possible_instructions

src/card_game.rs

@@ -86,7 +86,7 @@ impl Card {
 	}
 }
 
-#[derive(Hash)]
+#[derive(Clone, Debug, Hash)]
 pub struct Stack(Vec<Card>);
 impl Stack {
 	pub fn new() -> Self {
@@ -120,7 +120,7 @@ impl std::ops::DerefMut for Stack {
 	}
 }
 
-#[derive(Hash)]
+#[derive(Clone, Debug, Hash)]
 pub struct Pile {
 	face_down: Stack,
 	face_up: Stack,

src/klondike.rs

@@ -7,12 +7,9 @@ impl Default for KlondikeConfig {
 		KlondikeConfig {}
 	}
 }
-#[derive(Hash)]
-struct KlondikeState {
-	piles: [Pile; 13],
-}
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 pub enum KlondikePileId {
+	Stock,
 	Tableau0,
 	Tableau1,
 	Tableau2,
@@ -21,71 +18,64 @@ pub enum KlondikePileId {
 	Tableau5,
 	Tableau6,
 	Tableau7,
-	Stock,
 	Foundation0,
 	Foundation1,
 	Foundation2,
 	Foundation3,
 }
+impl KlondikePileId {
+	fn next(self) -> Option<Self> {
+		use KlondikePileId::*;
+		Some(match self {
+			Stock => Tableau0,
+			Tableau0 => Tableau1,
+			Tableau1 => Tableau2,
+			Tableau2 => Tableau3,
+			Tableau3 => Tableau4,
+			Tableau4 => Tableau5,
+			Tableau5 => Tableau6,
+			Tableau6 => Tableau7,
+			Tableau7 => Foundation0,
+			Foundation0 => Foundation1,
+			Foundation1 => Foundation2,
+			Foundation2 => Foundation3,
+			Foundation3 => return None,
+		})
+	}
+}
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 pub struct KlondikeInstruction {
 	pub src: KlondikePileId,
 	pub dst: KlondikePileId,
 }
-pub struct Klondike {
-	config: KlondikeConfig,
-	state: KlondikeState,
-}
-impl Klondike {
-	pub fn new(mut seed: Rng, config: KlondikeConfig) -> Self {
-		// shuffle a new deck
-		let mut deck = Stack::full_deck(0);
-		use rand::seq::SliceRandom;
-		deck.shuffle(&mut seed);
-
-		// generate tableaus
-		let [t0, t1, t2, t3, t4, t5, t6, t7] = core::array::from_fn(|i| {
-			let stack = deck.split_off(i).into();
-			let mut pile = Pile::new_face_down(stack);
-			pile.push(deck.pop().unwrap());
-			pile
-		});
-
-		// stock is remaining cards
-		let stock = Pile::new_face_down(deck);
-
-		let state = KlondikeState {
-			piles: [
-				t0,
-				t1,
-				t2,
-				t3,
-				t4,
-				t5,
-				t6,
-				t7,
-				stock,
-				Pile::new(),
-				Pile::new(),
-				Pile::new(),
-				Pile::new(),
-			],
-		};
-		Self { config, state }
+impl KlondikeInstruction {
+	fn next(self) -> Option<Self> {
+		let KlondikeInstruction { src, dst } = self;
+		if let Some(next_dst) = dst.next() {
+			return Some(Self { src, dst: next_dst });
+		}
+		if let Some(next_src) = src.next() {
+			return Some(Self {
+				src: next_src,
+				dst: KlondikePileId::Stock,
+			});
+		}
+		None
 	}
-	pub fn pile(&self, index: KlondikePileId) -> &Pile {
-		&self.state.piles[index as usize]
+}
+
+#[derive(Clone, Hash)]
+struct KlondikeState {
+	piles: [Pile; 13],
+}
+impl KlondikeState {
+	fn pile(&self, index: KlondikePileId) -> &Pile {
+		&self.piles[index as usize]
 	}
 	fn pile_mut(&mut self, index: KlondikePileId) -> &mut Pile {
-		&mut self.state.piles[index as usize]
+		&mut self.piles[index as usize]
 	}
-}
-impl Game for Klondike {
-	type Instruction = KlondikeInstruction;
-	fn possible_instructions(&self) -> impl Iterator<Item = Self::Instruction> + use<> {
-		vec![].into_iter()
-	}
-	fn validate_instruction(&self, instruction: Self::Instruction) -> bool {
+	fn validate_instruction(&self, instruction: KlondikeInstruction) -> bool {
 		match instruction {
 			// Stock -> Stock draws a card or resets the stock
 			KlondikeInstruction {
@@ -142,6 +132,87 @@ impl Game for Klondike {
 			}
 		}
 	}
+}
+
+pub struct Klondike {
+	config: KlondikeConfig,
+	state: KlondikeState,
+}
+impl Klondike {
+	pub fn new(mut seed: Rng, config: KlondikeConfig) -> Self {
+		// shuffle a new deck
+		let mut deck = Stack::full_deck(0);
+		use rand::seq::SliceRandom;
+		deck.shuffle(&mut seed);
+
+		// generate tableaus
+		let [t0, t1, t2, t3, t4, t5, t6, t7] = core::array::from_fn(|i| {
+			let stack = deck.split_off(i).into();
+			let mut pile = Pile::new_face_down(stack);
+			pile.push(deck.pop().unwrap());
+			pile
+		});
+
+		// stock is remaining cards
+		let stock = Pile::new_face_down(deck);
+
+		let state = KlondikeState {
+			piles: [
+				t0,
+				t1,
+				t2,
+				t3,
+				t4,
+				t5,
+				t6,
+				t7,
+				stock,
+				Pile::new(),
+				Pile::new(),
+				Pile::new(),
+				Pile::new(),
+			],
+		};
+		Self { config, state }
+	}
+	#[inline]
+	pub fn pile(&self, index: KlondikePileId) -> &Pile {
+		self.state.pile(index)
+	}
+	#[inline]
+	fn pile_mut(&mut self, index: KlondikePileId) -> &mut Pile {
+		self.state.pile_mut(index)
+	}
+}
+pub struct KlondikeIter {
+	instruction: Option<KlondikeInstruction>,
+}
+impl KlondikeIter {
+	fn new() -> Self {
+		Self {
+			instruction: Some(KlondikeInstruction {
+				src: KlondikePileId::Stock,
+				dst: KlondikePileId::Stock,
+			}),
+		}
+	}
+}
+impl Iterator for KlondikeIter {
+	type Item = KlondikeInstruction;
+	fn next(&mut self) -> Option<Self::Item> {
+		self.instruction = self.instruction?.next();
+		self.instruction
+	}
+}
+impl Game for Klondike {
+	type Instruction = KlondikeInstruction;
+	fn possible_instructions(&self) -> impl Iterator<Item = Self::Instruction> + use<> {
+		let state = self.state.clone();
+		KlondikeIter::new().filter(move |&instruction| state.validate_instruction(instruction))
+	}
+	fn validate_instruction(&self, instruction: Self::Instruction) -> bool {
+		self.state.validate_instruction(instruction)
+	}
 	fn process_instruction(&mut self, instruction: Self::Instruction) {
 		let card = self.pile_mut(instruction.src).pop().unwrap();
 		self.pile_mut(instruction.dst).push(card);