klondike v0.4.0 tweaks + serde

Closes #15

Reviewed-on: #16
Co-authored-by: Rhys Lloyd <krakow20@gmail.com>
Co-committed-by: Rhys Lloyd <krakow20@gmail.com>

Cargo.lock

@@ -11,8 +11,14 @@ checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
 [[package]]
 name = "arrayvec"
 version = "0.7.6"
+source = "sparse+https://git.aleshym.co/api/packages/Quaternions/cargo/"
+checksum = "813440870d646c57c222c1d713dc4e3ddcb2919c3801564d767d85d7bf2afee4"
+
+[[package]]
+name = "autocfg"
+version = "1.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
+checksum = "f2032f911046de80f0a198e0901378627c33f59ea0ac00e363d481118bd70a53"
 
 [[package]]
 name = "bitflags"
@@ -22,9 +28,11 @@ checksum = "c4512299f36f043ab09a583e57bceb5a5aab7a73db1805848e8fef3c9e8c78b3"
 
 [[package]]
 name = "card_game"
-version = "0.2.0"
+version = "0.4.1"
 dependencies = [
  "arrayvec",
+ "serde",
+ "serde_derive",
 ]
 
 [[package]]
@@ -44,6 +52,17 @@ dependencies = [
  "rand_core",
 ]
 
+[[package]]
+name = "console"
+version = "0.16.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d64e8af5551369d19cf50138de61f1c42074ab970f74e99be916646777f8fc87"
+dependencies = [
+ "encode_unicode",
+ "libc",
+ "windows-sys",
+]
+
 [[package]]
 name = "cpufeatures"
 version = "0.3.0"
@@ -53,12 +72,34 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "encode_unicode"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34aa73646ffb006b8f5147f3dc182bd4bcb190227ce861fc4a4844bf8e3cb2c0"
+
 [[package]]
 name = "equivalent"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
 
+[[package]]
+name = "errno"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
+dependencies = [
+ "libc",
+ "windows-sys",
+]
+
+[[package]]
+name = "fastrand"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9f1f227452a390804cdb637b74a86990f2a7d7ba4b7d5693aac9b4dd6defd8d6"
+
 [[package]]
 name = "foldhash"
 version = "0.1.5"
@@ -118,6 +159,18 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "insta"
+version = "1.47.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b4a6248eb93a4401ed2f37dfe8ea592d3cf05b7cf4f8efa867b6895af7e094e"
+dependencies = [
+ "console",
+ "once_cell",
+ "similar",
+ "tempfile",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.18"
@@ -126,10 +179,15 @@ checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"
 
 [[package]]
 name = "klondike"
-version = "0.1.0"
+version = "0.4.0"
 dependencies = [
  "card_game",
+ "insta",
  "rand",
+ "rmp-serde",
+ "serde",
+ "serde_derive",
+ "serde_json",
 ]
 
 [[package]]
@@ -162,6 +220,12 @@ version = "0.2.186"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "68ab91017fe16c622486840e4c83c9a37afeff978bd239b5293d61ece587de66"
 
+[[package]]
+name = "linux-raw-sys"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a66949e030da00e8c7d4434b251670a91556f4144941d37452769c25d58a53"
+
 [[package]]
 name = "log"
 version = "0.4.29"
@@ -174,6 +238,21 @@ version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 
+[[package]]
+name = "num-traits"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "once_cell"
+version = "1.21.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9f7c3e4beb33f85d45ae3e3a1792185706c8e16d043238c593331cc7cd313b50"
+
 [[package]]
 name = "prettyplease"
 version = "0.2.37"
@@ -225,6 +304,38 @@ version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "63b8176103e19a2643978565ca18b50549f6101881c443590420e4dc998a3c69"
 
+[[package]]
+name = "rmp"
+version = "0.8.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ba8be72d372b2c9b35542551678538b562e7cf86c3315773cae48dfbfe7790c"
+dependencies = [
+ "num-traits",
+]
+
+[[package]]
+name = "rmp-serde"
+version = "1.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72f81bee8c8ef9b577d1681a70ebbc962c232461e397b22c208c43c04b67a155"
+dependencies = [
+ "rmp",
+ "serde",
+]
+
+[[package]]
+name = "rustix"
+version = "1.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6fe4565b9518b83ef4f91bb47ce29620ca828bd32cb7e408f0062e9930ba190"
+dependencies = [
+ "bitflags",
+ "errno",
+ "libc",
+ "linux-raw-sys",
+ "windows-sys",
+]
+
 [[package]]
 name = "semver"
 version = "1.0.28"
@@ -273,6 +384,12 @@ dependencies = [
  "zmij",
 ]
 
+[[package]]
+name = "similar"
+version = "2.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbbb5d9659141646ae647b42fe094daf6c6192d1620870b449d9557f748b2daa"
+
 [[package]]
 name = "syn"
 version = "2.0.117"
@@ -284,6 +401,19 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "tempfile"
+version = "3.27.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32497e9a4c7b38532efcdebeef879707aa9f794296a4f0244f6f69e9bc8574bd"
+dependencies = [
+ "fastrand",
+ "getrandom",
+ "once_cell",
+ "rustix",
+ "windows-sys",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.24"
@@ -348,6 +478,21 @@ dependencies = [
  "semver",
 ]
 
+[[package]]
+name = "windows-link"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
+
+[[package]]
+name = "windows-sys"
+version = "0.61.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
+dependencies = [
+ "windows-link",
+]
+
 [[package]]
 name = "wit-bindgen"
 version = "0.51.0"

Cargo.toml

@@ -8,8 +8,8 @@ members = [
 resolver = "3"
 
 [workspace.dependencies]
-card_game = { version = "0.2.0", path = "card_game", registry = "Quaternions" }
-klondike = { version = "0.1.0", path = "klondike", registry = "Quaternions" }
+card_game = { version = "0.4.1", path = "card_game", registry = "Quaternions" }
+klondike = { version = "0.4.0", path = "klondike", registry = "Quaternions" }
 
 [workspace.lints.rust]
 # unsafe_code = "forbid"

README.md

@@ -0,0 +1 @@
+card_game/README.md

card_game/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "card_game"
-version = "0.2.0"
+version = "0.4.1"
 edition = "2024"
 repository = "https://git.aleshym.co/Quaternions/card_game"
 license = "MIT OR Apache-2.0"
@@ -9,7 +9,13 @@ authors = ["Rhys Lloyd <krakow20@gmail.com>"]
 keywords = ["card", "cards", "solitaire", "klondike"]
 
 [dependencies]
-arrayvec = "0.7.6"
+arrayvec = { version = "0.7.6", registry = "Quaternions", features = ["len_u8"], default-features = false }
+serde = { version = "1.0.228", default-features = false, optional = true }
+serde_derive = { version = "1.0.228", default-features = false, optional = true }
 
 [lints]
 workspace = true
+
+[features]
+default = ["serde"]
+serde = ["dep:serde", "dep:serde_derive"]

card_game/src/lib.rs

@@ -6,11 +6,16 @@ struct ReadmeDoctests;
 use core::ops::RangeBounds;
 
 // TODO: pub struct ValidInstruction<I>(I);
-pub trait Game {
-	type Stats;
-	type Config;
-	type Instruction;
-	fn possible_instructions(&self) -> impl Iterator<Item = Self::Instruction> + use<Self>;
+pub trait Game: Clone {
+	type Score: Clone + core::fmt::Debug;
+	type Stats: Clone + core::fmt::Debug;
+	type Config: Clone + core::fmt::Debug;
+	type Instruction: Clone + core::fmt::Debug;
+	fn score(&self, stats: &Self::Stats, config: &Self::Config) -> Self::Score;
+	fn possible_instructions(
+		&self,
+		config: &Self::Config,
+	) -> impl Iterator<Item = Self::Instruction> + use<Self>;
 	fn is_instruction_valid(&self, config: &Self::Config, instruction: Self::Instruction) -> bool;
 	fn process_instruction(
 		&mut self,
@@ -141,6 +146,11 @@ impl Rank {
 /// 2 bits for suit ID
 /// 4 bits for card Value
 #[derive(Clone, Debug, Eq, Hash, PartialEq)]
+#[cfg_attr(
+	feature = "serde",
+	derive(serde_derive::Deserialize, serde_derive::Serialize),
+	serde(transparent)
+)]
 pub struct Card(core::num::NonZeroU8);
 impl Card {
 	pub const fn new(deck: Deck, suit: Suit, rank: Rank) -> Self {
@@ -225,8 +235,54 @@ impl<const CAP: usize> IntoIterator for Stack<CAP> {
 	}
 }
 
