com.saxonica.functions.hof

Class UserFunctionItem

java.lang.Object

net.sf.saxon.om.AbstractItem

com.saxonica.functions.hof.AbstractFunctionItem

com.saxonica.functions.hof.UserFunctionItem

All Implemented Interfaces:

PullEvent, Callable, FunctionItem, GroundedValue, Item, Sequence

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.

Field Summary

Fields

Modifier and Type	Field and Description
protected UserFunctionCall	target

Constructor Summary

Constructors

Constructor and Description
UserFunctionItem(UserFunctionCall target)

Method Summary

Methods

Modifier and Type	Method and Description
Sequence	call(XPathContext context, Sequence[] args) Invoke the function
void	explain(ExpressionPresenter out)
int	getArity() Get the arity of the function
FunctionItemType	getFunctionItemType(TypeHierarchy th) Determine the item type of the items in the value
StructuredQName	getFunctionName() Get the name of the function
UserFunctionCall	getUserFunctionCall() Get the underlying UserFunctionCall
void	optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) Optimize the function (may modify it)
void	simplify(ExpressionVisitor visitor)
void	typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) Type check the function (may modify it by adding code for converting the arguments)

Methods inherited from class com.saxonica.functions.hof.AbstractFunctionItem

deepEquals, effectiveBooleanValue, getStringValue, getStringValueCS, getTypedValue

Methods inherited from class net.sf.saxon.om.AbstractItem

getLength, head, itemAt, iterate, reduce, subsequence

Methods inherited from class java.lang.Object

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

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

getLength, itemAt, reduce, subsequence

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

head, iterate

Field Detail

target

protected UserFunctionCall target

Constructor Detail

UserFunctionItem

public UserFunctionItem(UserFunctionCall target)

Method Detail

getUserFunctionCall

public UserFunctionCall getUserFunctionCall()

Get the underlying UserFunctionCall

Returns:

the UserFunctionCall represented by this function item

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(TypeHierarchy th)

Determine the item type of the items in the value

Parameters:

th -

Returns:

the function item type

simplify

public void simplify(ExpressionVisitor visitor)
              throws XPathException

Overrides:

simplify in class AbstractFunctionItem

Throws:

XPathException

typeCheck

public void typeCheck(ExpressionVisitor visitor,
             ExpressionVisitor.ContextItemType 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

optimize

public void optimize(ExpressionVisitor visitor,
            ExpressionVisitor.ContextItemType contextItemType)
              throws XPathException

Optimize the function (may modify it)

Overrides:

optimize 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

call

public Sequence call(XPathContext context,
            Sequence[] args)
              throws XPathException

Invoke the function

Parameters:

context - the XPath dynamic evaluation context

args - the actual arguments to be supplied

Returns:

the result of invoking the function

Throws:

XPathException

explain

public void explain(ExpressionPresenter out)

Overrides:

explain in class AbstractFunctionItem