xchess/lib/piece-set.js

Chess Engine

export {PieceSet}

import {Piece} from './piece.js'
import {Weight, Advantage, PiecesStat} from './piece-stat.js'
import {IS_EMPTY, IS_STRING, IS_ITERABLE} from './types.js'
import {INVALID_PIECE_LIST} from './errors.js'

class PieceSet extends Set {

	add(piece){
		super.add(Piece.from(piece));
	}

	#setAsList(pieces){
		const pieceList = [];
		for(const piece of pieces)
			pieceList.push(Piece.from(piece));
		this.clear();
		for(const piece of pieceList)
			this.add(piece);
	}

	setAll(pieceList){
		if(IS_EMPTY(pieceList))
			this.clear();
		else if(IS_STRING(pieceList))
			this.fen = pieceList;
		else if(IS_ITERABLE(pieceList))
			this.#setAsList(pieceList);
		else
			throw INVALID_PIECE_LIST(pieceList);
	}

	// Stat

	get weight(){
		return Weight(this);
	}

	advantage(color){
		return Advantage(this, color);
	}

	stat(){
		return PiecesStat(this);
	}

	// I/O

	get fen(){
		const fen = [];
		for(const piece of this)
			fen.push(piece.fen);
		return fen.join('');
	}

	set fen(fen){
		this.#setAsList(String(fen));
	}

	toString(){
		return this.fen;
	}
}