net.sf.saxon.functions
public class Aggregate extends SystemFunction
Field Summary | |
---|---|
static int | AVG |
static int | COUNT |
static int | SUM |
Method Summary | |
---|---|
void | checkArguments(StaticContext env)
Static analysis: prevent sorting of the argument |
static int | count(SequenceIterator iter)
Get the number of items in a sequence identified by a SequenceIterator |
Item | evaluateItem(XPathContext context)
Evaluate the function |
ItemType | getItemType(TypeHierarchy th)
Determine the item type of the value returned by the function |
static boolean | isCountFunction(Expression exp)
Determine whether a given expression is a call to the count() function |
Parameters: iter The SequenceIterator. This method moves the current position of the supplied iterator; if this isn't safe, make a copy of the iterator first by calling getAnother(). The supplied iterator must be positioned before the first item (there must have been no call on next()).
Returns: the number of items in the underlying sequence
Throws: XPathException if a failure occurs reading the input sequence
Parameters: th