+#[cfg(feature = "serde")]
+impl<'de, const CAP: usize> serde::Deserialize<'de> for Stack<CAP> {
+	fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+	where
+		D: serde::Deserializer<'de>,
+	{
+		struct StackVisitor<const CAP: usize>;
+		impl<'de, const CAP: usize> serde::de::Visitor<'de> for StackVisitor<CAP> {
+			type Value = Stack<CAP>;
+			fn expecting(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+				write!(f, "Card Stack")
+			}
+			fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+			where
+				A: serde::de::SeqAccess<'de>,
+			{
+				use serde::de::Error;
+				let mut stack = Stack::new();
+				while let Some(card) = seq.next_element()? {
+					stack.try_push(card).map_err(A::Error::custom)?;
+				}
+				Ok(stack)
+			}
+		}
+		deserializer.deserialize_seq(StackVisitor)
+	}
+}
+#[cfg(feature = "serde")]
+impl<const CAP: usize> serde::Serialize for Stack<CAP> {
+	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+	where
+		S: serde::Serializer,
+	{
+		use serde::ser::SerializeSeq;
+		let mut seq = serializer.serialize_seq(Some(self.len()))?;
+		for card in self.as_slice() {
+			seq.serialize_element(card)?;
+		}
+		seq.end()
+	}
+}
+
 /// A pile is a stack of face down cards and a stack of face up cards.
 #[derive(Clone, Debug, Default, Eq, Hash, PartialEq)]
+#[cfg_attr(
+	feature = "serde",
+	derive(serde_derive::Deserialize, serde_derive::Serialize)
+)]
 pub struct Pile<const DN: usize, const UP: usize> {
 	face_down: Stack<DN>,
 	face_up: Stack<UP>,
@@ -244,10 +300,13 @@ impl<const DN: usize, const UP: usize> Pile<DN, UP> {
 			face_up: Stack::new(),
 		}
 	}
-	pub fn flip_up(&mut self) {
+	/// Returns whether a card was flipped up.
+	pub fn flip_up(&mut self) -> bool {
 		if let Some(card) = self.face_down.pop() {
 			self.face_up.push(card);
+			return true;
 		}
+		false
 	}
 	pub fn is_empty(&self) -> bool {
 		self.face_down.is_empty() && self.face_up.is_empty()
@@ -255,25 +314,31 @@ impl<const DN: usize, const UP: usize> Pile<DN, UP> {
 	pub fn pop(&mut self) -> Option<Card> {
 		self.face_up.pop()
 	}
-	pub fn pop_flip_up(&mut self) -> Option<Card> {
-		let card = self.face_up.pop()?;
-		if self.face_up.is_empty() {
-			self.flip_up();
-		}
-		Some(card)
+	/// Returns the popped card and whether a card was flipped up.
+	pub fn pop_flip_up(&mut self) -> (Option<Card>, bool) {
+		let card = match self.face_up.pop() {
+			Some(card) => card,
+			None => return (None, false),
+		};
+		let did_flip_up = if self.face_up.is_empty() {
+			self.flip_up()
+		} else {
+			false
+		};
+		(Some(card), did_flip_up)
 	}
 	pub fn take_range<R: RangeBounds<usize>>(&mut self, range: R) -> Stack<UP> {
-		// if self.face_up.get(range).is_none() {
-		// 	return None;
-		// }
 		self.face_up.take_range(range)
 	}
-	pub fn take_range_flip_up<R: RangeBounds<usize>>(&mut self, range: R) -> Stack<UP> {
+	/// Returns the card range and whether a card was flipped up.
+	pub fn take_range_flip_up<R: RangeBounds<usize>>(&mut self, range: R) -> (Stack<UP>, bool) {
 		let cards = self.take_range(range);
-		if self.face_up.is_empty() {
-			self.flip_up();
-		}
-		cards
+		let did_flip_up = if self.face_up.is_empty() {
+			self.flip_up()
+		} else {
+			false
+		};
+		(cards, did_flip_up)
 	}
 	pub fn push(&mut self, card: Card) {
 		self.face_up.push(card);
@@ -298,6 +363,59 @@ impl<const CAP: usize> Pile<CAP, CAP> {
 	}
 }
 
+#[derive(Clone, Debug)]
+pub enum SolveError {
+	MovesBudgetExceeded,
+	StatesBudgetExceeded,
+}
+impl core::fmt::Display for SolveError {
+	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+		write!(f, "{self:?}")
+	}
+}
+impl core::error::Error for SolveError {}
+
+/// The solution tends to be very large with long chains of moves that go back to the same state.
+/// It is recommended to call .clean_solution() if the solution is actually going to be shown to a user.
+pub struct Solution<G: Game> {
+	solution: Vec<StateSnapshot<G>>,
+}
+impl<G: Game + Eq + core::hash::Hash> Solution<G> {
+	pub const fn raw_solution(&self) -> &[StateSnapshot<G>] {
+		self.solution.as_slice()
+	}
+	/// Repeatedly remove the largest range of moves that goes back into the same state.
+	/// This is a very expensive operation when the solution is very long!
+	pub fn clean_solution(self) -> Vec<StateSnapshot<G>> {
+		let mut history = self.solution;
+		// history includes cycles
+		let mut state_index: std::collections::HashMap<_, _> = history
+			.iter()
+			.enumerate()
+			.map(|(i, snapshot)| (snapshot.state().clone(), i))
+			.collect();
+
+		// find the longest range where the start and end are the same state
+		while let Some(longest_range) = history
+			.iter()
+			.enumerate()
+			.filter_map(|(index, snapshot)| {
+				let &last_index = state_index.get(snapshot.state())?;
+				let longness = last_index - index;
+				(longness != 0).then_some(index..last_index)
+			})
+			.max_by_key(|range| range.len())
+		{
+			history.drain(longest_range);
+			for (i, snapshot) in history.iter().enumerate() {
+				state_index.insert(snapshot.state().clone(), i);
+			}
+		}
+
+		history
+	}
+}
+
 #[derive(Clone, Debug)]
 pub enum SessionInstruction<I> {
 	Undo,
@@ -305,49 +423,100 @@ pub enum SessionInstruction<I> {
 }
 
 #[derive(Clone, Debug, Default)]
+#[cfg_attr(
+	feature = "serde",
+	derive(serde_derive::Deserialize, serde_derive::Serialize)
+)]
 pub struct SessionStats<S> {
-	inner_stats: S,
-	undos: usize,
+	inner: S,
+	undos: u32,
 }
 impl<S> SessionStats<S> {
 	pub const fn stats(&self) -> &S {
-		&self.inner_stats
+		&self.inner
 	}
 	const fn increment_undos(&mut self) {
 		self.undos += 1;
 	}
-	pub const fn undos(&self) -> usize {
+	pub const fn undos(&self) -> u32 {
 		self.undos
 	}
 }
+#[derive(Clone, Debug)]
+#[cfg_attr(
+	feature = "serde",
+	derive(serde_derive::Deserialize, serde_derive::Serialize)
+)]
+pub struct SessionConfig<C> {
+	pub inner: C,
+	pub undo_penalty: i32,
+	pub solve_moves_budget: u64,
+	pub solve_states_budget: u64,
+}
+impl<C> SessionConfig<C> {
+	fn new_default(inner: C) -> Self {
+		Self {
+			inner,
+			undo_penalty: -15,
+			solve_moves_budget: 100_000,
+			solve_states_budget: 100_000,
+		}
+	}
+}
+impl<C: Default> Default for SessionConfig<C> {
+	fn default() -> Self {
+		Self::new_default(C::default())
+	}
+}
 
