net.sf.saxon.functions
Class Subsequence

java.lang.Object
  net.sf.saxon.expr.ComputedExpression
      net.sf.saxon.expr.FunctionCall
          net.sf.saxon.functions.SystemFunction
              net.sf.saxon.functions.Subsequence

All Implemented Interfaces:

Container, Expression, InstructionInfoProvider, java.io.Serializable, javax.xml.transform.SourceLocator

public class Subsequence

extends SystemFunction

Implements the XPath 2.0 subsequence() function

See Also:

Serialized Form

Field Summary

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

operation

Fields inherited from class net.sf.saxon.expr.FunctionCall

argument

Fields inherited from class net.sf.saxon.expr.ComputedExpression

locationId, staticProperties

Fields inherited from interface net.sf.saxon.expr.Expression

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

Subsequence()

Method Summary

int	computeSpecialProperties() Get the static properties of this expression (other than its type).
ItemType	getItemType(TypeHierarchy th) Determine the data type of the items in the sequence
SequenceIterator	iterate(XPathContext context) Evaluate the function to return an iteration of selected nodes.

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

addContextDocumentArgument, checkArguments, computeCardinality, display, getDetails, getErrorCodeForTypeErrors, getRequiredType, main, makeSystemFunction, setDetails, useContextItemAsDefault

Methods inherited from class net.sf.saxon.expr.FunctionCall

checkArgumentCount, getDisplayName, getFunctionNameCode, getNumberOfArguments, iterateSubExpressions, optimize, preEvaluate, promote, setArguments, setFunctionNameCode, simplify, simplifyArguments, typeCheck

Methods inherited from class net.sf.saxon.expr.ComputedExpression

adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, suppressValidation, typeError, typeError

Methods inherited from class java.lang.Object

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

Constructor Detail

Subsequence

public Subsequence()

Method Detail

getItemType

public ItemType getItemType(TypeHierarchy th)

Determine the data type of the items in the sequence

Specified by:

getItemType in interface Expression

Overrides:

getItemType in class SystemFunction

Parameters:

th -

Returns:

the type of the argument

computeSpecialProperties

public int computeSpecialProperties()

Get the static properties of this expression (other than its type). The result is bit-significant. These properties are used for optimizations. In general, if property bit is set, it is true, but if it is unset, the value is unknown.

Overrides:

computeSpecialProperties in class SystemFunction

iterate

public SequenceIterator iterate(XPathContext context)
                         throws XPathException

Evaluate the function to return an iteration of selected nodes.

Specified by:

iterate in interface Expression

Overrides:

iterate in class ComputedExpression

Parameters:

context - supplies the context for evaluation

Returns:

a SequenceIterator that can be used to iterate over the result of the expression

Throws:

XPathException - if any dynamic error occurs evaluating the expression