Rounding problem inside built-in functions about math

[jkuchar]

Strict explicit rounding is probably the most useful feature of this library. 🥇

[BenMorel]

Hi, this is not a bug, but a feature.

By design, the toBigInteger() method explicitly throws an exception if the current number cannot be converted to a BigInteger without rounding.

Implicicit rounding would create more issues than it would solve.

Your code is not a workaround, it's the proper way to explicitly tell the library that the number needs to be rounded DOWN before converting it!

[ScorpioT1000]

Workaround is:

BigDecimal::of(microtime(true))
                ->multipliedBy('1000')
                ->toScale(0, RoundingMode::DOWN)    
                ->toBigInteger()

But I think the function toBigInteger must do it by itself

[julian-sawicki-skrepr]

Reproducing

Let's create the decimal 12.5.

$bigDecimal = BigDecimal::zero()->plus(100)->dividedBy(8, 2);
var_dump($bigDecimal);exit;

Output:

object(Brick\Math\BigDecimal)#11269 (2) {
  ["value":"Brick\Math\BigDecimal":private]=>
  string(4) "1250"
  ["scale":"Brick\Math\BigDecimal":private]=>
  int(2)
}

Now let's create the error: Rounding is necessary to represent the result of the operation at this scale..

$bigDecimal = BigDecimal::zero()->plus(100)->dividedBy(8, 2);
$int = $bigDecimal->toInt();
var_dump($int);exit;

Now let's fix the error: Rounding is necessary to represent the result of the operation at this scale. by introducing toScale(0, RoundingMode::HALF_UP).

$bigDecimal = BigDecimal::zero()->plus(100)->dividedBy(8, 2);
$int = $bigDecimal->toScale(0, RoundingMode::HALF_UP)->toInt();
var_dump($int);exit;

Output:

int(13)