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If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. diff --git a/README.md b/README.md new file mode 100644 --- /dev/null +++ b/README.md @@ -0,0 +1,31 @@ +Snorkels is a two person strategy board game. You can find the [rules +here][rules]. This is an implementation of Snorkels written in Haskell. + +[rules]: http://nestorgames.com/rulebooks/SNORKELS_EN.pdf + +It features: + +- Support for up to 5 players. +- Colored output. +- Player switching. + +Coming up are: + +- Computer player agents. +- Network games. + + +# Installation + +User-wide: + + cabal install + cabal configure + cabal copy + +Sandboxed: + + cabal sandbox + cabal install + cabal configure + cabal run diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/snorkels.cabal b/snorkels.cabal new file mode 100644 --- /dev/null +++ b/snorkels.cabal @@ -0,0 +1,108 @@ +-- Initial snorkels.cabal generated by cabal init. For further +-- documentation, see http://haskell.org/cabal/users-guide/ + +-- The name of the package. +name: snorkels + +-- The package version. See the Haskell package versioning policy (PVP) +-- for standards guiding when and how versions should be incremented. +-- http://www.haskell.org/haskellwiki/Package_versioning_policy +-- PVP summary: +-+------- breaking API changes +-- | | +----- non-breaking API additions +-- | | | +--- code changes with no API change +version: 0.2.0.0 + +-- A short (one-line) description of the package. +synopsis: Strategic board game of medium complexity + +-- A longer description of the package. +description: Implementation in Haskell of the strategic board game + Snorkels. Snorkels is often used as a first step when + teaching people to play Go. + +-- The license under which the package is released. +license: GPL-3 + +-- The file containing the license text. +license-file: LICENSE + +-- The package author(s). +author: Linus Heckemann & Unai Zalakain + +-- An email address to which users can send suggestions, bug reports, and +-- patches. +maintainer: linus@sphalerite.org & contact@unaizalakain.info + +-- A copyright notice. +-- copyright: + +category: Game + +build-type: Simple + +-- Extra files to be distributed with the package, such as examples or a +-- README. +extra-source-files: README.md + +-- Constraint on the version of Cabal needed to build this package. +cabal-version: >=1.10 + + +executable snorkels + -- .hs or .lhs file containing the Main module. + main-is: Main.hs + + -- Modules included in this executable, other than Main. + -- other-modules: + + -- LANGUAGE extensions used by modules in this package. + other-extensions: FlexibleInstances + + -- Other library packages from which modules are imported. + build-depends: base >=4.8 && <4.9, + monad-loops >=0.4 && <0.5, + random >=1.1 && <1.2, + containers >=0.5 && <0.6, + ansi-terminal >=0.6 && <0.7, + bimap >=0.3.2 && <0.3.3, + parsec >=3.1.11 && <3.1.12, + optparse-applicative >=0.13.0 && <0.13.1 + + -- Directories containing source files. + hs-source-dirs: src + + -- Base language which the package is written in. + default-language: Haskell2010 + + +library + -- Modules exported by the library. + exposed-modules: Snorkels.CLI, + Snorkels.Board, + Snorkels.Game, + Snorkels.Types, + Snorkels.Play, + Snorkels.RandomAgent + + -- Modules included in this library but not exported. + -- other-modules: + + -- LANGUAGE extensions used by modules in this package. + other-extensions: FlexibleInstances + + -- Other library packages from which modules are imported. + build-depends: