class ExtinctionRules extends ChessRules
{
- initVariables(fen)
+ setOtherVariables(fen)
{
- super.initVariables(fen);
- const V = VariantRules;
+ super.setOtherVariables(fen);
+ const pos = V.ParseFen(fen).position;
+ // NOTE: no need for safety "|| []", because each piece type must be present
+ // (otherwise game is already over!)
this.material =
{
"w":
{
- [V.KING]: 1,
- [V.QUEEN]: 1,
- [V.ROOK]: 2,
- [V.KNIGHT]: 2,
- [V.BISHOP]: 2,
- [V.PAWN]: 8
+ [V.KING]: pos.match(/K/g).length,
+ [V.QUEEN]: pos.match(/Q/g).length,
+ [V.ROOK]: pos.match(/R/g).length,
+ [V.KNIGHT]: pos.match(/N/g).length,
+ [V.BISHOP]: pos.match(/B/g).length,
+ [V.PAWN]: pos.match(/P/g).length
},
"b":
{
- [V.KING]: 1,
- [V.QUEEN]: 1,
- [V.ROOK]: 2,
- [V.KNIGHT]: 2,
- [V.BISHOP]: 2,
- [V.PAWN]: 8
+ [V.KING]: pos.match(/k/g).length,
+ [V.QUEEN]: pos.match(/q/g).length,
+ [V.ROOK]: pos.match(/r/g).length,
+ [V.KNIGHT]: pos.match(/n/g).length,
+ [V.BISHOP]: pos.match(/b/g).length,
+ [V.PAWN]: pos.match(/p/g).length
}
};
}
+ getPotentialPawnMoves([x,y])
+ {
+ let moves = super.getPotentialPawnMoves([x,y]);
+ // Add potential promotions into king
+ const color = this.turn;
+ const shift = (color == "w" ? -1 : 1);
+ const lastRank = (color == "w" ? 0 : V.size.x-1);
+
+ if (x+shift == lastRank)
+ {
+ // Normal move
+ if (this.board[x+shift][y] == V.EMPTY)
+ moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:V.KING}));
+ // Captures
+ if (y>0 && this.board[x+shift][y-1] != V.EMPTY
+ && this.canTake([x,y], [x+shift,y-1]))
+ {
+ moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:color,p:V.KING}));
+ }
+ if (y<V.size.y-1 && this.board[x+shift][y+1] != V.EMPTY
+ && this.canTake([x,y], [x+shift,y+1]))
+ {
+ moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:color,p:V.KING}));
+ }
+ }
+
+ return moves;
+ }
+
// TODO: verify this assertion
atLeastOneMove()
{
return true; //always at least one possible move
}
- underCheck(move)
+ underCheck(color)
{
return false; //there is no check
}
- getCheckSquares(move)
+ getCheckSquares(color)
{
return [];
}
updateVariables(move)
{
super.updateVariables(move);
- if (move.vanish.length==2 && move.appear.length==1)
+ // Treat the promotion case: (not the capture part)
+ if (move.appear[0].p != move.vanish[0].p)
+ {
+ this.material[move.appear[0].c][move.appear[0].p]++;
+ this.material[move.appear[0].c][V.PAWN]--;
+ }
+ if (move.vanish.length==2 && move.appear.length==1) //capture
this.material[move.vanish[1].c][move.vanish[1].p]--;
}
unupdateVariables(move)
{
super.unupdateVariables(move);
+ if (move.appear[0].p != move.vanish[0].p)
+ {
+ this.material[move.appear[0].c][move.appear[0].p]--;
+ this.material[move.appear[0].c][V.PAWN]++;
+ }
if (move.vanish.length==2 && move.appear.length==1)
this.material[move.vanish[1].c][move.vanish[1].p]++;
}
return "*";
}
- return this.checkGameEnd();
+ return this.checkGameEnd(); //NOTE: currently unreachable...
+ }
+
+ checkGameEnd()
+ {
+ return (this.turn == "w" ? "0-1" : "1-0");
}
- // Very negative (resp. positive) if white (reps. black) pieces set is incomplete
evalPosition()
{
- if (this.missAkind())
- return (this.turn=="w"?-1:1) * VariantRules.INFINITY;
+ const color = this.turn;
+ if (Object.keys(this.material[color]).some(
+ p => { return this.material[color][p] == 0; }))
+ {
+ // Very negative (resp. positive) if white (reps. black) pieces set is incomplete
+ return (color=="w"?-1:1) * V.INFINITY;
+ }
return super.evalPosition();
}
}
+
+const VariantRules = ExtinctionRules;