{-
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@]
* Itemises the ways in which a game may be declared a draw.
* Each reason corresponds to a rule in chess.
-}
module BishBosh.Model.DrawReason(
-- * Types
-- ** Data-types
DrawReason(),
-- * Constants
maximumConsecutiveRepeatablePlies,
maximumConsecutiveRepeatablePositions,
byAgreement,
-- fiftyMoveRule,
seventyFiveMoveRule,
insufficientMaterial,
staleMate,
-- threeFoldRepetition,
fiveFoldRepetition,
range
) where
import qualified BishBosh.Component.Move as Component.Move
import qualified Control.DeepSeq
-- | The ways in which a game can be drawn.
data DrawReason
= ByAgreement -- ^ Both players have agreed to a draw.
| FiftyMoveRule -- ^ A draw can be claimed if fifty consecutive full /move/s have occured without any capture or any @Pawn@ being moved.
| SeventyFiveMoveRule -- ^ Seventy-five consecutive full /move/s have occured without either capture or @Pawn@-movement; .
| InsufficientMaterial -- ^ Neither player as the fire-power to force /check-mate/.
| StaleMate -- ^ The next player hasn't any legal moves, but isn't /in check/.
| ThreeFoldRepetition -- ^ A draw can be claimed if the same /position/ has been reached on any three occasions.
| FiveFoldRepetition -- ^ The same /position/ has been reached on five successive occasions.
deriving (Eq, Read, Show)
instance Control.DeepSeq.NFData DrawReason where
rnf _ = ()
-- | Constant.
byAgreement :: DrawReason
byAgreement = ByAgreement
-- | Constant.
fiftyMoveRule :: DrawReason
fiftyMoveRule = FiftyMoveRule
-- | Constant.
seventyFiveMoveRule :: DrawReason
seventyFiveMoveRule = SeventyFiveMoveRule
-- | Constant.
insufficientMaterial :: DrawReason
insufficientMaterial = InsufficientMaterial
-- | Constant.
staleMate :: DrawReason
staleMate = StaleMate
-- | Constant.
threeFoldRepetition :: DrawReason
threeFoldRepetition = ThreeFoldRepetition
-- | Constant.
fiveFoldRepetition :: DrawReason
fiveFoldRepetition = FiveFoldRepetition
-- | The constant range of possible values.
range :: [DrawReason]
range = [byAgreement, fiftyMoveRule, seventyFiveMoveRule, insufficientMaterial, staleMate, threeFoldRepetition, fiveFoldRepetition]
-- | The number of consecutive plies required to trigger a draw by the seventy-five move rule.
maximumConsecutiveRepeatablePlies :: Component.Move.NMoves
maximumConsecutiveRepeatablePlies = Component.Move.nPliesPerMove * 75
-- | The number of consecutive repeatable positions required for a draw by the five-fold repetition rule.
maximumConsecutiveRepeatablePositions :: Component.Move.NMoves
maximumConsecutiveRepeatablePositions = 5