+#[derive(Clone, Debug)]
 pub struct Session<G: Game> {
 	stats: SessionStats<G::Stats>,
-	config: G::Config,
+	config: SessionConfig<G::Config>,
 	state: SessionState<G>,
 }
-#[derive(Clone, Eq, Hash, PartialEq)]
-pub struct SessionState<G: Game> {
-	seed: G,
+#[derive(Clone, Debug)]
+#[cfg_attr(
+	feature = "serde",
+	derive(serde_derive::Deserialize, serde_derive::Serialize)
+)]
+pub struct StateSnapshot<G: Game> {
 	state: G,
-	history: Vec<G::Instruction>,
+	instruction: G::Instruction,
+}
+impl<G: Game> StateSnapshot<G> {
+	pub const fn state(&self) -> &G {
+		&self.state
+	}
+	pub const fn instruction(&self) -> &G::Instruction {
+		&self.instruction
+	}
+}
+#[derive(Clone, Debug)]
+pub struct SessionState<G: Game> {
+	state: G,
+	history: Vec<StateSnapshot<G>>,
 }
 impl<G: Game + Clone> SessionState<G> {
 	fn new(state: G) -> Self {
 		Self {
-			seed: state.clone(),
 			state,
 			history: Vec::new(),
 		}
 	}
 }
-impl<G: Game> Session<G>
+impl<G: Game> SessionState<G> {
+	pub const fn state(&self) -> &G {
+		&self.state
+	}
+}
+impl<G: Game<Score = i32>> Session<G>
 where
-	G: Clone + Eq + core::hash::Hash,
-	G::Stats: Clone + Default,
-	G::Instruction: Clone + Eq + core::hash::Hash,
+	G: Eq + core::hash::Hash,
+	G::Stats: Default,
+	G::Instruction: Eq + core::hash::Hash,
 {
-	pub fn new(state: G, config: G::Config) -> Self {
+	pub fn new(state: G, config: SessionConfig<G::Config>) -> Self {
 		Self {
 			stats: SessionStats::default(),
 			config,
@@ -363,13 +532,13 @@ where
 	pub const fn stats(&self) -> &SessionStats<G::Stats> {
 		&self.stats
 	}
-	pub const fn state(&self) -> &G {
-		&self.state.state
+	pub const fn state(&self) -> &SessionState<G> {
+		&self.state
 	}
-	pub const fn config(&self) -> &G::Config {
+	pub const fn config(&self) -> &SessionConfig<G::Config> {
 		&self.config
 	}
-	pub fn history(&self) -> &[G::Instruction] {
+	pub fn history(&self) -> &[StateSnapshot<G>] {
 		&self.state.history
 	}
 	pub fn undo(&mut self) {
@@ -377,7 +546,7 @@ where
 			.process_instruction(&mut self.stats, &self.config, SessionInstruction::Undo)
 	}
 	pub fn possible_instructions(&self) -> impl Iterator<Item = G::Instruction> + use<G> {
-		self.state.state.possible_instructions()
+		self.state.state.possible_instructions(&self.config.inner)
 	}
 	pub fn process_instruction(&mut self, instruction: G::Instruction) {
 		self.state.process_instruction(
@@ -389,26 +558,71 @@ where
 	pub fn is_win(&self) -> bool {
 		self.state.is_win()
 	}
+	/// Attempt to produce a solution.
+	pub fn solve(&self) -> Result<Option<Solution<G>>, SolveError> {
+		let mut state_moves = std::collections::HashMap::new();
+		let mut session = self.clone();
+		let mut moves = 0;
+		while !session.is_win() {
+			moves += 1;
+			if self.config.solve_moves_budget < moves {
+				return Err(SolveError::MovesBudgetExceeded);
+			}
+			if self.config.solve_states_budget < state_moves.len() as u64 {
+				return Err(SolveError::StatesBudgetExceeded);
+			}
+			// Continue existing iterator if it exists
+			let it = state_moves
+				.entry(session.state().state().clone())
+				.or_insert_with(|| {
+					session
+						.state()
+						.state()
+						.possible_instructions(&self.config().inner)
+				});
+
+			// Run one possible move
+			if let Some(instruction) = it.next() {
+				session.process_instruction(instruction);
+				continue;
+			}
+
+			// No more moves. If we can't undo we're done
+			if session.history().is_empty() {
+				return Ok(None);
+			} else {
+				session.undo();
+			}
+		}
+		Ok(Some(Solution {
+			solution: session.state.history,
+		}))
+	}
 }
-impl<G: Game> Game for SessionState<G>
+impl<G: Game<Score = i32>> Game for SessionState<G>
 where
-	G: Clone,
 	G::Stats: Default,
-	G::Instruction: Clone,
 {
+	type Score = G::Score;
 	type Stats = SessionStats<G::Stats>;
-	type Config = G::Config;
+	type Config = SessionConfig<G::Config>;
 	type Instruction = SessionInstruction<G::Instruction>;
-	fn possible_instructions(&self) -> impl Iterator<Item = Self::Instruction> + use<G> {
+	fn score(&self, stats: &Self::Stats, config: &Self::Config) -> Self::Score {
+		self.state.score(&stats.inner, &config.inner) + stats.undos as i32 * config.undo_penalty
+	}
+	fn possible_instructions(
+		&self,
+		config: &Self::Config,
+	) -> impl Iterator<Item = Self::Instruction> + use<G> {
 		self.state
-			.possible_instructions()
+			.possible_instructions(&config.inner)
 			.map(SessionInstruction::InnerInstruction)
 	}
 	fn is_instruction_valid(&self, config: &Self::Config, instruction: Self::Instruction) -> bool {
 		match instruction {
 			SessionInstruction::Undo => !self.history.is_empty(),
 			SessionInstruction::InnerInstruction(instruction) => {
-				self.state.is_instruction_valid(config, instruction)
+				self.state.is_instruction_valid(&config.inner, instruction)
 			}
 		}
 	}
@@ -420,21 +634,18 @@ where
 	) {
 		match instruction {
 			SessionInstruction::Undo => {
-				// replay the entire history of the game except one move
-				self.history.pop();
-				let mut inner_stats = G::Stats::default();
-				let mut state = self.seed.clone();
-				for instruction in &self.history {
-					state.process_instruction(&mut inner_stats, config, instruction.clone());
+				if let Some(snapshot) = self.history.pop() {
+					self.state = snapshot.state;
+					stats.increment_undos();
 				}
-				self.state = state;
-				stats.inner_stats = inner_stats;
-				stats.increment_undos();
 			}
 			SessionInstruction::InnerInstruction(instruction) => {
-				self.history.push(instruction.clone());
+				self.history.push(StateSnapshot {
+					state: self.state.clone(),
+					instruction: instruction.clone(),
+				});
 				self.state
-					.process_instruction(&mut stats.inner_stats, config, instruction);
+					.process_instruction(&mut stats.inner, &config.inner, instruction);
 			}
 		}
 	}
@@ -442,3 +653,95 @@ where
 		self.state.is_win()
 	}
 }
+
+#[cfg(feature = "serde")]
+impl<'de, G: Game<Score = i32>> serde::de::Deserialize<'de> for Session<G>
+where
+	G: serde::Deserialize<'de> + Clone + Eq + core::hash::Hash,
+	G::Stats: Default,
+	G::Instruction: serde::Deserialize<'de> + Eq + core::hash::Hash,
+	SessionConfig<G::Config>: serde::Deserialize<'de>,
+	Vec<G::Instruction>: serde::Deserialize<'de>,
+{
+	fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+	where
+		D: serde::Deserializer<'de>,
+	{
+		#[derive(serde_derive::Deserialize)]
+		#[serde(bound(deserialize = "
+			G: serde::Deserialize<'de>,
+			SessionConfig<G::Config>: serde::Deserialize<'de>,
+			Vec<G::Instruction>: serde::Deserialize<'de>,
+		"))]
+		struct SerializedSession<G: Game> {
+			config: SessionConfig<G::Config>,
+			initial_state: G,
+			instructions: Vec<G::Instruction>,
+		}
+		let serialized = SerializedSession::deserialize(deserializer)?;
+		let mut session = Session::new(serialized.initial_state, serialized.config);
+		for instruction in serialized.instructions {
+			session.process_instruction(instruction);
+		}
+		Ok(session)
+	}
+}
+#[cfg(feature = "serde")]
+impl<G: Game> serde::Serialize for Session<G>
+where
+	G: serde::Serialize,
+	G::Config: serde::Serialize,
+	G::Instruction: serde::Serialize,
+{
+	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+	where
+		S: serde::Serializer,
+	{
+		struct History<'a, G: Game>(&'a [StateSnapshot<G>]);
+		impl<G: Game> serde::Serialize for History<'_, G>
+		where
+			G: serde::Serialize,
+			G::Instruction: serde::Serialize,
+		{
+			fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+			where
+				S: serde::Serializer,
+			{
+				let &History(history) = self;
+				use serde::ser::SerializeSeq;
+				let mut seq = serializer.serialize_seq(Some(history.len()))?;
+				for snapshot in history {
+					seq.serialize_element(&snapshot.instruction)?;
+				}
+				seq.end()
+			}
+		}
+
+		#[derive(serde_derive::Serialize)]
+		#[serde(bound(serialize = "
+			G: serde::Serialize,
+			SessionConfig<G::Config>: serde::Serialize,
+			G::Instruction: serde::Serialize,
+		"))]
+		struct SerializedSession<'a, G: Game> {
+			config: &'a SessionConfig<G::Config>,
+			initial_state: &'a G,
+			instructions: History<'a, G>,
+		}
+
+		// serialize the initial state of the game.
+		// if there is history, it is the first snapshot's state,
+		// otherwise it is the current game state since there are no moves.
+		let initial_state = if let Some(snapshot) = self.state.history.first() {
+			snapshot.state()
+		} else {
+			&self.state.state
+		};
+		let session = SerializedSession {
+			config: &self.config,
+			initial_state,
+			instructions: History(&self.state.history),
+		};
+		session.serialize(serializer)
+	}
+}

