improvements to strategies API

make strategies its own module
use trait objects so you can mix and match strategies
stop using internal state associated type..

src/main.rs

@@ -3,7 +3,10 @@ extern crate rand;
 extern crate log;
 
 mod game;
-mod strategies;
+mod simulator;
+mod strategies {
+    pub mod examples;
+}
 mod info;
 
 #[allow(unused_imports)]
@@ -35,7 +38,23 @@ fn main() {
         num_lives: 3,
     };
     let n = 1;
-    // strategies::simulate(&opts, &strategies::AlwaysDiscard, n);
-    // strategies::simulate(&opts, &strategies::AlwaysPlay, n);
-    strategies::simulate(&opts, &strategies::RandomStrategy, n);
+    // simulator::simulate(&opts, &strategies::examples::AlwaysDiscard, n);
+    // simulator::simulate_symmetric(&opts, strategies::examples::AlwaysPlayConfig, n);
+    // simulator::simulate(
+    //     &opts,
+    //     &vec![
+    //         Box::new(strategies::examples::AlwaysPlayConfig),
+    //         Box::new(strategies::examples::AlwaysPlayConfig),
+    //         Box::new(strategies::examples::AlwaysPlayConfig),
+    //         Box::new(strategies::examples::AlwaysPlayConfig),
+    //     ],
+    //     n);
+    simulator::simulate_symmetric(
+        &opts,
+        strategies::examples::RandomStrategyConfig {
+            hint_probability: 0.4,
+            play_probability: 0.2,
+        },
+        n
+    );
 }

src/simulator.rs

@@ -0,0 +1,73 @@
+use game::*;
+use std::collections::HashMap;
+
+// Trait to implement for any valid Hanabi strategy
+// State management is done by the simulator, to avoid cheating
+pub trait Strategy {
+    fn decide(&mut self, &Player, &GameStateView) -> TurnChoice;
+    fn update(&mut self, &Turn, &GameStateView);
+}
+pub trait StrategyConfig {
+    fn initialize(&self, &Player, &GameStateView) -> Box<Strategy>;
+}
+
+pub fn simulate_once<'a>(opts: &GameOptions, strat_configs: &Vec<Box<StrategyConfig + 'a>>) -> Score {
+    let mut game = GameState::new(opts);
+
+    assert_eq!(opts.num_players, (strat_configs.len() as u32));
+
+    let mut strategies : HashMap<Player, Box<Strategy>> = HashMap::new();
+    let mut i = 0;
+    for player in game.get_players() {
+        strategies.insert(
+            player,
+            (*strat_configs[i]).initialize(&player, &game.get_view(player)),
+        );
+        i += 1;
+    }
+
+    while !game.is_over() {
+        debug!("Turn {}", game.board.turn);
+        let player = game.board.player;
+        let choice = {
+            let mut strategy = strategies.get_mut(&player).unwrap();
+            strategy.decide(&player, &game.get_view(player))
+        };
+
+        game.process_choice(&choice);
+
+        let turn = Turn {
+            player: &player,
+            choice: &choice,
+        };
+
+        for player in game.get_players() {
+            let mut strategy = strategies.get_mut(&player).unwrap();
+            strategy.update(&turn, &game.get_view(player));
+        }
+
+        // TODO: do some stuff
+        debug!("State:\n{}", game);
+    }
+    game.score()
+}
+
+pub fn simulate<'a>(opts: &GameOptions, strat_configs: &Vec<Box<StrategyConfig + 'a>>, n_trials: u32) -> f32 {
+    let mut total_score = 0;
+    for _ in 0..n_trials {
+        let score = simulate_once(&opts, strat_configs);
+        info!("Scored: {:?}", score);
+        total_score += score;
+    }
+    let average: f32 = (total_score as f32) / (n_trials as f32);
+    info!("Average score: {:?}", average);
+    average
+}
+
+pub fn simulate_symmetric<'a, S: StrategyConfig + Clone + 'a>(opts: &GameOptions, strat_config: S, n_trials: u32) -> f32 {
+    let mut strat_configs = Vec::new();
+    for _ in 0..opts.num_players {
+        strat_configs.push(Box::new(strat_config.clone()) as Box<StrategyConfig + 'a>);
+    }
+    simulate(opts, &strat_configs, n_trials)
+}