base >=4.8 && <4.9, + monad-loops >=0.4 && <0.5, + random >=1.1 && <1.2, + containers >=0.5 && <0.6, + ansi-terminal >=0.6 && <0.7, + bimap >=0.3.2 && <0.3.3, + parsec >=3.1.11 && <3.1.12, + optparse-applicative >=0.13.0 && <0.13.1 + + -- Directories containing source files. + hs-source-dirs: src + + -- Base language which the package is written in. + default-language: Haskell2010 + diff --git a/src/Main.hs b/src/Main.hs new file mode 100644 --- /dev/null +++ b/src/Main.hs @@ -0,0 +1,98 @@ +module Main where + +import qualified Data.Bimap as Bimap +import Data.Function +import qualified Data.Map.Strict as Map +import Data.Monoid +import System.Random (getStdGen) + +import Options.Applicative + +import Snorkels.Types +import Snorkels.Play +import Snorkels.CLI (cli) +import Snorkels.RandomAgent (randomAgent) +import qualified Snorkels.Board as B + + +data MainParser = MainParser { optPlayers :: [PlayerConfig] + , optNumStones :: Int + , optWidth :: Int + , optHeight :: Int + } deriving (Eq) + + +data PlayerConfig = Local | Computer + deriving (Eq, Show) + + +localParser :: Parser PlayerConfig +localParser = flag' Local (short 'l') + + +computerParser :: Parser PlayerConfig +computerParser = flag' Computer (short 'c') + + +mainParser :: Parser MainParser +mainParser = MainParser + <$> many (localParser <|> computerParser) + <*> option auto + ( long "stones" + <> short 's' + <> value 3 + <> metavar "#STONES" + <> help "Number of stones randomly thrown on the board" + ) + <*> option auto + ( long "width" + <> short 'w' + <> value 7 + <> metavar "WIDTH" + <> help "Width of the board" + ) + <*> option auto + ( long "height" + <> short 'h' + <> value 7 + <> metavar "HEIGHT" + <> help "Height of the board" + ) + + +getPlayerType :: PlayerConfig -> PlayerType +getPlayerType Local = cli +getPlayerType Computer = randomAgent + + +create :: MainParser -> IO (Either String Game) +create options + | max (options&optWidth) (options&optHeight) > 26 = return $ Left "Cannot have more than 26 on either axis." + | length (options&optPlayers) < 2 = return $ Left "Snorkels must be played by at least 2 players." + | otherwise = do g <- getStdGen + return $ B.throwStones game (options&optNumStones) g + where players = Map.fromList [(p, getPlayerType c) | (p, c) <- zip [Green ..] (options&optPlayers)] + game = Game { pieces = Map.empty + , boardSize = (optWidth options, optHeight options) + , playerTypes = players + , currentPlayer = Green + , switches = Bimap.empty + } + + +run :: MainParser -> IO () +run options = do game <- create options + case game of + Left message -> print message + Right g -> do play g + return () + + +main :: IO () +main = execParser opts >>= run + where + opts = info (helper <*> mainParser) + ( fullDesc + <> progDesc "TODO" + <> header "Snorkels -- strategic board game") + diff --git a/src/Snorkels/Board.hs b/src/Snorkels/Board.hs new file mode 100644 --- /dev/null +++ b/src/Snorkels/Board.hs @@ -0,0 +1,187 @@ +module Snorkels.Board ( + -- * Checkers + isValid + , isTrapped + , hasLost + -- * Generators + , neighbours + , allPositions + , freePositions + , growGroup + , groupFrom + , getGroups + -- * Filters + , areValid + , areNeighbours + , arePieces + , areSnorkels + , areFromPlayer + -- * Manipulation + , getPiece + , putPiece + , shufflePositions + , throwStones + ) where + +import Control.Monad (mfilter) +import Data.Function +import Data.Maybe +import System.Random (RandomGen, randomRs) +import qualified Data.Map.Strict as Map +import qualified Data.Set as Set + +import Snorkels.Types + + +-- | +-- Given some @(min, max)@ bounds, check if an 'Int' is in them. +-- @min@ is inclusive, @max@ isn't. +inRange :: (Int, Int) -> Int -> Bool +inRange (min, max) check = min <= check && check < max + +-- | +-- Given some @(maxWidth, maxHeight)@ bounds and a 'Position', check whether the +-- 'Position' is within those bounds. +inBounds :: (Int, Int) -> Position -> Bool +inBounds (maxX, maxY) (x, y) = inRange (0, maxX) x && inRange (0, maxY) y + +-- | +-- Offset by @(x, y)@ a 'Position' to obtain a new one +offset :: (Int, Int) -> Position -> Position +offset (x, y) (x2, y2) = (x+x2, y+y2) + +-- | +-- Given a 'Position', get the 'Set.Set' of 'Position's that are immediatelly +-- above, under, to the left, or to the right. +neighbours :: Position -> Set.Set Position +neighbours position = Set.map (`offset` position) neighbourOffsets + where neighbourOffsets = Set.fromList [(-1, 0), (1, 0), (0, -1), (0, 1)] + +-- | +-- Check if some 'Position' is within the bounds of a board +isValid :: Game -> Position -> Bool +isValid game = inBounds $ game&boardSize + +-- | +-- Check if some 'Position's are within the bounds of a game +areValid :: Game -> Set.Set Position -> Set.Set Position +areValid game = Set.filter (isValid game) + +-- | +-- Get all the 'Position's that are within a board +allPositions :: Game -> Set.Set Position +allPositions game = Set.fromList [(x, y) | x <- [0..width-1], y <- [0..height-1]] + where (width, height) = game&boardSize + +-- | +-- Get all the 'Position's that are within a board and that haven't been already +-- occupied. +freePositions :: Game -> Set.Set Position +freePositions game = Set.filter (flip Map.notMember $ game&pieces) + . allPositions + $ game + +-- | +-- Get all the neighbour 'Position's of some 'Position's within a board. +areNeighbours :: Game -> Set.Set Position -> Set.Set Position +areNeighbours game positions = areValid game + . flip Set.difference positions + . Set.unions + . map neighbours + $ Set.toList positions + +-- | +-- Filter 'Position's only leaving those which have a 'Piece' in some board. +arePieces :: Game -> Set.Set Position -> Set.Set Position +arePieces game = Set.intersection (Map.keysSet (game&pieces)) . areValid game + +-- | +-- Filter 'Position's only leaving those which have a 'Snorkel' in some board. +areSnorkels :: Game -> Set.Set Position -> Set.Set Position +areSnorkels game = Set.filter (maybe False isSnorkel . getPiece game) . arePieces game + +-- | +-- Filter 'Position's only leaving those which have a 'Snorkel' of the given +-- 'Player' in some board. +areFromPlayer :: Game -> Player -> Set.Set Position -> Set.Set Position +areFromPlayer game player = Set.filter (maybe False fromPlayer . getPiece game) . areSnorkels game + where fromPlayer = maybe False (player ==) . getPlayer + +-- | +-- Put into a 'Group' 'Position's that are immediate neighbours. +growGroup :: Game -> Group -> Group +growGroup game initial + | Set.null new = initial + | otherwise = growGroup game group + where group = Group {positions = Set.union initialPositions new, player = owner} + new = areFromPlayer game owner $ areNeighbours game initialPositions + initialPositions = initial&positions + owner = initial&player + +-- TODO: Should this return a Maybe Group (to account for the possibility of the +-- given position on the board being empty) or allow groups of empty positions +-- too? Such groups might be useful for AI if we ever dare go there. +-- | +-- Form a 'Group' from an initial 'Position' putting all the 'Position's with +-- 'Snorkel's from the same 