klondike-bench/src/main.rs

@@ -1,5 +1,5 @@
 use card_game::Game;
-use klondike::{Klondike, KlondikeConfig, KlondikeStats, Rng};
+use klondike::{Klondike, KlondikeConfig, KlondikeStats, Rng, ScoringConfig};
 
 const MAX_MOVES: usize = 250;
 
@@ -9,13 +9,15 @@ fn play_to_win(rng: &mut Rng) -> Option<KlondikeStats> {
 	let mut stats = KlondikeStats::new();
 	const CONFIG: KlondikeConfig = KlondikeConfig {
 		draw_stock: klondike::DrawStockConfig::DrawOne,
+		move_from_foundation: klondike::MoveFromFoundationConfig::Allowed,
+		scoring: ScoringConfig::DEFAULT,
 	};
 	// play game a bit
-	while let Some(instruction) = game.get_auto_move()
+	while let Some(instruction) = game.get_auto_move(&CONFIG)
 		&& !game.is_win()
 	{
 		// quit before 250 moves
-		if MAX_MOVES < stats.moves() + 1 {
+		if (MAX_MOVES as u32) < stats.moves() + 1 {
 			return None;
 		}
 
@@ -34,9 +36,9 @@ fn main() {
 	for _ in 0..GAMES {
 		if let Some(stats) = play_to_win(&mut rng) {
 			wins += 1;
-			score_tally[stats.score() / 5] += 1;
-			recycle_tally[stats.recycle_count()] += 1;
-			moves_tally[stats.moves()] += 1;
+			score_tally[(stats.score(&ScoringConfig::DEFAULT) / 5) as usize] += 1;
+			recycle_tally[stats.recycle_count() as usize] += 1;
+			moves_tally[stats.moves() as usize] += 1;
 		}
 	}
 	println!("score_tally={score_tally:?}");

klondike-cli/src/main.rs

@@ -1,23 +1,20 @@
-use card_game::{Card, Game, Pile, Rank, Session, SessionStats, Suit};
+use card_game::{Card, Game, Pile, Rank, Session, Suit};
 use klondike::{
 	DstFoundation, DstTableau, Foundation, Klondike, KlondikeConfig, KlondikeInstruction,
-	KlondikePile, KlondikePileStack, KlondikeStats, SkipCards, Tableau, TableauStack,
+	KlondikePile, KlondikePileStack, SkipCards, Tableau, TableauStack,
 };
 
-// #[cfg(test)]
-// mod test;
-
 use std::fmt::Display;
 struct Displayed<T>(T);
 
 impl Display for Displayed<&Card> {
 	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 		match self.0.rank() {
-			Rank::Ace => write!(f, "A"),
-			Rank::Jack => write!(f, "J"),
-			Rank::Queen => write!(f, "Q"),
-			Rank::King => write!(f, "K"),
-			other => write!(f, "{}", other as u8),
+			Rank::Ace => write!(f, " A"),
+			Rank::Jack => write!(f, " J"),
+			Rank::Queen => write!(f, " Q"),
+			Rank::King => write!(f, " K"),
+			other => write!(f, "{:>2}", other as u8),
 		}?;
 		match self.0.suit() {
 			Suit::Spades => write!(f, "♠"),
@@ -33,7 +30,7 @@ impl Display for OptionalCard<'_> {
 	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 		match self {
 			&OptionalCard(Some(card)) => write!(f, "{}", Displayed(card)),
-			OptionalCard(None) => write!(f, "None"),
+			OptionalCard(None) => write!(f, " []"),
 		}
 	}
 }
@@ -42,16 +39,17 @@ impl Display for Displayed<&Klondike> {
 	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 		// Stock
 		let stock_count = self.0.state().stock().face_down().len();
-		writeln!(f, "Stock: {stock_count}")?;
 
 		// Hand
 		let hand = self.0.state().stock().face_up().last();
-		writeln!(f, "Hand: {}", OptionalCard(hand))?;
 
 		// Foundations
+		writeln!(f, " STOCK       F1  F2  F3  F4")?;
 		write!(
 			f,
-			"Foundations: {} {} {} {}",
+			" {:>2} {}     {} {} {} {}",
+			stock_count,
+			OptionalCard(hand),
 			OptionalCard(self.0.state().foundation1().last()),
 			OptionalCard(self.0.state().foundation2().last()),
 			OptionalCard(self.0.state().foundation3().last()),
@@ -59,42 +57,64 @@ impl Display for Displayed<&Klondike> {
 		)?;
 		writeln!(f)?;
 
-		fn write_pile<const DN: usize, const UP: usize>(
+		writeln!(f, " T1  T2  T3  T4  T5  T6  T7")?;
+
+		fn write_pile_card<const DN: usize, const UP: usize>(
 			f: &mut std::fmt::Formatter<'_>,
 			pile: &Pile<DN, UP>,
-			pile_id: usize,
+			row: usize,
 		) -> std::fmt::Result {
-			write!(f, "T{} ", pile_id)?;
-			for _ in pile.face_down() {
-				write!(f, "]")?;
+			if let Some(_card) = pile.face_down().get(row) {
+				return write!(f, " ⎾⏋"); // └┘ ⨽⨼ ⫭⫬
 			}
-			for card in pile.face_up() {
-				write!(f, "{}", Displayed(card))?;
+			let Some(row) = row.checked_sub(pile.face_down().len()) else {
+				return write!(f, "   ");
+			};
+			if let Some(card) = pile.face_up().get(row) {
+				return write!(f, "{}", Displayed(card));
 			}
-			writeln!(f)?;
-			Ok(())
+			write!(f, "   ")
+		}
+
+		fn write_row(
+			f: &mut std::fmt::Formatter<'_>,
+			game: &Klondike,
+			row: usize,
+		) -> std::fmt::Result {
+			write_pile_card(f, game.state().tableau1(), row)?;
+			write!(f, " ")?;
+			write_pile_card(f, game.state().tableau2(), row)?;
+			write!(f, " ")?;
+			write_pile_card(f, game.state().tableau3(), row)?;
+			write!(f, " ")?;
+			write_pile_card(f, game.state().tableau4(), row)?;
+			write!(f, " ")?;
+			write_pile_card(f, game.state().tableau5(), row)?;
+			write!(f, " ")?;
+			write_pile_card(f, game.state().tableau6(), row)?;
+			write!(f, " ")?;
+			write_pile_card(f, game.state().tableau7(), row)?;
+			writeln!(f)
+		}
+
+		for row in 0..7 + 13 {
+			write_row(f, self.0, row)?;
 		}
-		write_pile(f, self.0.state().tableau1(), 1)?;
-		write_pile(f, self.0.state().tableau2(), 2)?;
-		write_pile(f, self.0.state().tableau3(), 3)?;
-		write_pile(f, self.0.state().tableau4(), 4)?;
-		write_pile(f, self.0.state().tableau5(), 5)?;
-		write_pile(f, self.0.state().tableau6(), 6)?;
-		write_pile(f, self.0.state().tableau7(), 7)?;
 
