net.sf.saxon.functions

Class Error

java.lang.Object

net.sf.saxon.om.AbstractItem

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.Error

All Implemented Interfaces:

PullEvent, Callable, Function, GroundedValue, Item, Sequence

public class Error
extends SystemFunction
implements Callable

Implement XPath function fn:error()

Constructor Summary

Constructors

Constructor and Description
Error()

Method Summary

Methods

Modifier and Type	Method and Description
Sequence	call(XPathContext context, Sequence[] arguments) Call the Callable.
Item	error(XPathContext context, QNameValue errorCode, StringValue desc, SequenceIterator errObject)
int	getSpecialProperties(Expression[] arguments) Determine the special properties of this function.
boolean	isVacuousExpression() Determine whether this is a vacuous expression as defined in the XQuery update specification

Methods inherited from class net.sf.saxon.functions.SystemFunction

equals, export, exportAttributes, getArity, getCardinality, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getExpressionCompiler, getFunctionItemType, getFunctionName, getIntegerBounds, getOperandRoles, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, getStaticBaseUriString, getStreamingAdjunct, importAttributes, makeCall, makeFunction, makeFunctionCall, makeOptimizedFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, typeCheckCaller

Methods inherited from class net.sf.saxon.functions.AbstractFunction

atomize, deepEquals, effectiveBooleanValue, getStringValue, getStringValueCS, isArray, isMap, optimize, simplify, typeCheck

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

getLength, head, itemAt, iterate, reduce, subsequence

Methods inherited from class java.lang.Object

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

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

iterate

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

head

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

getLength, head, itemAt, reduce, subsequence

Constructor Detail

Error

public Error()

Method Detail

getSpecialProperties

public int getSpecialProperties(Expression[] arguments)

Description copied from class: SystemFunction

Determine the special properties of this function. The general rule is that a system function call is non-creative if its return type is atomic, or if all its arguments are non-creative. This is overridden for the generate-id() function, which is considered creative if its operand is creative (because the result depends on the identity of the operand)

Overrides:

getSpecialProperties in class SystemFunction

Parameters:

arguments - the actual arguments supplied in a call to the function

isVacuousExpression

public boolean isVacuousExpression()

Determine whether this is a vacuous expression as defined in the XQuery update specification

Returns:

true if this expression is vacuous

error

public Item error(XPathContext context,
         QNameValue errorCode,
         StringValue desc,
         SequenceIterator errObject)
           throws XPathException

Throws:

XPathException

call

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

Description copied from interface: Callable

Call the Callable.

Specified by:

call in interface Callable

Specified by:

call in interface Function

Parameters:

context - the dynamic evaluation context

arguments - the values of the arguments, supplied as Sequences.

Generally it is advisable, if calling iterate() to process a supplied sequence, to call it only once; if the value is required more than once, it should first be converted to a GroundedValue by calling the utility methd SequenceTool.toGroundedValue().

If the expected value is a single item, the item should be obtained by calling Sequence.head(): it cannot be assumed that the item will be passed as an instance of Item or AtomicValue.

It is the caller's responsibility to perform any type conversions required to convert arguments to the type expected by the callee. An exception is where this Callable is explicitly an argument-converting wrapper around the original Callable.

Returns:

the result of the evaluation, in the form of a Sequence. It is the responsibility of the callee to ensure that the type of result conforms to the expected result type.

Throws:

XPathException - if a dynamic error occurs during the evaluation of the expression