{-# LANGUAGE FlexibleInstances, MultiParamTypeClasses #-}
{-
Copyright (C) 2018 Dr. Alistair Ward
This file is part of BishBosh.
BishBosh is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
BishBosh is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with BishBosh. If not, see .
-}
{- |
[@AUTHOR@] Dr. Alistair Ward
[@DESCRIPTION@]
* Defines the state of the game, without regard to how it arrived there; .
* Games with the same /position/ have the same opportunities.
* N.B.: /piece/s are fungible, i.e. they lack identity, so the location of identical /piece/s may be exchanged, without altering the /position/.
-}
module BishBosh.State.Position(
-- * Types
-- ** Data-types
Position(
-- MkPosition,
-- getNextLogicalColour,
-- getMaybePieceByCoordinates,
-- getCastleableRooksByLogicalColour,
getMaybeEnPassantAbscissa
),
-- * Functions
-- ** Constructors
mkPosition
) where
import qualified BishBosh.Attribute.LogicalColour as Attribute.LogicalColour
import qualified BishBosh.Component.Turn as Component.Turn
import qualified BishBosh.Component.Zobrist as Component.Zobrist
import qualified BishBosh.Property.Opposable as Property.Opposable
import qualified BishBosh.Property.Reflectable as Property.Reflectable
import qualified BishBosh.State.CastleableRooksByLogicalColour as State.CastleableRooksByLogicalColour
import qualified BishBosh.State.EnPassantAbscissa as State.EnPassantAbscissa
import qualified BishBosh.State.MaybePieceByCoordinates as State.MaybePieceByCoordinates
import qualified BishBosh.Types as T
import qualified Control.DeepSeq
import qualified Data.Array.IArray
import qualified Data.Maybe
{- |
* The state of the game, without regard to how it arrived there; .
* Games with the same /position/ may be considered to have converged, since they now have equal opportunity.
-}
data Position x y = MkPosition {
getNextLogicalColour :: Attribute.LogicalColour.LogicalColour, -- ^ The next player to move.
getMaybePieceByCoordinates :: State.MaybePieceByCoordinates.MaybePieceByCoordinates x y,
getCastleableRooksByLogicalColour :: State.CastleableRooksByLogicalColour.CastleableRooksByLogicalColour x,
getMaybeEnPassantAbscissa :: Maybe (State.EnPassantAbscissa.EnPassantAbscissa x)
} deriving Eq
instance (
Enum x,
Enum y,
Ord x,
Ord y
) => Ord (Position x y) where
{-# SPECIALISE instance Ord (Position T.X T.Y) #-}
position@MkPosition {
getNextLogicalColour = nextLogicalColour,
getMaybePieceByCoordinates = maybePieceByCoordinates
} `compare` position'@MkPosition {
getNextLogicalColour = nextLogicalColour',
getMaybePieceByCoordinates = maybePieceByCoordinates'
} = (
nextLogicalColour,
maybePieceByCoordinates,
getCastleableRooksByLogicalColour position,
getMaybeEnPassantAbscissa position
) `compare` (
nextLogicalColour',
maybePieceByCoordinates',
getCastleableRooksByLogicalColour position',
getMaybeEnPassantAbscissa position'
)
instance (
Control.DeepSeq.NFData x,
Control.DeepSeq.NFData y
) => Control.DeepSeq.NFData (Position x y) where
rnf MkPosition {
getNextLogicalColour = nextLogicalColour,
getMaybePieceByCoordinates = maybePieceByCoordinates,
getCastleableRooksByLogicalColour = castleableRooksByLogicalColour,
getMaybeEnPassantAbscissa = maybeEnPassantAbscissa
} = Control.DeepSeq.rnf (nextLogicalColour, maybePieceByCoordinates, castleableRooksByLogicalColour, maybeEnPassantAbscissa)
instance (
Enum x,
Enum y,
Ord x,
Ord y
) => Property.Reflectable.ReflectableOnX (Position x y) where
reflectOnX position@MkPosition {
getNextLogicalColour = nextLogicalColour,
getMaybePieceByCoordinates = maybePieceByCoordinates,
getCastleableRooksByLogicalColour = castleableRooksByLogicalColour
} = position {
getNextLogicalColour = Property.Opposable.getOpposite nextLogicalColour,
getMaybePieceByCoordinates = Property.Reflectable.reflectOnX maybePieceByCoordinates,
getCastleableRooksByLogicalColour = Property.Reflectable.reflectOnX castleableRooksByLogicalColour
}
instance (Data.Array.IArray.Ix x, Enum x, Enum y, Ord y) => Component.Zobrist.Hashable2D Position x y {-CAVEAT: FlexibleInstances, MultiParamTypeClasses-} where
listRandoms2D MkPosition {
getNextLogicalColour = nextLogicalColour,
getMaybePieceByCoordinates = maybePieceByCoordinates,
getCastleableRooksByLogicalColour = castleableRooksByLogicalColour,
getMaybeEnPassantAbscissa = maybeEnPassantAbscissa
} zobrist = (
if Attribute.LogicalColour.isBlack nextLogicalColour
then (Component.Zobrist.getRandomForBlacksMove zobrist :)
else id
) . Data.Maybe.maybe id (
(++) . (`Component.Zobrist.listRandoms1D` zobrist)
) maybeEnPassantAbscissa $ Component.Zobrist.listRandoms1D castleableRooksByLogicalColour zobrist ++ Component.Zobrist.listRandoms2D maybePieceByCoordinates zobrist
-- | Constructor.
mkPosition :: (
Enum x,
Enum y,
Ord x,
Ord y
)
=> Attribute.LogicalColour.LogicalColour -- ^ The logical colour of the next player to move.
-> State.MaybePieceByCoordinates.MaybePieceByCoordinates x y
-> State.CastleableRooksByLogicalColour.CastleableRooksByLogicalColour x
-> Maybe (Component.Turn.Turn x y) -- ^ The last /turn/ made.
-> Position x y
mkPosition nextLogicalColour maybePieceByCoordinates castleableRooksByLogicalColour maybeLastTurn = MkPosition {
getNextLogicalColour = nextLogicalColour,
getMaybePieceByCoordinates = maybePieceByCoordinates, -- N.B.: one could have used 'State.CoordinatesByRankByLogicalColour.CoordinatesByRankByLogicalColour', except that the coordinates have an undefined order.
getCastleableRooksByLogicalColour = castleableRooksByLogicalColour,
getMaybeEnPassantAbscissa = maybeLastTurn >>= State.EnPassantAbscissa.mkMaybeEnPassantAbscissa nextLogicalColour maybePieceByCoordinates
}