'Player' that are connected, vertically or +-- horizontally, and by 'Snorkel's of the same 'Player', to the initial +-- 'Position' +groupFrom :: Game -> Position -> Maybe Group +groupFrom game pos = growGroup game <$> (groupForPlayer <$> owner) + where groupForPlayer p = Group {positions = Set.singleton pos, player = p} + owner = mfilter isSnorkel (getPiece game pos) >>= getPlayer + +-- | +-- Get all the 'Group's on the board. +getGroups :: Game -> Set.Set Group +getGroups game = Set.map fromJust + . Set.filter isJust + . Set.map (groupFrom game) + $ allPositions game + +-- | +-- Check whether a given 'Group' is trapped by having all its surrounding +-- positions taken by 'Stone's or 'Snorkel's from some other 'Player'. +isTrapped :: Game -> Group -> Bool +isTrapped game group = all (isBlocking (group&player) . getPiece game) + (Set.toList $ areNeighbours game $ group&positions) + +-- | +-- Check whether the given 'Player' has one of its snorkel 'Group's trapped. +hasLost :: Game -> Player -> Bool +hasLost game p = any (isTrapped game) + (filter ((== p) . player) $ Set.toList $ getGroups game) + + +-- | +-- Get whatever is at the given 'Position' on the board. +getPiece :: Game -> Position -> Maybe Piece +getPiece game pos = Map.lookup pos $ game&pieces + + +-- | +-- Put a 'Piece' at the given 'Position' on the board. +putPiece :: Game -> Position -> Piece -> Game +putPiece game pos piece = game {pieces = Map.insert pos piece $ game&pieces} + + +-- | +-- Given a 'Set.Set' of 'Position's, get them in an ordered random list. +shufflePositions :: RandomGen g => Set.Set Position -> g -> [Position] +shufflePositions positions g = map (p !!) $ randomRs (0, length p - 1) g + where p = Set.toList positions + + +throwStone :: RandomGen g => Game -> g -> Either String Game +throwStone game g + | null $ freePositions game = Left "There is no place to throw a stone." + | otherwise = Right $ putPiece game pos Stone + where pos = head $ shufflePositions (freePositions game) g + +-- | +-- Randomly throw the given number of 'Stone's on the board. +throwStones :: RandomGen g => Game -> Int -> g -> Either String Game +throwStones game 0 _ = Right game +throwStones game n g = case throwStone game g of + Right game -> throwStones game (n-1) g + Left message -> Left message diff --git a/src/Snorkels/CLI.hs b/src/Snorkels/CLI.hs new file mode 100644 --- /dev/null +++ b/src/Snorkels/CLI.hs @@ -0,0 +1,120 @@ +{-# LANGUAGE FlexibleInstances #-} + +module Snorkels.CLI ( cli ) where + +import Control.Monad +import Data.Char +import Data.Function +import Data.List +import System.IO (hFlush, stdout) +import Text.Printf (printf) +import Text.Parsec (parse, (<|>)) +import Text.Parsec.Char (string, spaces, oneOf) +import Text.Parsec.String (Parser) +import Text.Parsec.Combinator (choice) +import qualified Data.Bimap as Bimap +import qualified Data.Map.Strict as Map +import qualified System.Console.ANSI as ANSI + +import Snorkels.Types +import qualified Snorkels.Board as B +import qualified Snorkels.Game as G + + +class Displayable a where + display :: a -> String + + +snorkelColour c = ANSI.setSGRCode [ANSI.SetColor ANSI.Foreground ANSI.Vivid c] +reset = ANSI.setSGRCode [ANSI.Reset] + +instance Displayable (Maybe Piece) where + display s = case s of + (Just (Snorkel Green)) -> concat [snorkelColour ANSI.Green, "G", reset] + (Just (Snorkel Purple)) -> concat [snorkelColour ANSI.Magenta, "P", reset] + (Just (Snorkel Red)) -> concat [snorkelColour ANSI.Red, "R", reset] + (Just (Snorkel Yellow)) -> concat [snorkelColour