Struct Setup 

pub struct Setup { /* private fields */ }

A builder type for chess positions.

This type is useful to edit a position without having to ensure it stays legal at every step. It must be validated and converted to a Position using Setup::into_position before generating moves.

Text description

Forsyth-Edwards Notation (FEN) is typically used to describe chess positions as text. eschac uses a slightly different notation, which simply removes the last two fields of the FEN record (i.e. the halfmove clock and the fullmove number) as the Position type does not keep track of those. For example, the starting position is recorded as rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq -.

Display and FromStr are purposely not implemented on Setup as there does not exist a truely canonical format for writing chess positions. The format described above is implemented in from_text_record and to_text_record.

Implementations

impl Setup

pub fn new() -> Self

Creates an empty board, i.e. 8/8/8/8/8/8/8/8 w - -.

pub fn from_text_record(record: &str) -> Result<Self, ParseRecordError>

Reads a position from a text record (see from_ascii_record).

pub fn from_ascii_record(record: &[u8]) -> Result<Self, ParseRecordError>

Reads a position from a text record.

pub fn set(&self, square: Square, piece: Option<Piece>) -> Self

Sets the occupancy of a square.

pub fn set_turn(&self, color: Color) -> Self

Sets the color to play.

pub fn switch_turn(&self) -> Self

Switches the color to play.

pub fn set_castling_rights( &self, color: Color, castle: Castle, value: bool, ) -> Self

Sets the castling rights for the given color and side.

pub fn set_en_passant_target_square(&self, square: Option<Square>) -> Self

Sets the en passant target square.

pub fn mirror(&self) -> Self

Returns the mirror image of the position.

The mirror of a position is the position obtained after reflecting the placement of pieces horizontally, inverting the color of all the pieces, inverting the turn, and reflecting the castling rights as well as the en passant target square.

For example, the mirror image of rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b Kq e3 is rnbqkbnr/pppp1ppp/8/4p3/8/8/PPPPPPPP/RNBQKBNR w Qk e6.

pub fn illegal_reasons(&self) -> IllegalPositionReasons

Checks for the validity of the position, returning a set of potential reasons.

pub fn into_position(self) -> Result<Position, IllegalPosition>

Tries to convert the position into the Position type.

Some unreachable positions are rejected, see IllegalPositionReason for details.

pub unsafe fn into_position_unchecked(self) -> Position

Converts the position into the Position type without checking if it is valid.

Safety: if the position is not valid, using it might cause undefined behavior.

pub fn from_bitboards(bitboards: [Bitboard; 5]) -> Option<Self>

Returns the position encoded by the given bitboards, or None if the bitboards are not compatible with the format described in AsSetup::bitboards.

pub unsafe fn from_bitboards_unchecked(bitboards: [Bitboard; 5]) -> Self

Returns the position encoded by the given bitboards, without checking if the format is respected.

Safety: if the bitboards are ill-formed, then using the position obtained from this method might cause undefined behavior.

Trait Implementations

impl AsSetup for Setup

fn as_setup(&self) -> &Setup

fn bitboards(&self) -> [Bitboard; 5]

Returns the inner bitboard representation of the position.

fn get(&self, square: Square) -> Option<Piece>

Returns the piece on the square, if any.

fn turn(&self) -> Color

Returns the color to play.

fn castling_rights(&self, color: Color, castle: Castle) -> bool

Returns true if castling is available for the given color and side.

fn en_passant_target_square(&self) -> Option<Square>

Returns the optional en passant target square.

fn pieces(&self) -> ByColor<ByRole<Bitboard>>

Returns the squares occupied by each type & color of piece.

fn to_text_record(&self) -> String

Returns the text record of the position (see write_text_record).

fn write_text_record<W: Write>(&self, w: &mut W) -> Result

Writes the text record of the position.

impl Clone for Setup

fn clone(&self) -> Setup

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Setup

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for Setup

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Setup

impl Ord for Setup

fn cmp(&self, other: &Setup) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Setup

fn eq(&self, other: &Setup) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Setup

fn partial_cmp(&self, other: &Setup) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for Setup