com.saxonica.hof
Class AbstractFunctionItem

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

All Implemented Interfaces:

Serializable, PullEvent, FunctionItem, Item, ValueRepresentation

Direct Known Subclasses:

CoercedFunction, CurriedFunction, FirstClassFunction, UserFunctionItem

public abstract class AbstractFunctionItem
extends Object
implements FunctionItem

Abstract superclass (and factory class) for implementations of FunctionItem

See Also:

Serialized Form

Field Summary

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

EMPTY_VALUE_ARRAY

Constructor Summary

AbstractFunctionItem()

Method Summary

static AbstractFunctionItem	bind(StructuredQName functionName, int arity, StaticContext env) Factory method to create a function item representing a function item literal
FunctionItem	curry(int arg, ValueRepresentation value) Curry a function by binding one of its arguments
void	explain(ExpressionPresenter out)
String	getStringValue() Get the string value of the function item
CharSequence	getStringValueCS() Get the string value of the function item
SequenceIterator	getTypedValue() Get the typed value of the item.
void	optimize(ExpressionVisitor visitor, ItemType contextItemType) Optimize the function (may modify it)
void	typeCheck(ExpressionVisitor visitor, ItemType contextItemType) Type check the function (may modify it by adding code for converting the arguments)

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.FunctionItem

getArity, getFunctionItemType, getFunctionName, invoke

Constructor Detail

AbstractFunctionItem

public AbstractFunctionItem()

Method Detail

getStringValue

public String getStringValue()

Get the string value of the function item

Specified by:

getStringValue in interface Item

Specified by:

getStringValue in interface ValueRepresentation

Returns:

the string value of the item

Throws:

UnsupportedOperationException - (the string value of a function item is not defined)

See Also:

Item.getStringValueCS()

getStringValueCS

public CharSequence getStringValueCS()

Get the string value of the function item

Specified by:

getStringValueCS in interface Item

Specified by:

getStringValueCS in interface ValueRepresentation

Returns:

the string value of the item

Throws:

UnsupportedOperationException - (the string value of a function item is not defined)

See Also:

Item.getStringValue()

getTypedValue

public SequenceIterator getTypedValue()
                               throws XPathException

Get the typed value of the item.

Specified by:

getTypedValue in interface Item

Returns:

an iterator over the items in the typed value of the node or atomic value. The items returned by this iterator will always be atomic values.

Throws:

XPathException - (always) - a function item cannot be atomized

typeCheck

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

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

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,
                     ItemType contextItemType)
              throws XPathException

Optimize the function (may modify it)

Parameters:

visitor - the expression visitor, supplies context information

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

Throws:

XPathException

curry

public FunctionItem curry(int arg,
                          ValueRepresentation value)
                   throws XPathException

Curry a function by binding one of its arguments

Specified by:

curry in interface FunctionItem

Parameters:

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

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

Throws:

XPathException

bind

public static AbstractFunctionItem bind(StructuredQName functionName,
                                        int arity,
                                        StaticContext env)
                                 throws XPathException

Factory method to create a function item representing a function item literal

Parameters:

functionName - the name of the function to be called

arity - the arity of the function

env - the static context of the function item literal

Returns:

the constructed function item

Throws:

XPathException - for example if there is no function with the specified name and arity in the static context

explain

public void explain(ExpressionPresenter out)