/**
* @param string $logical
* @param array $expressions <ExpressionInterface>
*
* @throws ExpressionException
*/
public function __construct($logical, array $expressions)
{
$this->logical = $logical;
foreach ($expressions as $expr) {
if (!$expr instanceof ExpressionInterface) {
throw ExpressionException::notInstanceOfExpression();
}
$this->_expression[] = $expr;
}
}
/**
* Dispatch walking an expression to the appropriate handler.
*
* @param ExpressionInterface $expr
*
* @return mixed
*
* @throws ExpressionException
*/
public function dispatch(ExpressionInterface $expr)
{
switch (true) {
case $expr instanceof Comparison:
return $this->walkComparison($expr);
case $expr instanceof CompositeExpression:
return $this->walkCompositeExpression($expr);
default:
throw ExpressionException::unknownExpression($expr);
}
}
/**
* Convert a composite expression into the target query language output.
*
* @param CompositeExpression $expr
*
* @return mixed
*
* @throws ExpressionException
*/
public function walkCompositeExpression(CompositeExpression $expr)
{
$expressionList = array();
foreach ($expr->getExpressionList() as $expression) {
$expressionList[] = $this->dispatch($expression);
}
switch ($expr->getLogical()) {
case CompositeExpression::LOGICAL_AND:
return $this->andExpression($expressionList);
case CompositeExpression::LOGICAL_OR:
return $this->orExpression($expressionList);
default:
throw ExpressionException::unknownCompositeLogical($expr->getLogical());
}
}
