net.sf.saxon.om
Interface FunctionItem

All Superinterfaces:

Item, PullEvent, Serializable, ValueRepresentation

All Known Implementing Classes:

AbstractFunctionItem, CoercedFunction, CurriedFunction, FirstClassFunction, UserFunctionItem

public interface FunctionItem
extends Item, Serializable

XQuery 1.1 introduces a third kind of item, beyond nodes and atomic values: the function item. Function items implement this marker interface. The actual implementation class is in Saxon-PE and Saxon-EE only.

Field Summary

Fields inherited from interface net.sf.saxon.om.ValueRepresentation

EMPTY_VALUE_ARRAY

Method Summary

FunctionItem	curry(int arg, ValueRepresentation value) Curry a function by binding one of its arguments
int	getArity() Get the arity of the function
FunctionItemType	getFunctionItemType() Get the item type of the function item
StructuredQName	getFunctionName() Get the name of the function, or null if it is anonymous
SequenceIterator	invoke(SequenceIterator[] args, XPathContext context) Invoke the function

Methods inherited from interface net.sf.saxon.om.Item

getStringValue, getStringValueCS, getTypedValue

Method Detail

getFunctionItemType

FunctionItemType getFunctionItemType()

Get the item type of the function item

Returns:

the function item's type

getFunctionName

StructuredQName getFunctionName()

Get the name of the function, or null if it is anonymous

Returns:

the function name, or null for an anonymous inline function

getArity

int getArity()

Get the arity of the function

Returns:

the number of arguments in the function signature

invoke

SequenceIterator invoke(SequenceIterator[] args,
                        XPathContext context)
                        throws XPathException

Invoke the function

Parameters:

args - the actual arguments to be supplied

context - the XPath dynamic evaluation context

Returns:

the result of invoking the function

Throws:

XPathException

curry

FunctionItem curry(int arg,
                   ValueRepresentation value)
                   throws XPathException

Curry a function by binding one of its arguments

Parameters:

arg - the argument to be found (1-based)

value - the value to which the argument is to be bound

Throws:

XPathException