A type representing the type of a chess piece, i.e. pawn, knight, bishop, etc. It's essentially a chess piece without information about its color.

Value representing a pawn.

Value representing a knight.

Value representing a bishop.

Value representing a rook.

Value representing a queen.

Value representing a king.

List of all piece types.

all =
    [ pawn, knight, bishop, rook, queen, king ]

List of all piece types to which a pawn can promote.

promotionPieces =
    [ queen, rook, bishop, knight ]

Tries to convert a character to a PieceType. Accepts both uppercase and lowercase letters; returns Nothing if the character is not one of the piece letters used in English algebraic notation.

fromChar 'P' == Just pawn


fromChar 'r' == Just rook


fromChar 'x' == Nothing

Tries to convert a string to a PieceType, based on the first character in the string. Accepts both uppercase and lowercase letters; returns Nothing if the character is not one of the piece letters used in English algebraic notation.

fromString "k" == Just king


fromString "Qa4+" == Just queen


fromString "x" == Nothing

Converts a PieceType to the corresponding character used in English algebraic notation.

toChar pawn == 'P'


toChar knight == 'N'


toChar bishop == 'B'


toChar rook == 'R'


toChar queen == 'Q'


toChar king == 'K'

Converts a PieceType to the a single-character string containing the corresponding piece letter used in English algebraic notation.

toString pawn == "P"


toString knight == "N"


toString bishop == "B"


toString rook == "R"


toString queen == "Q"


toString king == "K"