BcmathCalculator.php

<?php



class BcmathCalculator extends Nette\Object implements ICalculator
{

  /** @var int */
	private $scale;



	/**
	 * @param int
	 */
	public function __construct($scale = 0)
	{
		$this->scale = $scale;
	}



	public function getScale()
	{
		return $this->scale;
	}



	/* BASIC OPERATIONS */


	public function add($a, $b)
	{
		return bcadd($a, $b, $this->scale);
	}



	public function subtract($a, $b)
	{
		return bcsub($a, $b, $this->scale);
	}



	public function multiply($a, $b)
	{
		return bcmul($a, $b, $this->scale);
	}



	public function divide($a, $b)
	{
		return bcdiv($a, $b, $this->scale);
	}



	public function power($a, $b)
	{
		return bcpow($a, $b, $this->scale);
	}



	/**
	 * @param string|int|float $number
	 * @return string
	 */
	public function floor($number)
	{
		$result = bcmul($number, '1', 0);
		if ((bccomp($result, '0', 0) == -1) && bccomp($number, $result, 1)) {
			$result = bcsub($result, 1, 0);
		}

		return $result;
	}



	/**
	 * @param string|int|float $number
	 * @return string
	 */
	public function ceil($number)
	{
		$floor = $this->bcfloor($number);

		return bcadd($floor, ceil($this->bcsub($number, $floor)), 0);
	}



	/**
	 * @param string|int|float $number
	 * @param int
	 * @return string
	 */
	public function round($number, $decimals = 0)
	{
		if ($decimals < -1) {
			throw new InvalidArgumentException("Cannot round to negative decimals");
		}

		if ($decimals > 0) {
			$to = bcpow(10, $decimals, 0);
			$number = bcmul($number, $to, $this->scale);
		}

		$floor = $this->floor($number);
		$result = bcadd($floor, round(bcsub($number, $floor)), 0);

		if ($decimals > 0) {
			$result = bcdiv($floor, $to, $decimals);
		}

		return $result;
	}



	/* COMPARISON FUNCTIONS */



	public function max($a, $b)
	{
		return $this->compare($a, $b) == 1 ? $a : $b;
	}



	public function min($a, $b)
	{
		return $this->compare($a, $b) == 1 ? $b : $a;
	}



	public function compare($a, $b)
	{
		return bccomp($a, $b, $this->scale);
	}
}