/**
* Process the Repeat operator.
*
* Note: NULL values are simply ignored. If all sub-expressions are NULL, NULL is
* returned.
*
* @return \qtism\runtime\common\OrderedContainer An ordered container filled sequentially by evaluating each sub-expressions, repeated a 'numberRepeats' of times. NULL is returned if all sub-expressions are NULL or numberRepeats < 1.
* @throws \qtism\runtime\expressions\operators\OperatorProcessingException
*/
public function process()
{
$operands = $this->getOperands();
// get the value of numberRepeats
$expression = $this->getExpression();
$numberRepeats = $expression->getNumberRepeats();
if (gettype($numberRepeats) === 'string') {
// Variable reference found.
$state = $this->getState();
$varName = Utils::sanitizeVariableRef($numberRepeats);
$varValue = $state[$varName];
if (is_null($varValue) === true) {
$msg = "The variable with name '{$varName}' could not be resolved.";
throw new OperatorProcessingException($msg, $this);
} elseif ($varValue instanceof Integer) {
$msg = "The variable with name '{$varName}' is not an integer value.";
throw new OperatorProcessingException($msg, $this);
}
$numberRepeats = $varValue->getValue();
}
if ($numberRepeats < 1) {
return null;
}
$result = null;
for ($i = 0; $i < $numberRepeats; $i++) {
$refType = null;
foreach ($operands as $operand) {
// If null, ignore
if (is_null($operand) || $operand instanceof Container && $operand->isNull()) {
continue;
}
// Check cardinality.
if ($operand->getCardinality() !== Cardinality::SINGLE && $operand->getCardinality() !== Cardinality::ORDERED) {
$msg = "The Repeat operator only accepts operands with a single or ordered cardinality.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::WRONG_CARDINALITY);
}
// Check baseType.
$currentType = RuntimeUtils::inferBaseType($operand);
if ($refType !== null && $currentType !== $refType) {
$msg = "The Repeat operator only accepts operands with the same baseType.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::WRONG_BASETYPE);
} elseif (is_null($result)) {
$refType = $currentType;
$result = new OrderedContainer($refType);
}
// Okay we are good...
$operandCardinality = RuntimeUtils::inferCardinality($operand);
if ($operandCardinality !== Cardinality::ORDERED) {
$operand = new OrderedContainer($currentType, array($operand));
}
foreach ($operand as $o) {
$result[] = $o instanceof QtiDatatype ? clone $o : $o;
}
}
}
if (isset($result) && $result->isNull() !== true) {
return $result;
} else {
return null;
}
}
/**
* Process the RoundTo operator.
*
* An OperatorProcessingException will be thrown if:
*
* * The given operand is not a numeric value.
* * The cardinality of the operand is not single.
* * The value of the 'figures' attribute comes from a templateVariable which does not exist or is not numeric or null.
*
* @return null|float A single float with the value nearest to that of the expression's value or NULL if the sub-expression is NaN.
* @throws \qtism\runtime\expressions\operators\OperatorProcessingException
*/
public function process()
{
$operands = $this->getOperands();
$state = $this->getState();
$operand = $operands[0];
// If the value is null, return null.
if ($operands->containsNull()) {
return null;
}
if (!$operands->exclusivelySingle()) {
$msg = "The RoundTo operator accepts 1 operand with single cardinality.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::WRONG_CARDINALITY);
}
// Accept only numerical operands.
if (!$operands->exclusivelyNumeric()) {
$msg = "The RoundTo operand accepts 1 operand with numerical baseType.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::WRONG_BASETYPE);
}
// As per QTI 2.1 spec...
if (is_nan($operand->getValue())) {
return null;
} elseif (is_infinite($operand->getValue())) {
return $operand;
}
$roundingMode = $this->getExpression()->getRoundingMode();
$figures = $this->getExpression()->getFigures();
if (gettype($figures) === 'string') {
// try to recover the value from the state.
$figuresIdentifier = Utils::sanitizeVariableRef($figures);
$figures = $state[$figuresIdentifier];
if (is_null($figures)) {
$msg = "The variable '{$figuresIdentifier}' used to set up the 'figures' attribute is null or nonexisting.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::NONEXISTENT_VARIABLE);
} elseif (!$figures instanceof Integer) {
$msg = "The variable '{$figuresIdentifier}' used to set up the 'figures' attribute is not an integer.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::WRONG_VARIABLE_BASETYPE);
}
$figures = $figures->getValue();
}
if ($roundingMode === RoundingMode::SIGNIFICANT_FIGURES) {
if ($figures <= 0) {
// As per QTI 2.1 spec.
$msg = "The 'figures' attribute must be a non-zero positive integer when mode 'significantFigures' is used, '{$figures}' given.";
throw new OperatorProcessingException($msg, $this, OperatorProcessingException::LOGIC_ERROR);
}
if ($operand->getValue() == 0) {
return new Float(0.0);
}
$d = ceil(log10($operand->getValue() < 0 ? -$operand->getValue() : $operand->getValue()));
$power = $figures - intval($d);
$magnitude = pow(10, $power);
$shifted = round($operand->getValue() * $magnitude);
return new Float(floatval($shifted / $magnitude));
} else {
// As per QTI 2.1 spec.
if ($figures < 0) {
$msg = "The 'figures' attribute must be a integer greater than or equal to zero when mode 'decimalPlaces' is used, '{$figures}' given.";
throw new OperatorProcessingException($msg, $this);
}
return new Float(round($operand->getValue(), $figures));
}
}
