Litipk\BigNumbers\Decimal::pow PHP Méthode

    public function pow(Decimal $b, $scale = null)
    {
        if ($this->isZero()) {
            if ($b->isPositive()) {
                return Decimal::fromDecimal($this, $scale);
            } else {
                throw new \DomainException("zero can't be powered to zero or negative numbers.");
            }
        } elseif ($b->isZero()) {
            return DecimalConstants::One();
        } else {
            if ($b->isNegative()) {
                return DecimalConstants::One()->div($this->pow($b->additiveInverse()), $scale);
            } elseif ($b->scale == 0) {
                $pow_scale = $scale === null ? max($this->scale, $b->scale) : max($this->scale, $b->scale, $scale);
                return self::fromString(bcpow($this->value, $b->value, $pow_scale + 1), $pow_scale);
            } else {
                if ($this->isPositive()) {
                    $pow_scale = $scale === null ? max($this->scale, $b->scale) : max($this->scale, $b->scale, $scale);
                    $truncated_b = bcadd($b->value, '0', 0);
                    $remaining_b = bcsub($b->value, $truncated_b, $b->scale);
                    $first_pow_approx = bcpow($this->value, $truncated_b, $pow_scale + 1);
                    $intermediate_root = self::innerPowWithLittleExponent($this->value, $remaining_b, $b->scale, $pow_scale + 1);
                    return Decimal::fromString(bcmul($first_pow_approx, $intermediate_root, $pow_scale + 1), $pow_scale);
                } else {
                    // elseif ($this->isNegative())
                    if ($b->isInteger()) {
                        if (preg_match('/^[+\\-]?[0-9]*[02468](\\.0+)?$/', $b->value, $captures) === 1) {
                            // $b is an even number
                            return $this->additiveInverse()->pow($b, $scale);
                        } else {
                            // $b is an odd number
                            return $this->additiveInverse()->pow($b, $scale)->additiveInverse();
                        }
                    }
                    throw new NotImplementedException("Usually negative numbers can't be powered to non integer numbers. " . "The cases where is possible are not implemented.");
                }
            }
        }
    }