/**
* Checks if the value represented by this object is negative
*
* @return bool
*/
public function isNegative()
{
return $this->amount->isNegative();
}
/**
* Counts the number of significative digits of $val.
* Assumes a consistent internal state (without zeros at the end or the start).
*
* @param Decimal $val
* @param Decimal $abs $val->abs()
* @return integer
*/
private static function countSignificativeDigits(Decimal $val, Decimal $abs)
{
return strlen($val->value) - ($abs->comp(DecimalConstants::One()) === -1 ? 2 : max($val->scale, 1)) - ($val->isNegative() ? 1 : 0);
}
/**
* Powers this value to $b
*
* @param Decimal $b exponent
* @param integer $scale
* @return Decimal
*/
public function pow(Decimal $b, $scale = null)
{
if ($b->isPositive()) {
if ($this->isPositive()) {
return $this;
}
// if ($this->isNegative())
if ($b->isInfinite()) {
throw new \DomainException("Negative infinite elevated to infinite is undefined.");
}
if ($b->isInteger()) {
if (preg_match('/^[+\\-]?[0-9]*[02468](\\.0+)?$/', $b->value, $captures) === 1) {
// $b is an even number
return self::$pInf;
} else {
// $b is an odd number
return $this;
// Negative Infinite
}
}
throw new NotImplementedException("See issues #21, #22, #23 and #24 on Github.");
} else {
if ($b->isNegative()) {
return DecimalConstants::Zero();
} else {
if ($b->isZero()) {
throw new \DomainException("Infinite elevated to zero is undefined.");
}
}
}
}
