/**
* Calculate the expression.
*
* @param string $expression
*
* @throws InvalidArgumentException
* @throws LogicException
*
* @return int
*/
public function calculate($expression)
{
// Check for invalid expression.
if (!preg_match('/^([0-9]+[' . $this->operatorsRegexp . '])*[0-9]+$/', $expression)) {
throw new InvalidArgumentException('Invalid expression! Bad characters used.');
}
// If its only a number, then it is the result.
if (is_numeric($expression)) {
return (int) $expression;
}
// Complex expression:
// - split at every operator,
// - store the first part,
// - rerun the method for the second part,
// - do the operation with the two parts
$matches = array();
if (preg_match('/^([0-9]+)([' . $this->operatorsRegexp . '])(.*)/', $expression, $matches)) {
return $this->math->runOperation($matches[2], $matches[1], $this->calculate($matches[3]));
} else {
throw new LogicException('There is no way this could happen! (At least in theory.)');
}
}
/**
* @param string $operator
*
* @dataProvider invalidOperatorDataProvider
* @expectedException \InvalidArgumentException
*/
public function testOperationWithInvalidOperator($operator)
{
$this->math->runOperation($operator, 1, 1);
}