 		Ok(())
 	}
 }
 
-impl Display for Displayed<&SessionStats<KlondikeStats>> {
+struct DisplayStats<'a>(&'a Session<Klondike>);
+impl Display for DisplayStats<'_> {
 	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 		write!(
 			f,
 			"recycles: {} moves: {} undos: {} score:{}",
-			self.0.stats().recycle_count(),
-			self.0.stats().moves(),
-			self.0.undos(),
-			self.0.stats().score() as isize - self.0.undos() as isize * 15,
+			self.0.stats().stats().recycle_count(),
+			self.0.stats().stats().moves(),
+			self.0.stats().undos(),
+			self.0.state().score(self.0.stats(), self.0.config()),
 		)
 	}
 }
@@ -216,7 +236,7 @@ fn main() -> Result<(), std::io::Error> {
 	use rand::RngExt;
 	let mut rng = rand::rng();
 	// seed from cli argument
-	let mut seed = if let Some(seed) = std::env::args().skip(1).next() {
+	let mut seed = if let Some(seed) = std::env::args().nth(1) {
 		seed.parse().expect("Invalid u64 seed")
 	} else {
 		rng.random()
@@ -226,9 +246,9 @@ fn main() -> Result<(), std::io::Error> {
 	loop {
 		// display stats
 		println!("seed: {seed} ");
-		println!("{}", Displayed(session.stats()));
+		println!("{}", DisplayStats(&session));
 		// display game
-		println!("{}", Displayed(session.state()));
+		println!("{}", Displayed(session.state().state()));
 
 		// parse input
 		input.clear();
@@ -252,7 +272,11 @@ fn main() -> Result<(), std::io::Error> {
 				}
 			}
 			SessionInstruction::Auto => {
-				if let Some(instruction) = session.state().get_auto_move() {
+				if let Some(instruction) = session
+					.state()
+					.state()
+					.get_auto_move(&session.config().inner)
+				{
 					session.process_instruction(instruction);
 				} else {
 					println!("No valid moves!");
@@ -262,9 +286,11 @@ fn main() -> Result<(), std::io::Error> {
 				session.process_instruction(KlondikeInstruction::RotateStock)
 			}
 			SessionInstruction::Klondike(naive_instruction) => {
-				if let Some(instruction) =
-					find_valid_instruction(session.config(), session.state(), naive_instruction)
-				{
+				if let Some(instruction) = find_valid_instruction(
+					&session.config().inner,
+					session.state().state(),
+					naive_instruction,
+				) {
 					session.process_instruction(instruction);
 				} else {
 					println!("Invalid move!");

klondike-cli/src/test.rs

@@ -1,33 +0,0 @@
-use klondike::Klondike;
-use card_game::Session;
-#[test]
-fn test_is_winnable() {
-	// is winnable
-	let is_winnable = Session::new_default(Klondike::with_seed(123)).is_winnable();
-	println!("is_winnable = {is_winnable:?}");
-}
-#[test]
-fn test_klondike() {
-	// create game session
-	let game = Klondike::with_seed(123);
-	let mut session = Session::new_default(game);
-
-	// is winnable
-	let is_winnable = session.is_winnable();
-	println!("is_winnable = {is_winnable:?}");
-
-	// play game
-	while let Some(instruction) = session.possible_instructions().next() {
-		session.process_instruction(instruction);
-	}
-
-	// did win
-	let is_win = session.is_win();
-
-	// print session history
-	for (i, instruction) in session.history().iter().enumerate() {
-		println!("move {i} = {instruction:?}");
-	}
-
-	println!("is_win = {is_win}");
-}

klondike/Cargo.toml

@@ -1,11 +1,23 @@
 [package]
 name = "klondike"
-version = "0.1.0"
+version = "0.4.0"
 edition = "2024"
 
 [dependencies]
 card_game.workspace = true
 rand = { version = "0.10.1", default-features = false, features = ["std_rng"] }
+serde = { version = "1.0.228", default-features = false, optional = true }
+serde_derive = { version = "1.0.228", default-features = false, optional = true }
+
+[dev-dependencies]
+insta = "1.47.2"
+rmp-serde = "1.3.1"
+serde = { version = "1.0.228", default-features = false }
+serde_json = "1.0.149"
 
 [lints]
 workspace = true
+
+[features]
+default = ["serde"]
+serde = ["dep:serde", "dep:serde_derive", "card_game/serde"]

