Struct alcibiades::MoveDigest

pub struct MoveDigest(_);

Encodes the minimum needed information that unambiguously describes a move.

MoveDigest is a u16 number. It is laid out the following way:

  15                                                           0
 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
 | Move  |    Origin square      |   Destination square  | Aux   |
 | type  |       6 bits          |        6 bits         | data  |
 | 2 bits|   |   |   |   |   |   |   |   |   |   |   |   | 2 bits|
 |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
 +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+

There are 4 "move type"s: 0) en-passant capture; 1) pawn promotion; 2) castling; 3) normal move. "Aux data" encodes the type of the promoted piece if the move type is pawn promotion, otherwise it is zero.

Methods

impl MoveDigest

fn invalid() -> MoveDigest

Creates an invalid move digest instance.

The returned instance contains 0. This is sometimes useful in places where any move is required but no is available.

fn move_type(&self) -> MoveType

Returns the move type.

fn orig_square(&self) -> Square

Returns the origin square of the played piece.

fn dest_square(&self) -> Square

Returns the destination square for the played piece.

fn aux_data(&self) -> usize

Returns a value between 0 and 3 representing the auxiliary data.

When the move type is pawn promotion, "aux data" encodes the promoted piece type. For all other move types "aux data" is zero.

Trait Implementations

impl Debug for MoveDigest

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Clone for MoveDigest

fn clone(&self) -> MoveDigest

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for MoveDigest

impl PartialEq for MoveDigest

fn eq(&self, __arg_0: &MoveDigest) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, __arg_0: &MoveDigest) -> bool

This method tests for !=.

impl Eq for MoveDigest