src/strategies.rs

@@ -1,129 +0,0 @@
-use game::*;
-use std::collections::HashMap;
-use rand::{self, Rng};
-
-// Trait to implement for any valid Hanabi strategy
-// State management is done by the simulator, to avoid cheating
-pub trait Strategy {
-    type InternalState;
-    fn initialize(&Player, &GameStateView) -> Self::InternalState;
-    fn decide(&mut Self::InternalState, &Player, &GameStateView) -> TurnChoice;
-    fn update(&mut Self::InternalState, &Turn, &GameStateView);
-}
-
-pub fn simulate_once<S: Strategy>(opts: &GameOptions, _: &S) -> Score {
-    let mut game = GameState::new(opts);
-
-    let mut internal_states : HashMap<Player, S::InternalState> = HashMap::new();
-    for player in game.get_players() {
-        internal_states.insert(
-            player,
-            S::initialize(&player, &game.get_view(player)),
-        );
-    }
-
-    while !game.is_over() {
-        debug!("Turn {}", game.board.turn);
-        let player = game.board.player;
-        let choice = {
-            let ref mut internal_state = internal_states.get_mut(&player).unwrap();
-            S::decide(internal_state, &player, &game.get_view(player))
-        };
-
-        game.process_choice(&choice);
-
-        let turn = Turn {
-            player: &player,
-            choice: &choice,
-        };
-
-        for player in game.get_players() {
-            let ref mut internal_state = internal_states.get_mut(&player).unwrap();
-
-            S::update(internal_state, &turn, &game.get_view(player));
-        }
-
-        // TODO: do some stuff
-        debug!("State:\n{}", game);
-    }
-    game.score()
-}
-
-pub fn simulate<S: Strategy>(opts: &GameOptions, strategy: &S, n_trials: u32) -> f32 {
-    let mut total_score = 0;
-    for _ in 0..n_trials {
-        let score = simulate_once(&opts, strategy);
-        info!("Scored: {:?}", score);
-        total_score += score;
-    }
-    let average: f32 = (total_score as f32) / (n_trials as f32);
-    info!("Average score: {:?}", average);
-    average
-}
-
-// dummy, terrible strategy
-#[allow(dead_code)]
-pub struct AlwaysPlay;
-impl Strategy for AlwaysPlay {
-    type InternalState = ();
-    fn initialize(_: &Player, _: &GameStateView) -> () {
-        ()
-    }
-    fn decide(_: &mut (), _: &Player, _: &GameStateView) -> TurnChoice {
-        TurnChoice::Play(0)
-    }
-    fn update(_: &mut (), _: &Turn, _: &GameStateView) {
-    }
-}
-
-// dummy, terrible strategy
-#[allow(dead_code)]
-pub struct AlwaysDiscard;
-impl Strategy for AlwaysDiscard {
-    type InternalState = ();
-    fn initialize(_: &Player, _: &GameStateView) -> () {
-        ()
-    }
-    fn decide(_: &mut (), _: &Player, _: &GameStateView) -> TurnChoice {
-        TurnChoice::Discard(0)
-    }
-    fn update(_: &mut (), _: &Turn, _: &GameStateView) {
-    }
-}
-
-// dummy, terrible strategy
-#[allow(dead_code)]
-pub struct RandomStrategy;
-impl Strategy for RandomStrategy {
-    type InternalState = ();
-    fn initialize(_: &Player, _: &GameStateView) -> () {
-        ()
-    }
-    fn decide(_: &mut (), me: &Player, view: &GameStateView) -> TurnChoice {
-        let p = rand::random::<f64>();
-        if p < 0.4 {
-            if view.board.hints_remaining > 0 {
-                let hinted = {
-                    if rand::random() {
-                        // hint a color
-                        Hinted::Color(rand::thread_rng().choose(&COLORS).unwrap())
-                    } else {
-                        Hinted::Value(*rand::thread_rng().choose(&VALUES).unwrap())
-                    }
-                };
-                TurnChoice::Hint(Hint {
-                    player: view.board.player_to_left(&me),
-                    hinted: hinted,
-                })
-            } else {
-                TurnChoice::Discard(0)
-            }
-        } else if p < 0.8 {
-            TurnChoice::Discard(0)
-        } else {
-            TurnChoice::Play(0)
-        }
-    }
-    fn update(_: &mut (), _: &Turn, _: &GameStateView) {
-    }
-}