ANSI.Yellow, "Y", reset] + (Just (Snorkel Cyan)) -> concat [snorkelColour ANSI.Cyan, "C", reset] + (Just Stone) -> "*" + Nothing -> " " + +yCoords = ['a'..'z'] +xCoords = ['A'..'Z'] + +instance Displayable Game where + display g = intercalate "\n" $ [headerCoords, header] ++ [line y | y <- [0..height-1]] ++ [footer] + where (width, height) = g&boardSize + headerCoords = " " ++ intersperse ' ' (take width xCoords) + header = " ." ++ replicate (width*2-1) '_' ++ "." + footer = " '" ++ replicate (width*2-1) '-' ++ "'" + piece x y = display (B.getPiece g (x, y)) + line y = yCoords !! y : " |" ++ intercalate "." [piece x y | x <- [0..width-1]] ++ "|" + + +playerRepr :: Bimap.Bimap Player String +playerRepr = Bimap.fromList [(p, show p) | p <- [Green ..]] + + +moveParser :: Parser (Maybe Position) +moveParser = do spaces + x <- oneOf xCoords + spaces + y <- oneOf yCoords + spaces + case (x `elemIndex` xCoords, y `elemIndex` yCoords) of + (Just x, Just y) -> return $ Just (x, y) + _ -> fail "Introduce move in the form of X y" + + +quitParser :: Parser (Maybe Position) +quitParser = do spaces + string "quit" + spaces + return Nothing + + +moveOrQuitParser :: Parser (Maybe Position) +moveOrQuitParser = moveParser <|> quitParser + + +switchParser :: Parser Player +switchParser = do spaces + player <- choice $ map string $ Bimap.keysR playerRepr + spaces + return $ playerRepr Bimap.!> player + + +readParser :: Parser a -> Game -> IO a +readParser parser game = do putStr $ printf "%s: " $ show $ game¤tPlayer + hFlush stdout + input <- getLine + case parse parser "" input of + Left parseError -> do print parseError + readParser parser game + Right result -> return result + + +cliMove :: Game -> Maybe String -> IO (Maybe Position) +cliMove game errorMessage = do putStrLn $ display game + mapM_ putStrLn errorMessage + readParser moveOrQuitParser game + + +cliSwitch :: Game -> Maybe String -> IO Player +cliSwitch game errorMessage = do putStrLn $ display game + mapM_ putStrLn errorMessage + putStr "Pick the color you want to switch to: " + print $ G.validSwitches game + readParser switchParser game + + +cliReportWinner :: Game -> Player -> IO () +cliReportWinner game player = do putStrLn $ display game + putStrLn $ printf "%s has won!" $ show player + +cli :: PlayerType +cli = PlayerType { getMove = cliMove + , getSwitch = cliSwitch + , reportWinner = cliReportWinner + , isLocal = True + } diff --git a/src/Snorkels/Game.hs b/src/Snorkels/Game.hs new file mode 100644 --- /dev/null +++ b/src/Snorkels/Game.hs @@ -0,0 +1,81 @@ +module Snorkels.Game ( move + , switch + , quit + , getSurvivors + , getNextPlayer + , getWinner + , hasFinished + , validSwitches + , makeSwitches + ) where + +import Data.Function +import Data.Maybe +import Data.List +import qualified Data.Bimap as Bimap +import qualified Data.Map.Strict as Map +import qualified Data.Set as Set + +import Snorkels.Types +import qualified Snorkels.Board as B + + +getSurvivors :: Game -> [Player] +getSurvivors game = case filter hasSurvived players of + [] -> [game¤tPlayer] + s -> s + where hasSurvived = not . B.hasLost game + players = Map.keys $ game&playerTypes + + +getNextPlayer :: Game -> Maybe Player +getNextPlayer game = listToMaybe + . drop 1 + . dropWhile (/= (game¤tPlayer)) + $ cycle + $ getSurvivors game + + +advancePlayer :: Game -> Game +advancePlayer game = game {currentPlayer = fromJust (getNextPlayer game)} + + +quit :: Game -> Game +quit game = (advancePlayer game) {playerTypes = Map.delete (game¤tPlayer) (game&playerTypes)} + + +move :: Position -> Game -> Either String Game +move pos game + | not validPosition = Left "Cannot place a snorkel there." + | not survivors = Left "No surviving players left." + | otherwise = Right $ advancePlayer . putSnorkel $ game + where validPosition = elem pos $ B.freePositions game + survivors = isJust $ getNextPlayer game + putSnorkel g = B.putPiece g pos $ Snorkel (game¤tPlayer) + + +validSwitches :: Game -> [Player] +validSwitches game = getSurvivors game \\ Bimap.keysR (game&switches) + + +switch :: Player -> Game -> Either String Game +switch player game + | player `notElem` validSwitches game = Left "Cannot switch to such color." + | otherwise = Right $ nextPlayer . putSwitch $ game + where putSwitch g = g {switches = Bimap.insert (g¤tPlayer) player (g&switches)} + nextPlayer g = g {currentPlayer = fromJust (getNextPlayer g)} + + +makeSwitches :: Game -> Game +makeSwitches game = game {playerTypes = Map.mapKeys getChosen $ game&playerTypes} + where getChosen p = fromMaybe p (Bimap.lookup p $ game&switches) + + +getWinner :: Game -> Maybe Player +getWinner game = case getSurvivors game of + [x] -> Just x + _ -> Nothing + + +hasFinished :: Game -> Bool +hasFinished = isJust . getWinner diff --git a/src/Snorkels/Play.hs b/src/Snorkels/Play.hs new file mode 100644 --- /dev/null +++ b/src/Snorkels/Play.hs @@ -0,0 +1,62 @@ +module Snorkels.Play ( play ) where + + +import Control.Monad.Loops (iterateUntilM) +import Data.Function +import qualified Data.Map.Strict as Map +import Data.Maybe +import Data.List (partition) + +import Snorkels.Types +import qualified Snorkels.Game as G + + +getCurrentPlayerType :: Game -> PlayerType +getCurrentPlayerType game = (game&playerTypes) Map.! (game¤tPlayer) + + +playMove :: Game -> Maybe String -> IO Game +playMove game errorMessage = do move <- getMove pt game errorMessage + case move of + Nothing -> return $ G.quit game + Just pos -> case G.move pos game of + Left message -> playMove game $ Just message + Right game -> return game + where pt = getCurrentPlayerType game + + +playSwitch :: Game -> Maybe String -> IO Game +playSwitch game errorMessage = do pos <- getSwitch pt game errorMessage + case G.switch pos game of + Left message -> playSwitch game $ Just message + Right game -> return game + where pt = getCurrentPlayerType game + + +playRound :: (Game -> Maybe String -> IO Game) -> Game -> IO Game +playRound playFunc game = do g <- playFunc game Nothing + if G.hasFinished g || ((game¤tPlayer) > (g¤tPlayer)) + then return g + else playRound playFunc g + + +reportWinnerAround :: Game -> IO () +reportWinnerAround game = case G.getWinner game of + Just winner -> do mapM_ (reportToPT winner) nonlocals + maybe (return ()) (reportToPT winner) (listToMaybe locals) + Nothing -> return () + where pts = Map.elems $ game&playerTypes + (locals, nonlocals) = partition isLocal pts + reportToPT winner pt = reportWinner pt game winner + + + +play :: Game -> IO Game +play game = do g <- playRound playMove game + -- The first moving round is over, ask for switches + g <- G.makeSwitches <$> playRound playSwitch g + -- Continue until finished + g <- iterateUntilM G.hasFinished (playRound playMove) g + -- The game has now finished + reportWinnerAround g + return g diff --git a/src/Snorkels/RandomAgent.hs b/src/Snorkels/RandomAgent.hs new file mode 100644 --- /dev/null +++ b/src/Snorkels/RandomAgent.hs @@ -0,0 +1,37 @@ +{-# LANGUAGE FlexibleInstances #-} + +module Snorkels.RandomAgent ( randomAgent ) where + +import Control.Monad +import Data.Char +import Data.Function +import Data.List +import