/**
* Finds an aggregate.
*
* @param node Parse tree to search
* @return First aggregate function in parse tree, or null if not found
*/
public SqlNode findAgg(SqlNode node) {
try {
node.accept(this);
return null;
} catch (Util.FoundOne e) {
Util.swallow(e, null);
return (SqlNode) e.getNode();
}
}
/**
* Returns whether a given node contains a RexCall with a specified operator
*
* @param operator to look for
* @param node a RexNode tree
*/
public static RexCall findOperatorCall(final SqlOperator operator, RexNode node) {
try {
RexVisitor<Void> visitor =
new RexVisitorImpl<Void>(true) {
public Void visitCall(RexCall call) {
if (call.getOperator().equals(operator)) {
throw new Util.FoundOne(call);
}
return super.visitCall(call);
}
};
node.accept(visitor);
return null;
} catch (Util.FoundOne e) {
Util.swallow(e, null);
return (RexCall) e.getNode();
}
}