com.saxonica.functions.extfn

Class Unindexed

java.lang.Object

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

com.saxonica.functions.extfn.Unindexed

All Implemented Interfaces:

Callable, Function, GroundedValue, Item, Sequence

public class Unindexed
extends SystemFunction

The extension function saxon:unindexed returns the value of its argument unchanged. A static call on saxon:unindexed will generally be optimized away; but if the argument is a filter expression, then it disables the use of indexes to optimize that filter expression. This is useful in cases where indexing would achieve no benefit.

Constructor Summary

Constructors

Constructor and Description
Unindexed()

Method Summary

Modifier and Type	Method and Description
Sequence	call(XPathContext context, Sequence[] arguments) Call the Callable.
Expression	makeOptimizedFunctionCall(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo, Expression... arguments) Allow the function to create an optimized call based on the values of the actual arguments

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

dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getCardinality, getCompilerName, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getIntegerBounds, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getStreamerName, getUniStringArg, hashCode, importAttributes, isSequenceVariadic, isTrustedResultType, makeCall, makeFunction, makeFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, toShortString, toString, typeCheckCaller

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

atomize, deepEquals, effectiveBooleanValue, getAnnotations, getUnicodeStringValue, isArray, isMap, makeNewContext, simplify, typeCheck

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

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

getGenre

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

getLength, getStringValue, head, isStreamed, itemAt, iterate, reduce, subsequence

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

asIterable, concatenate, containsNode, materialize

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

makeRepeatable

Constructor Detail

Unindexed

public Unindexed()

Method Detail

makeOptimizedFunctionCall

public Expression makeOptimizedFunctionCall(ExpressionVisitor visitor,
                                            ContextItemStaticInfo contextInfo,
                                            Expression... arguments)
                                     throws XPathException

Description copied from class: SystemFunction

Allow the function to create an optimized call based on the values of the actual arguments

Overrides:

makeOptimizedFunctionCall in class SystemFunction

Parameters:

visitor - the expression visitor

contextInfo - information about the context item

arguments - the supplied arguments to the function call. Note: modifying the contents of this array should not be attempted, it is likely to have no effect.

Returns:

either a function call on this function, or an expression that delivers the same result, or null indicating that no optimization has taken place

Throws:

XPathException - if an error is detected

call

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

Description copied from interface: Callable

Call the Callable.

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 method 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