klondike/README.md

@@ -7,18 +7,19 @@ Klondike
 
 ```rust
 use card_game::Session;
-use klondike::Klondike;
+use klondike::{Klondike, KlondikeConfig};
 
 // create game session
 let game = Klondike::with_seed(123);
+let config = KlondikeConfig::default();
 let mut session = Session::new_default(game);
 
 // play game a bit
-while let Some(instruction) = session.state().get_auto_move() {
+while let Some(instruction) = session.state().state().get_auto_move(&config) {
 	session.process_instruction(instruction);
 
-	// quit after 1000 moves
-	if 1000 < session.stats().stats().moves() {
+	// quit after 200 moves or win
+	if session.is_win() || 200 < session.stats().stats().moves() {
 		break;
 	}
 }

klondike/src/lib.rs

@@ -2,53 +2,134 @@ pub type Rng = rand::rngs::StdRng;
 
 use card_game::{Card, Game, Pile, Rank, Stack};
 
+#[cfg(test)]
+mod test;
+
 // test readme
 #[doc = include_str!("../README.md")]
 #[cfg(doctest)]
 struct ReadmeDoctests;
 
-#[derive(Clone, Copy, Debug, Default)]
+#[cfg_attr(
+	feature = "serde",
+	derive(serde_derive::Deserialize, serde_derive::Serialize)
+)]
+#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
 pub enum DrawStockConfig {
 	#[default]
 	DrawOne = 1,
 	DrawThree = 3,
 }
 
+#[cfg_attr(
+	feature = "serde",
+	derive(serde_derive::Deserialize, serde_derive::Serialize)
+)]
+#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
+pub enum MoveFromFoundationConfig {
+	#[default]
+	Allowed,
+	Disallowed,
+}
+
+#[cfg_attr(
+	feature = "serde",
+	derive(serde_derive::Deserialize, serde_derive::Serialize)
+)]
+#[derive(Clone, Copy, Debug)]
+pub struct ScoringConfig {
+	pub move_to_foundation: i32,
+	pub flip_up_bonus: i32,
+	pub move_to_tableau: i32,
+	pub move_from_foundation: i32,
+	pub recycle: i32,
+}
+impl ScoringConfig {
+	pub const DEFAULT: Self = Self {
+		move_to_foundation: 10,
+		flip_up_bonus: 5,
+		move_to_tableau: 5,
+		move_from_foundation: -15,
+		recycle: 0,
+	};
+}
+impl Default for ScoringConfig {
+	fn default() -> Self {
+		Self::DEFAULT
+	}
+}
+
+#[cfg_attr(
+	feature = "serde",
+	derive(serde_derive::Deserialize, serde_derive::Serialize)
+)]
 #[derive(Clone, Debug, Default)]
 pub struct KlondikeConfig {
 	pub draw_stock: DrawStockConfig,
+	pub move_from_foundation: MoveFromFoundationConfig,
+	pub scoring: ScoringConfig,
 }
 
 #[derive(Clone, Debug, Default)]
 pub struct KlondikeStats {
-	score: usize,
-	recycle_count: usize,
-	moves: usize,
+	moves: u32,
+	move_to_foundation_count: u32,
+	flip_up_bonus_count: u32,
+	move_to_tableau_count: u32,
+	move_from_foundation_count: u32,
+	recycle_count: u32,
 }
 impl KlondikeStats {
 	pub const fn new() -> Self {
 		KlondikeStats {
-			score: 0,
-			recycle_count: 0,
 			moves: 0,
+			move_to_foundation_count: 0,
+			flip_up_bonus_count: 0,
+			move_to_tableau_count: 0,
+			move_from_foundation_count: 0,
+			recycle_count: 0,
 		}
 	}
-	pub const fn score(&self) -> usize {
-		self.score
+	pub const fn score(&self, config: &ScoringConfig) -> i32 {
+		self.move_to_foundation_count as i32 * config.move_to_foundation
+			+ self.flip_up_bonus_count as i32 * config.flip_up_bonus
+			+ self.move_to_tableau_count as i32 * config.move_to_tableau
+			+ self.move_from_foundation_count as i32 * config.move_from_foundation
+			+ self.recycle_count as i32 * config.recycle
 	}
-	pub const fn recycle_count(&self) -> usize {
-		self.recycle_count
-	}
-	pub const fn moves(&self) -> usize {
+	pub const fn moves(&self) -> u32 {
 		self.moves
 	}
+	pub const fn move_to_foundation_count(&self) -> u32 {
+		self.move_to_foundation_count
+	}
+	pub const fn flip_up_bonus_count(&self) -> u32 {
+		self.flip_up_bonus_count
+	}
+	pub const fn move_to_tableau_count(&self) -> u32 {
+		self.move_to_tableau_count
+	}
+	pub const fn move_from_foundation_count(&self) -> u32 {
+		self.move_from_foundation_count
+	}
+	pub const fn recycle_count(&self) -> u32 {
+		self.recycle_count
+	}
 	/// A card was moved to a foundation.
-	const fn increment_score_foundation(&mut self) {
-		self.score += 10;
+	const fn increment_move_to_foundation(&mut self) {
+		self.move_to_foundation_count += 1;
+	}
+	/// A card on the tableau was flipped up.
+	const fn increment_flip_up_bonus(&mut self) {
+		self.flip_up_bonus_count += 1;
 	}
 	/// A card was moved from stock to tableau.
-	const fn increment_score_tableau(&mut self) {
-		self.score += 5;
+	const fn increment_move_to_tableau(&mut self) {
+		self.move_to_tableau_count += 1;
+	}
+	/// A card was moved from foundation to tableau.
+	const fn increment_move_from_foundation(&mut self) {
+		self.move_from_foundation_count += 1;
 	}
 	const fn increment_recycle_count(&mut self) {
 		self.recycle_count += 1;
@@ -137,7 +218,6 @@ impl From<Foundation> for KlondikePile {
 	}
 }
 
-#[repr(u8)]
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 pub enum SkipCards {
 	Skip0,
@@ -316,65 +396,81 @@ const fn sum(n: usize) -> usize {
 	n * (n + 1) / 2
 }
 const STOCK: usize = 52 - sum(TABLEAUS);
+const NUM_RANKS: usize = Rank::RANKS.len();
 
+#[cfg_attr(
+	feature = "serde",
+	derive(serde_derive::Deserialize, serde_derive::Serialize)
+)]
 #[derive(Clone, Debug, Eq, Hash, PartialEq)]
 pub struct KlondikeState {
 	stock: Pile<STOCK, STOCK>,
-	foundations: [Stack<13>; 4],
-	tableau1: Pile<0, 13>,
-	tableau2: Pile<1, 13>,
-	tableau3: Pile<2, 13>,
-	tableau4: Pile<3, 13>,
-	tableau5: Pile<4, 13>,
-	tableau6: Pile<5, 13>,
-	tableau7: Pile<6, 13>,
+	foundations: [Stack<NUM_RANKS>; 4],
+	tableau1: Pile<0, NUM_RANKS>,
+	tableau2: Pile<1, NUM_RANKS>,
+	tableau3: Pile<2, NUM_RANKS>,
+	tableau4: Pile<3, NUM_RANKS>,
+	tableau5: Pile<4, NUM_RANKS>,
+	tableau6: Pile<5, NUM_RANKS>,
+	tableau7: Pile<6, NUM_RANKS>,
 }
 impl KlondikeState {
 	pub const fn stock(&self) -> &Pile<STOCK, STOCK> {
 		&self.stock
 	}
-	pub const fn foundation1(&self) -> &Stack<13> {
+	pub const fn foundation1(&self) -> &Stack<NUM_RANKS> {
 		&self.foundations[Foundation::Foundation1 as usize]
 	}
-	pub const fn foundation2(&self) -> &Stack<13> {
+	pub const fn foundation2(&self) -> &Stack<NUM_RANKS> {
 		&self.foundations[Foundation::Foundation2 as usize]
 	}
-	pub const fn foundation3(&self) -> &Stack<13> {
+	pub const fn foundation3(&self) -> &Stack<NUM_RANKS> {
 		&self.foundations[Foundation::Foundation3 as usize]
 	}
-	pub const fn foundation4(&self) -> &Stack<13> {
+	pub const fn foundation4(&self) -> &Stack<NUM_RANKS> {
 		&self.foundations[Foundation::Foundation4 as usize]
 	}
-	pub const fn tableau1(&self) -> &Pile<0, 13> {
+	pub const fn tableau1(&self) -> &Pile<0, NUM_RANKS> {
 		&self.tableau1
 	}
-	pub const fn tableau2(&self) -> &Pile<1, 13> {
+	pub const fn tableau2(&self) -> &Pile<1, NUM_RANKS> {
 		&self.tableau2
 	}
-	pub const fn tableau3(&self) -> &Pile<2, 13> {
+	pub const fn tableau3(&self) -> &Pile<2, NUM_RANKS> {
 		&self.tableau3
 	}
-	pub const fn tableau4(&self) -> &Pile<3, 13> {
+	pub const fn tableau4(&self) -> &Pile<3, NUM_RANKS> {
 		&self.tableau4
 	}
-	pub const fn tableau5(&self) -> &Pile<4, 13> {
+	pub const fn tableau5(&self) -> &Pile<4, NUM_RANKS> {
 		&self.tableau5
 	}
-	pub const fn tableau6(&self) -> &Pile<5, 13> {
+	pub const fn tableau6(&self) -> &Pile<5, NUM_RANKS> {
 		&self.tableau6
 	}
-	pub const fn tableau7(&self) -> &Pile<6, 13> {
+	pub const fn tableau7(&self) -> &Pile<6, NUM_RANKS> {
 		&self.tableau7
 	}
-	pub fn is_tableau_face_down_empty(&self, tableau: Tableau) -> bool {
+	pub fn tableau_face_down_cards(&self, tableau: Tableau) -> &[Card] {
 		match tableau {
-			Tableau::Tableau1 => self.tableau1.face_down().is_empty(),
-			Tableau::Tableau2 => self.tableau2.face_down().is_empty(),
-			Tableau::Tableau3 => self.tableau3.face_down().is_empty(),
-			Tableau::Tableau4 => self.tableau4.face_down().is_empty(),
