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Add BigRational::isFiniteDecimal()

This commit is contained in:
Benjamin Morel 2015-06-19 14:10:31 +02:00
parent 9a043bebf4
commit c9a518affc
2 changed files with 95 additions and 0 deletions

View File

@ -241,6 +241,29 @@ class BigRational implements \Serializable
return new BigRational($numerator, $denominator, false);
}
/**
* Returns whether this rational number can be represented as a finite decimal.
*
* @return bool
*/
public function isFiniteDecimal()
{
$denominator = $this->simplified()->denominator;
foreach ([2, 5] as $divisor) {
do {
list ($quotient, $remainder) = $denominator->divideAndRemainder($divisor);
if ($remainderIsZero = $remainder->isZero()) {
$denominator = $quotient;
}
}
while ($remainderIsZero);
}
return $denominator->isEqualTo(1);
}
/**
* Compares this number to the given one.
*

View File

@ -336,6 +336,78 @@ class BigRationalTest extends AbstractTestCase
];
}
/**
* @dataProvider providerIsFiniteDecimal
*
* @param string $rational The rational number to test.
* @param bool $isFiniteDecimal Whether the number can be represented as a finite decimal number.
*/
public function testIsFiniteDecimal($rational, $isFiniteDecimal)
{
$this->assertSame($isFiniteDecimal, BigRational::parse($rational)->isFiniteDecimal());
}
/**
* @return array
*/
public function providerIsFiniteDecimal()
{
return [
['0', true],
['1', true],
['1/2', true],
['2/2', true],
['3/2', true],
['1/3', false],
['2/3', false],
['3/3', true],
['4/3', false],
['1/4', true],
['2/4', true],
['1/5', true],
['2/5', true],
['1/6', false],
['2/6', false],
['3/6', true],
['4/6', false],
['5/6', false],
['6/6', true],
['7/6', false],
['1/7', false],
['2/7', false],
['6/7', false],
['7/7', true],
['8/7', false],
['1/8', true],
['7/8', true],
['1/9', false],
['8/9', false],
['9/9', true],
['10/9', false],
['17/9', false],
['18/9', true],
['19/9', false],
['8/360', false],
['9/360', true],
['10/360', false],
['17/360', false],
['18/360', true],
['19/360', false],
['438002367448868006942618029488152554057431119072727/9', true],
['438002367448868006942618029488152554057431119072728/9', false],
['1278347892548908779/181664161764972047166111224214546382427215576171875', true],
['1278347892548908779/363328323529944094332222448429092764854431152343750', true],
['1278347892548908778/363328323529944094332222448429092764854431152343750', false],
['1278347892548908779/363328323529944094332222448429092764854431152343751', false],
['1274512848871262052662/181119169279677131024612890541902743279933929443359375', false],
['1274512848871262052663/181119169279677131024612890541902743279933929443359375', true],
['1274512848871262052664/181119169279677131024612890541902743279933929443359375', false],
];
}
/**
* @dataProvider providerCompareTo
*