/**
* Parses a bracketted expression.
*
* @param Constraint $constraint
* @return void
* @throws SparqlParserException
*/
protected function parseBrackettedExpression(&$constraint)
{
$open = 1;
$exp = "";
$this->_fastForward();
while ($open != 0 && current($this->tokens) != false) {
switch (current($this->tokens)) {
case "(":
$open++;
$exp = $exp . current($this->tokens);
break;
case ")":
$open--;
if ($open != 0) {
$exp = $exp . current($this->tokens);
}
break;
case false:
throw new SparqlParserException("Unexpected end of query.", null, key($this->tokens));
default:
$exp = $exp . current($this->tokens);
break;
}
next($this->tokens);
}
$constraint->addExpression($exp);
}