-			Tableau::Tableau5 => self.tableau5.face_down().is_empty(),
-			Tableau::Tableau6 => self.tableau6.face_down().is_empty(),
-			Tableau::Tableau7 => self.tableau7.face_down().is_empty(),
+			Tableau::Tableau1 => self.tableau1.face_down(),
+			Tableau::Tableau2 => self.tableau2.face_down(),
+			Tableau::Tableau3 => self.tableau3.face_down(),
+			Tableau::Tableau4 => self.tableau4.face_down(),
+			Tableau::Tableau5 => self.tableau5.face_down(),
+			Tableau::Tableau6 => self.tableau6.face_down(),
+			Tableau::Tableau7 => self.tableau7.face_down(),
+		}
+	}
+	pub fn tableau_face_up_cards(&self, tableau: Tableau) -> &[Card] {
+		match tableau {
+			Tableau::Tableau1 => self.tableau1.face_up(),
+			Tableau::Tableau2 => self.tableau2.face_up(),
+			Tableau::Tableau3 => self.tableau3.face_up(),
+			Tableau::Tableau4 => self.tableau4.face_up(),
+			Tableau::Tableau5 => self.tableau5.face_up(),
+			Tableau::Tableau6 => self.tableau6.face_up(),
+			Tableau::Tableau7 => self.tableau7.face_up(),
 		}
 	}
 	pub fn stack_bottom_card(&self, src: KlondikePileStack) -> Option<&Card> {
@@ -382,37 +478,27 @@ impl KlondikeState {
 			KlondikePileStack::Tableau(TableauStack {
 				tableau,
 				skip_cards,
-			}) => match tableau {
-				Tableau::Tableau1 => self.tableau1.face_up().get(skip_cards as usize),
-				Tableau::Tableau2 => self.tableau2.face_up().get(skip_cards as usize),
-				Tableau::Tableau3 => self.tableau3.face_up().get(skip_cards as usize),
-				Tableau::Tableau4 => self.tableau4.face_up().get(skip_cards as usize),
-				Tableau::Tableau5 => self.tableau5.face_up().get(skip_cards as usize),
-				Tableau::Tableau6 => self.tableau6.face_up().get(skip_cards as usize),
-				Tableau::Tableau7 => self.tableau7.face_up().get(skip_cards as usize),
-			},
+			}) => self.tableau_face_up_cards(tableau).get(skip_cards as usize),
 			KlondikePileStack::Foundation(foundation) => {
 				self.foundations[foundation as usize].last()
 			}
 			KlondikePileStack::Stock => self.stock.face_up().last(),
 		}
 	}
-	pub fn top_card<S: Into<KlondikePile>>(&self, src: S) -> Option<&Card> {
-		match src.into() {
-			KlondikePile::Tableau(tableau) => match tableau {
-				Tableau::Tableau1 => self.tableau1.face_up().last(),
-				Tableau::Tableau2 => self.tableau2.face_up().last(),
-				Tableau::Tableau3 => self.tableau3.face_up().last(),
-				Tableau::Tableau4 => self.tableau4.face_up().last(),
-				Tableau::Tableau5 => self.tableau5.face_up().last(),
-				Tableau::Tableau6 => self.tableau6.face_up().last(),
-				Tableau::Tableau7 => self.tableau7.face_up().last(),
-			},
-			KlondikePile::Foundation(foundation) => self.foundations[foundation as usize].last(),
+	pub fn tableau_top_card(&self, tableau: Tableau) -> Option<&Card> {
+		self.tableau_face_up_cards(tableau).last()
+	}
+	pub fn foundation_top_card(&self, foundation: Foundation) -> Option<&Card> {
+		self.foundations[foundation as usize].last()
+	}
+	pub fn top_card(&self, pile: KlondikePile) -> Option<&Card> {
+		match pile {
+			KlondikePile::Tableau(tableau) => self.tableau_top_card(tableau),
+			KlondikePile::Foundation(foundation) => self.foundation_top_card(foundation),
 			KlondikePile::Stock => self.stock.face_up().last(),
 		}
 	}
-	fn take_stack(&mut self, src: KlondikePileStack) -> Stack<13> {
+	fn take_stack_flip_up(&mut self, src: KlondikePileStack) -> (Stack<NUM_RANKS>, bool) {
 		match src {
 			KlondikePileStack::Tableau(TableauStack {
 				tableau,
@@ -426,14 +512,15 @@ impl KlondikeState {
 				Tableau::Tableau6 => self.tableau6.take_range_flip_up(skip_cards as usize..),
 				Tableau::Tableau7 => self.tableau7.take_range_flip_up(skip_cards as usize..),
 			},
-			KlondikePileStack::Foundation(foundation) => {
-				Stack::from_iter(self.foundations[foundation as usize].pop())
-			}
-			KlondikePileStack::Stock => Stack::from_iter(self.stock.pop()),
+			KlondikePileStack::Foundation(foundation) => (
+				Stack::from_iter(self.foundations[foundation as usize].pop()),
+				false,
+			),
+			KlondikePileStack::Stock => (Stack::from_iter(self.stock.pop()), false),
 		}
 	}
-	fn take_top_card<S: Into<KlondikePile>>(&mut self, src: S) -> Option<Card> {
-		match src.into() {
+	fn take_top_card_flip_up(&mut self, pile: KlondikePile) -> (Option<Card>, bool) {
+		match pile {
 			KlondikePile::Tableau(tableau) => match tableau {
 				Tableau::Tableau1 => self.tableau1.pop_flip_up(),
 				Tableau::Tableau2 => self.tableau2.pop_flip_up(),
@@ -443,8 +530,10 @@ impl KlondikeState {
 				Tableau::Tableau6 => self.tableau6.pop_flip_up(),
 				Tableau::Tableau7 => self.tableau7.pop_flip_up(),
 			},
-			KlondikePile::Foundation(foundation) => self.foundations[foundation as usize].pop(),
-			KlondikePile::Stock => self.stock.pop(),
+			KlondikePile::Foundation(foundation) => {
+				(self.foundations[foundation as usize].pop(), false)
+			}
+			KlondikePile::Stock => (self.stock.pop(), false),
 		}
 	}
 	fn extend_foundation<I: IntoIterator<Item = Card>>(
@@ -465,7 +554,11 @@ impl KlondikeState {
 			Tableau::Tableau7 => self.tableau7.extend(cards),
 		}
 	}
-	pub fn is_instruction_valid(&self, instruction: KlondikeInstruction) -> bool {
+	pub fn is_instruction_valid(
+		&self,
+		config: &KlondikeConfig,
+		instruction: KlondikeInstruction,
+	) -> bool {
 		match instruction {
 			// Stock -> Stock draws a card or resets the stock
 			KlondikeInstruction::RotateStock => {
@@ -477,7 +570,7 @@ impl KlondikeState {
 			KlondikeInstruction::DstFoundation(dst_foundation) => {
 				// get the top cards
 				if let Some(src_card) = self.top_card(dst_foundation.src) {
-					match self.top_card(dst_foundation.foundation) {
+					match self.foundation_top_card(dst_foundation.foundation) {
 						// destination card exists
 						Some(dst_card) => {
 							// suit matches?
@@ -494,9 +587,14 @@ impl KlondikeState {
 			}
 			// other = move to tableau
 			KlondikeInstruction::DstTableau(dst_tableau) => {
+				if config.move_from_foundation == MoveFromFoundationConfig::Disallowed
+					&& let KlondikePileStack::Foundation(_) = dst_tableau.src
+				{
+					return false;
+				}
 				// get the cards
 				if let Some(src_card) = self.stack_bottom_card(dst_tableau.src) {
-					match self.top_card(dst_tableau.tableau) {
+					match self.tableau_top_card(dst_tableau.tableau) {
 						// destination card exists
 						Some(dst_card) => {
 							// red-ness is opposite?
@@ -533,7 +631,16 @@ impl Iterator for KlondikeIter {
 		instruction
 	}
 }
+#[test]
+fn test_klondike_iter() {
+	assert_eq!(KlondikeIter::new().count(), 721);
+}
 
+#[cfg_attr(
+	feature = "serde",
+	derive(serde_derive::Deserialize, serde_derive::Serialize),
+	serde(transparent)
+)]
 #[derive(Clone, Debug, Eq, Hash, PartialEq)]
 pub struct Klondike {
 	state: KlondikeState,
@@ -552,7 +659,9 @@ impl Klondike {
 		let mut deck = deck.into_iter();
 
 		// generate tableaus
-		fn pile<const DN: usize>(deck: &mut <Stack<52> as IntoIterator>::IntoIter) -> Pile<DN, 13> {
+		fn pile<const DN: usize>(
+			deck: &mut <Stack<52> as IntoIterator>::IntoIter,
+		) -> Pile<DN, NUM_RANKS> {
 			let stack = Stack::from_iter(deck.take(DN));
 			let mut pile = Pile::new_face_down(stack);
 			pile.push(deck.next().unwrap());
@@ -588,7 +697,7 @@ impl Klondike {
 	/// Check if the game should be auto-completed
 	pub fn is_win_trivial(&self) -> bool {
 		// all face down cards empty means win
-		self.state.stock.face_down().is_empty()
+		self.state.stock.is_empty()
 			&& self.state.tableau1.face_down().is_empty()
 			&& self.state.tableau2.face_down().is_empty()
 			&& self.state.tableau3.face_down().is_empty()
@@ -610,7 +719,7 @@ impl Klondike {
 				KlondikePileStack::Tableau(TableauStack {
 					tableau,
 					skip_cards: SkipCards::Skip0,
-				}) if !self.state().is_tableau_face_down_empty(tableau)
