{-
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/ may be considered to have converged, since they now have equal opportunity.
* 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.Colour.LogicalColour as Colour.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.StateProperty.Hashable as StateProperty.Hashable
import qualified Control.DeepSeq
-- | The state of the game, without regard to how it arrived there.
data Position = MkPosition {
getNextLogicalColour :: Colour.LogicalColour.LogicalColour, -- ^ The next player to move.
getMaybePieceByCoordinates :: State.MaybePieceByCoordinates.MaybePieceByCoordinates,
getCastleableRooksByLogicalColour :: State.CastleableRooksByLogicalColour.CastleableRooksByLogicalColour,
getMaybeEnPassantAbscissa :: Maybe State.EnPassantAbscissa.EnPassantAbscissa
} deriving Eq
instance Ord Position where
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 Position where
rnf MkPosition {
getNextLogicalColour = nextLogicalColour,
getMaybePieceByCoordinates = maybePieceByCoordinates,
getCastleableRooksByLogicalColour = castleableRooksByLogicalColour,
getMaybeEnPassantAbscissa = maybeEnPassantAbscissa
} = Control.DeepSeq.rnf (nextLogicalColour, maybePieceByCoordinates, castleableRooksByLogicalColour, maybeEnPassantAbscissa)
instance Property.Reflectable.ReflectableOnX Position 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 StateProperty.Hashable.Hashable Position where
listRandoms zobrist MkPosition {
getNextLogicalColour = nextLogicalColour,
getMaybePieceByCoordinates = maybePieceByCoordinates,
getCastleableRooksByLogicalColour = castleableRooksByLogicalColour,
getMaybeEnPassantAbscissa = maybeEnPassantAbscissa
} = (
if Colour.LogicalColour.isBlack nextLogicalColour
then (Component.Zobrist.getRandomForBlacksMove zobrist :)
else id
) $ StateProperty.Hashable.listRandoms zobrist (maybeEnPassantAbscissa, castleableRooksByLogicalColour, maybePieceByCoordinates)
-- | Constructor.
mkPosition
:: Colour.LogicalColour.LogicalColour -- ^ The logical colour of the next player to move.
-> State.MaybePieceByCoordinates.MaybePieceByCoordinates
-> State.CastleableRooksByLogicalColour.CastleableRooksByLogicalColour
-> Maybe Component.Turn.Turn -- ^ The last /turn/ made.
-> Position
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
}