com.saxonica.hof
Class UserFunctionItem

java.lang.Object
  com.saxonica.hof.AbstractFunctionItem
      com.saxonica.hof.UserFunctionItem

All Implemented Interfaces:

Serializable, PullEvent, FunctionItem, Item, ValueRepresentation

Direct Known Subclasses:

InlineFunctionWithExternals

public class UserFunctionItem
extends AbstractFunctionItem

A UserFunctionItem is a function item representing a call on a user-defined function. It is typically created as a result of the expression local:f#1 where local:f is a user-defined function. The implementation is a wrapper around a UserFunctionCall representing a call on the specified function.

See Also:

Serialized Form

Field Summary

protected UserFunctionCall

target

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

EMPTY_VALUE_ARRAY

Constructor Summary

UserFunctionItem(UserFunctionCall target)

Method Summary

void	explain(ExpressionPresenter out)
int	getArity() Get the arity of the function
FunctionItemType	getFunctionItemType() Determine the item type of the items in the value
StructuredQName	getFunctionName() Get the name of the function
ValueRepresentation	invoke(ValueRepresentation[] args, XPathContext context) Invoke the function
void	typeCheck(ExpressionVisitor visitor, ItemType contextItemType) Type check the function (may modify it by adding code for converting the arguments)

Methods inherited from class com.saxonica.hof.AbstractFunctionItem

bind, curry, getStringValue, getStringValueCS, getTypedValue, optimize

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

target

protected UserFunctionCall target

Constructor Detail

UserFunctionItem

public UserFunctionItem(UserFunctionCall target)

Method Detail

getArity

public int getArity()

Get the arity of the function

Returns:

the number of arguments

getFunctionName

public StructuredQName getFunctionName()

Get the name of the function

Returns:

the name of the function, if it has a name, or null otherwise

getFunctionItemType

public FunctionItemType getFunctionItemType()

Determine the item type of the items in the value

Returns:

the function item type

typeCheck

public void typeCheck(ExpressionVisitor visitor,
                      ItemType contextItemType)
               throws XPathException

Type check the function (may modify it by adding code for converting the arguments)

Overrides:

typeCheck in class AbstractFunctionItem

Parameters:

visitor - the expression visitor, supplies context information

contextItemType - the context item type at the point where the function definition appears

Throws:

XPathException

invoke

public ValueRepresentation invoke(ValueRepresentation[] 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

explain

public void explain(ExpressionPresenter out)

Overrides:

explain in class AbstractFunctionItem