+				}) if !self.state().tableau_face_down_cards(tableau).is_empty()
 					|| self
 						.state()
 						.stack_bottom_card(dst_tableau.src)
@@ -626,15 +735,15 @@ impl Klondike {
 		}
 	}
 	/// A single move that usually makes progress towards a winning game
-	pub fn get_auto_move(&self) -> Option<KlondikeInstruction> {
-		self.possible_instructions()
+	pub fn get_auto_move(&self, config: &KlondikeConfig) -> Option<KlondikeInstruction> {
+		self.possible_instructions(config)
 			.filter(|ins| !ins.is_useless())
 			.min_by_key(|ins| self.instruction_priority(ins))
 	}
 	/// A list of possible moves with useless moves filtered out and sorted by a simple priority function
-	pub fn get_sorted_moves(&self) -> Vec<KlondikeInstruction> {
+	pub fn get_sorted_moves(&self, config: &KlondikeConfig) -> Vec<KlondikeInstruction> {
 		let mut useful_moves: Vec<_> = self
-			.possible_instructions()
+			.possible_instructions(config)
 			.filter(|ins| !ins.is_useless())
 			.collect();
 		useful_moves.sort_by_key(|ins| self.instruction_priority(ins));
@@ -643,15 +752,24 @@ impl Klondike {
 }
 
 impl Game for Klondike {
+	type Score = i32;
 	type Stats = KlondikeStats;
 	type Config = KlondikeConfig;
 	type Instruction = KlondikeInstruction;
-	fn possible_instructions(&self) -> impl Iterator<Item = Self::Instruction> + use<> {
-		let state = self.state.clone();
-		KlondikeIter::new().filter(move |&instruction| state.is_instruction_valid(instruction))
+	fn score(&self, stats: &Self::Stats, config: &Self::Config) -> Self::Score {
+		stats.score(&config.scoring)
 	}
-	fn is_instruction_valid(&self, _config: &Self::Config, instruction: Self::Instruction) -> bool {
-		self.state.is_instruction_valid(instruction)
+	fn possible_instructions(
+		&self,
+		config: &Self::Config,
+	) -> impl Iterator<Item = Self::Instruction> + use<> {
+		let state = self.state.clone();
+		let config = config.clone();
+		KlondikeIter::new()
+			.filter(move |&instruction| state.is_instruction_valid(&config, instruction))
+	}
+	fn is_instruction_valid(&self, config: &Self::Config, instruction: Self::Instruction) -> bool {
+		self.state.is_instruction_valid(config, instruction)
 	}
 	fn process_instruction(
 		&mut self,
@@ -674,16 +792,24 @@ impl Game for Klondike {
 			}
 			// Move a card from anywhere to a foundation
 			KlondikeInstruction::DstFoundation(DstFoundation { src, foundation }) => {
-				stats.increment_score_foundation();
-				let card = self.state.take_top_card(src);
+				stats.increment_move_to_foundation();
+				let (card, did_flip_up) = self.state.take_top_card_flip_up(src);
+				if did_flip_up {
+					stats.increment_flip_up_bonus();
+				}
 				self.state.extend_foundation(foundation, card);
 			}
 			// Move a stack of cards from anywhere to a tableau
 			KlondikeInstruction::DstTableau(DstTableau { src, tableau }) => {
-				if src == KlondikePileStack::Stock {
-					stats.increment_score_tableau();
+				match src {
+					KlondikePileStack::Stock => stats.increment_move_to_tableau(),
+					KlondikePileStack::Foundation(_) => stats.increment_move_from_foundation(),
+					KlondikePileStack::Tableau(_) => {}
+				}
+				let (cards, did_flip_up) = self.state.take_stack_flip_up(src);
+				if did_flip_up {
+					stats.increment_flip_up_bonus();
 				}
-				let cards = self.state.take_stack(src);
 				self.state.extend_tableau(tableau, cards);
 			}
 		}
@@ -699,3 +825,28 @@ impl Game for Klondike {
 		})
 	}
 }
+
+#[cfg(feature = "serde")]
+impl serde::Serialize for KlondikeInstruction {
+	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+	where
+		S: serde::Serializer,
+	{
+		// There is 721 klondike instructions
+		let instruction_id = KlondikeIter::new()
+			.position(|instruction| &instruction == self)
+			.unwrap();
+		serializer.serialize_u16(instruction_id as u16)
+	}
+}
+#[cfg(feature = "serde")]
+impl<'de> serde::Deserialize<'de> for KlondikeInstruction {
+	fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+	where
+		D: serde::Deserializer<'de>,
+	{
+		let instruction_id = u16::deserialize(deserializer)?;
+		let instruction = KlondikeIter::new().nth(instruction_id as usize).unwrap();
+		Ok(instruction)
+	}
+}

klondike/src/snapshots/klondike__test__json.snap

@@ -0,0 +1,5 @@
+---
+source: klondike/src/test.rs
+expression: serialized
+---
+{"config":{"inner":{"draw_stock":"DrawOne","move_from_foundation":"Allowed","scoring":{"move_to_foundation":10,"flip_up_bonus":5,"move_to_tableau":5,"move_from_foundation":-15,"recycle":0}},"undo_penalty":-15,"solve_moves_budget":100000,"solve_states_budget":100000},"initial_state":{"stock":{"face_down":[52,51,21,59,36,45,49,50,22,3,58,39,41,61,13,57,34,56,28,1,19,12,17,5],"face_up":[]},"foundations":[[],[],[],[]],"tableau1":{"face_down":[],"face_up":[40]},"tableau2":{"face_down":[9],"face_up":[4]},"tableau3":{"face_down":[35,8],"face_up":[60]},"tableau4":{"face_down":[11,27,44],"face_up":[25]},"tableau5":{"face_down":[6,7,23,18],"face_up":[29]},"tableau6":{"face_down":[2,55,10,42,24],"face_up":[54]},"tableau7":{"face_down":[26,43,38,53,37,33],"face_up":[20]}},"instructions":[336,100,720,619,606,6,720,19,16,388,497,580,388,720,139,720,19,720,17,31,720,720,720,7,720,720,523,458,720,720,720,720,720,720,720,720,43,43,720,720,720,139,720,19,720,43,720,43,720,720,720,720,720,720,720,720,720,623,619,720,720,720,720,720,720,720,720,720,720,693,281,333,253,209,113,87,720,720,720,720,720,720,720,720,75,223,619,533,74,2,720,116,331,279,279,305,305,29,25,24,12,37,25,222,24,42,126,471,720,720,720,362,292,331,253,720,19,720,183,151,12,67,336,61,93,235,720,7,2,0,7,38,26,14,27,15,26,36,0,7,3,6,18,43,36,24,12,0,1,19,38,26,39,27,15,38,26,36]}

klondike/src/snapshots/klondike__test__save_rmp.snap

@@ -0,0 +1,6 @@
+---
+source: klondike/src/test.rs
+expression: serialized
+extension: bin
+snapshot_kind: binary
+---

klondike/src/test.rs

@@ -0,0 +1,55 @@
+use crate::Klondike;
+use card_game::Session;
+
+#[test]
+fn test_is_winnable() {
+	// is winnable
+	let solution_result = Session::new_default(Klondike::with_seed(124)).solve();
+	if let Ok(Some(solution)) = solution_result {
+		let win_moves = solution.clean_solution();
+		// for (i, ins) in win_moves.into_iter().enumerate() {
+		// 	println!("{i} = {:?}", ins.instruction());
+		// }
+		println!("Game is winnable with {} moves", win_moves.len());
+	} else {
+		println!("Game is not winnable");
+	}
+}
+
+#[cfg(feature = "serde")]
+#[test]
+fn test_json() {
+	let mut session = Session::new_default(Klondike::with_seed(124));
+	let solution_result = session.solve();
+	if let Ok(Some(solution)) = solution_result {
+		for snapshot in solution.clean_solution() {
+			session.process_instruction(snapshot.instruction().clone());
+		}
+	}
+	let serialized = serde_json::to_string(&session).unwrap();
+	println!("serialized = {serialized}");
+	let round_trip_session: Session<Klondike> = serde_json::from_str(&serialized).unwrap();
+	let serialized2 = serde_json::to_string(&round_trip_session).unwrap();
+	assert_eq!(serialized, serialized2);
+
+	insta::assert_snapshot!(serialized);
+}
+
+#[cfg(feature = "serde")]
+#[test]
+fn test_rmp() {
+	let mut session = Session::new_default(Klondike::with_seed(124));
+	let solution_result = session.solve();
+	if let Ok(Some(solution)) = solution_result {
+		for snapshot in solution.clean_solution() {
+			session.process_instruction(snapshot.instruction().clone());
+		}
+	}
+	let serialized = rmp_serde::to_vec(&session).unwrap();
+	println!("serialized.len() = {}", serialized.len());
+	let round_trip_session: Session<Klondike> = rmp_serde::from_slice(&serialized).unwrap();
+	let serialized2 = rmp_serde::to_vec(&round_trip_session).unwrap();
+	assert_eq!(serialized, serialized2);
+
+	insta::assert_binary_snapshot!("save_rmp.bin", serialized);
+}