::Fg(min_color),
-				color::Fg(color::Reset),
-				color::Fg(max_color),
-				color::Fg(color::Reset),
-				if is_first { '╓' } else { '║' },
-				board,
-				if is_first { '╖' } else { '║' },
-			);
-			is_first = false;
-		}
-
-		while board.contains(Symb::from_char(&symbols[selected_symbol]).unwrap()) {
-			if selected_symbol == symbols.len() - 1 {
-				selected_symbol = 0;
-			} else {
-				selected_symbol += 1;
-			}
-		}
-
-		print!(
-			"\r{}╙{}{}{}{}{}╜",
-			" ".repeat(cursor_offset),
-			" ".repeat(cursor),
-			color::Fg(board.current_player().color()),
-			if board.is_done() {
-				' '
-			} else {
-				symbols[selected_symbol]
-			},
-			color::Fg(color::Reset),
-			" ".repeat(cursor_max - cursor),
+	while !board.is_done() {
+		// Print board
+		println!(
+			"\r{}{}{}{}",
+			" ".repeat(6),
+			if is_first_turn { '╓' } else { '║' },
+			board,
+			if is_first_turn { '╖' } else { '║' },
 		);
-		stdout.flush()?;
+		is_first_turn = false;
 
-		if board.is_done() {
-			break;
-		}
+		// Take action
+		let action = if is_maxi_turn {
+			maxi.step_max(&board)?
+		} else {
+			mini.step_min(&board)?
+		};
+		is_maxi_turn = !is_maxi_turn;
 
-		// Player turn
-		let stdin = stdin();
-		for c in stdin.keys() {
-			print_board = match c.unwrap() {
-				Key::Char('q') => break 'outer,
-				Key::Right => {
-					cursor = cursor_max.min(cursor + 1);
-					false
-				}
-				Key::Left => {
-					if cursor != 0 {
-						cursor -= 1
-					}
-					false
-				}
-				Key::Up => {
-					if selected_symbol == 0 {
-						selected_symbol = symbols.len() - 1;
-					} else {
-						selected_symbol -= 1;
-					}
-
-					while board.contains(Symb::from_char(&symbols[selected_symbol]).unwrap()) {
-						if selected_symbol == 0 {
-							selected_symbol = symbols.len() - 1;
-						} else {
-							selected_symbol -= 1;
-						}
-					}
-					false
-				}
-				Key::Down => {
-					if selected_symbol == symbols.len() - 1 {
-						selected_symbol = 0;
-					} else {
-						selected_symbol += 1;
-					}
-
-					while board.contains(Symb::from_char(&symbols[selected_symbol]).unwrap()) {
-						if selected_symbol == symbols.len() - 1 {
-							selected_symbol = 0;
-						} else {
-							selected_symbol += 1;
-						}
-					}
-					false
-				}
-				Key::Char('\n') => {
-					let symb = Symb::from_char(&symbols[selected_symbol]);
-					if let Some(symb) = symb {
-						let action = PlayerAction { symb, pos: cursor };
-						board.play(action)
-					} else {
-						false
-					}
-				}
-				Key::Char(c) => {
-					let symb = Symb::from_char(&c);
-					if let Some(symb) = symb {
-						let action = PlayerAction { symb, pos: cursor };
-						board.play(action)
-					} else {
-						false
-					}
-				}
-				_ => false,
-			};
-			continue 'outer;
+		if !board.play(
+			action,
+			if is_maxi_turn {
+				Player::Human
+			} else {
+				Player::Computer
+			},
+		) {
+			bail!("agent made invalid move")
 		}
 	}
 
-	return Ok(board);
+	println!("\r{}║{}║", " ".repeat(6), board,);
+	println!("\r{}╙{}╜", " ".repeat(6), " ".repeat(board.size()));
+	Ok(board)
 }
 
 fn main() -> Result<()> {
-	let stdout = HideCursor::from(stdout().into_raw_mode().unwrap());
-	let mut stdout = stdout.lock();
+	let mut maxi = agents::PlayerAgent::new(Player::Human);
+	let mut mini = agents::MinMaxTree {};
 
-	let mut agent = agents::DiffuseAgent {};
-	let a = play(&mut stdout, true, &mut agent)?;
+	let a = play(&mut maxi, &mut mini)?;
 	if a.is_done() {
 		println!(
 			"\r\n{}Your score:{} {:.2}\n\n",
@@ -195,24 +71,5 @@ fn main() -> Result<()> {
 		);
 		return Ok(());
 	}
-
-	let mut agent = agents::RandomAgent {};
-	let b = play(&mut stdout, false, &mut agent)?;
-	if b.is_done() {
-		println!(
-			"\r\n{}Computer score:{} {:.2}\n\n",
-			color::Fg(Player::Computer.color()),
-			color::Fg(color::Reset),
-			b.evaluate().unwrap()
-		);
-	} else {
-		println!(
-			"\r\n{}Quitting{}\r\n",
-			color::Fg(color::Red),
-			color::Fg(color::Reset),
-		);
-		return Ok(());
-	}
-
 	Ok(())
 }

src/util.rs

@@ -12,13 +12,6 @@ pub enum Player {
 }
 
 impl Player {
-	pub fn invert(&mut self) {
-		match self {
-			Self::Human => *self = Self::Computer,
-			Self::Computer => *self = Self::Human,
-		}
-	}
-
 	pub fn color(&self) -> &dyn Color {
 		match self {
 			Player::Computer => &color::LightBlack,
@@ -79,7 +72,7 @@ impl Symb {
 		self == &Self::Minus
 	}
 
-	pub fn from_char(c: &char) -> Option<Self> {
+	pub fn from_char(c: char) -> Option<Self> {
 		match c {
 			'1' => Some(Self::Number(NonZeroU8::new(1).unwrap())),
 			'2' => Some(Self::Number(NonZeroU8::new(2).unwrap())),