/**
* Process the EqualRounded operator.
*
* @return boolean|null A boolean with a value of true if the two expressions are numerically equal after rounding and false if they are not. If either sub-expression is NULL, the operator results in NULL.
* @throws \qtism\runtime\expressions\operators\OperatorProcessingException
*/
public function process()
{
$operands = $this->getOperands();
if ($operands->containsNull()) {
return null;
}
if ($operands->exclusivelySingle() === false) {
$msg = "The EqualRounded operator only accepts operands with a single cardinality.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::WRONG_CARDINALITY);
}
if ($operands->exclusivelyNumeric() === false) {
$msg = "The EqualRounded operator only accepts operands with an integer or float baseType.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::WRONG_BASETYPE);
}
// delegate the rounding to the RoundTo operator.
$expression = $this->getExpression();
$roundingMode = $expression->getRoundingMode();
$figures = $expression->getFigures();
if (gettype($figures) === 'string') {
// Variable reference to deal with.
$state = $this->getState();
$varName = Utils::sanitizeVariableRef($figures);
$varValue = $state[$varName];
if (is_null($varValue) === true) {
$msg = "The variable with name '{$varName}' could not be resolved.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::NONEXISTENT_VARIABLE);
} elseif (!$varValue instanceof Integer) {
$msg = "The variable with name '{$varName}' is not an integer.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::WRONG_VARIABLE_BASETYPE);
}
$figures = $varValue->getValue();
}
$rounded = new OperandsCollection();
// will contain the rounded operands.
foreach ($operands as $operand) {
$baseType = RuntimeUtils::inferBaseType($operand);
$subExpression = new BaseValue($baseType, $operand);
$roundToExpression = new RoundTo(new ExpressionCollection(array($subExpression)), $figures, $roundingMode);
$roundToProcessor = new RoundToProcessor($roundToExpression, new OperandsCollection(array($operand)));
try {
$rounded[] = $roundToProcessor->process();
} catch (OperatorProcessingException $e) {
$msg = "An error occured while rounding '{$operand}'.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::LOGIC_ERROR, $e);
}
}
return new Boolean($rounded[0]->getValue() == $rounded[1]->getValue());
}
public function testInfinity()
{
$expr = $this->createComponentFromXml('
<roundTo figures="0" roundingMode="decimalPlaces">
<baseValue baseType="float">3.4</baseValue>
</roundTo>
');
$operands = new OperandsCollection(array(new Float(INF)));
$processor = new RoundToProcessor($expr, $operands);
$result = $processor->process();
$this->assertTrue(is_infinite($result->getValue()));
$this->assertTrue(INF === $result->getValue());
$processor->setOperands(new OperandsCollection(array(new Float(-INF))));
$result = $processor->process();
$this->assertTrue(is_infinite($result->getValue()));
$this->assertTrue(-INF === $result->getValue());
}