src/strategies/examples.rs

@@ -0,0 +1,91 @@
+use simulator::*;
+use game::*;
+use rand::{self, Rng};
+
+// dummy, terrible strategy
+#[allow(dead_code)]
+#[derive(Clone)]
+pub struct AlwaysPlayConfig;
+impl StrategyConfig for AlwaysPlayConfig {
+    fn initialize(&self, _: &Player, _: &GameStateView) -> Box<Strategy> {
+        Box::new(AlwaysPlay)
+    }
+}
+pub struct AlwaysPlay;
+impl Strategy for AlwaysPlay {
+    fn decide(&mut self, _: &Player, _: &GameStateView) -> TurnChoice {
+        TurnChoice::Play(0)
+    }
+    fn update(&mut self, _: &Turn, _: &GameStateView) {
+    }
+}
+
+// dummy, terrible strategy
+#[allow(dead_code)]
+#[derive(Clone)]
+pub struct AlwaysDiscardConfig;
+impl StrategyConfig for AlwaysDiscardConfig {
+    fn initialize(&self, _: &Player, _: &GameStateView) -> Box<Strategy> {
+        Box::new(AlwaysDiscard)
+    }
+}
+pub struct AlwaysDiscard;
+impl Strategy for AlwaysDiscard {
+    fn decide(&mut self, _: &Player, _: &GameStateView) -> TurnChoice {
+        TurnChoice::Discard(0)
+    }
+    fn update(&mut self, _: &Turn, _: &GameStateView) {
+    }
+}
+
+
+// dummy, terrible strategy
+#[allow(dead_code)]
+#[derive(Clone)]
+pub struct RandomStrategyConfig {
+    pub hint_probability: f64,
+    pub play_probability: f64,
+}
+
+impl StrategyConfig for RandomStrategyConfig {
+    fn initialize(&self, _: &Player, _: &GameStateView) -> Box<Strategy> {
+        Box::new(RandomStrategy {
+            hint_probability: self.hint_probability,
+            play_probability: self.play_probability,
+        })
+    }
+}
+pub struct RandomStrategy {
+    pub hint_probability: f64,
+    pub play_probability: f64,
+}
+
+impl Strategy for RandomStrategy {
+    fn decide(&mut self, me: &Player, view: &GameStateView) -> TurnChoice {
+        let p = rand::random::<f64>();
+        if p < self.hint_probability {
+            if view.board.hints_remaining > 0 {
+                let hinted = {
+                    if rand::random() {
+                        // hint a color
+                        Hinted::Color(rand::thread_rng().choose(&COLORS).unwrap())
+                    } else {
+                        Hinted::Value(*rand::thread_rng().choose(&VALUES).unwrap())
+                    }
+                };
+                TurnChoice::Hint(Hint {
+                    player: view.board.player_to_left(&me),
+                    hinted: hinted,
+                })
+            } else {
+                TurnChoice::Discard(0)
+            }
+        } else if p < self.hint_probability + self.play_probability {
+            TurnChoice::Play(0)
+        } else {
+            TurnChoice::Discard(0)
+        }
+    }
+    fn update(&mut self, _: &Turn, _: &GameStateView) {
+    }
+}