qualified Data.Bimap as Bimap +import qualified Data.Map.Strict as Map +import System.Random (getStdGen) + +import Snorkels.Types +import qualified Snorkels.Board as B +import qualified Snorkels.Game as G + + +randomMove :: Game -> Maybe String -> IO (Maybe Position) +randomMove game errorMessage = do g <- getStdGen + case B.shufflePositions (B.freePositions game) g of + [] -> return Nothing + (x:xs) -> return $ Just x + + +randomSwitch :: Game -> Maybe String -> IO Player +randomSwitch game errorMessage = return $ head $ G.validSwitches game + + +randomReportWinner :: Game -> Player -> IO () +randomReportWinner game player = return () + +randomAgent :: PlayerType +randomAgent = PlayerType { getMove = randomMove + , getSwitch = randomSwitch + , reportWinner = randomReportWinner + , isLocal = False + } diff --git a/src/Snorkels/Types.hs b/src/Snorkels/Types.hs new file mode 100644 --- /dev/null +++ b/src/Snorkels/Types.hs @@ -0,0 +1,91 @@ +module Snorkels.Types ( Position + , Snorkel (..) + , Player + , Group (..) + , Piece (..) + , Game (..) + , isSnorkel + , getPlayer + , isBlocking + , PlayerType (..) + ) where + +import qualified Data.Bimap as Bimap +import qualified Data.Map.Strict as Map +import qualified Data.Set as Set + + +-- | Some (x, y) coordinate on the board +type Position = (Int, Int) + + +-- | Some player's pieces' color +data Snorkel = Green | Purple | Red | Yellow | Cyan + deriving (Show, Eq, Ord, Enum, Read) + + +-- | Each player has a distinctive color +type Player = Snorkel + + +-- | +-- An horizontally or vertically connected group of 'Snorkel's that belong to +-- the same 'Player' +data Group = Group { positions :: Set.Set Position + , player :: Player + } deriving (Show, Eq, Ord) + + +-- | +-- Any type of piece on the board: either a 'Snorkel' or a 'Stone' +data Piece = Snorkel Snorkel | Stone + deriving (Show, Eq) + + +-- This is just a shortcut for (isJust . getPlayer) +-- | Check whether the 'Piece' is a 'Snorkel' +isSnorkel :: Piece -> Bool +isSnorkel Stone = False +isSnorkel _ = True + + +-- | Get the player owning the 'Piece' or 'Nothing' if the piece is a 'Stone' +getPlayer :: Piece -> Maybe Player +getPlayer Stone = Nothing +getPlayer (Snorkel p) = Just p + + +-- | +-- Check whether the contents of a given 'Position' on the board suppose a block +-- for a given 'Player'. Only 'Stone's and 'Snorkel's from a different 'Player' +-- suppose a block. +isBlocking :: Player -> Maybe Piece -> Bool +isBlocking _ Nothing = False +isBlocking player (Just piece) = maybe True (/= player) (getPlayer piece) + + +data PlayerType = PlayerType { + -- | Maybe print an error message and get a position to move to or a quit. + getMove :: Game -> Maybe String -> IO (Maybe Position) + -- | Maybe print an error message and get a player to switch to. + , getSwitch :: Game -> Maybe String -> IO Player + -- | Report the player about the winner of the game + , reportWinner :: Game -> Player -> IO () + -- | Only one of the playertypes marked as local is notified about the + -- winner. FIXME: There must be a cleverer way of doing this. + , isLocal :: Bool +} + + +data Game = Game { + -- | Only 'Position's occupied by 'Piece's are here + pieces :: Map.Map Position Piece + -- | Width and height limits of the board + , boardSize :: (Int, Int) + -- | List of 'Player's that didn't 'Quit' + , playerTypes :: Map.Map Player PlayerType + -- | 'Player' that plays next + , currentPlayer :: Player + -- | Map of what each player chooses to be when asked to switch + , switches :: Bimap.Bimap Player Player +}