No method to pop a move from MoveHistory

[alex-hunter3]

I'm trying to implement a bot with this library powering the game. However, instead of deep copying the board while constructing the tree there should be a method to pop the last move off the MoveHistory as it would be a lot faster than copying the board for each node of the minimax tree.

Is there a function that exists currently?

[LouieMartin]

This is how I do it:

func negamax(depth int, alpha float64, beta float64, position *chess.Position) float64 {
	depth = int(math.Max(float64(depth), 0))

	if depth == 0 {
		return evaluate(position)
	}

	moves := position.ValidMoves()

	for _, move := range moves {
		new_position := position.Update(move)
		evaluation := -negamax(
			depth-1,
			-beta,
			-alpha,
			new_position,
		)

		if evaluation >= beta {
			return beta
		}

		alpha = math.Max(evaluation, alpha)
	}

	return alpha
}