net.sf.saxon.functions

Class Id

Implemented Interfaces:
EvaluableItem, InstructionInfoProvider, SequenceIterable, Serializable, SourceLocator

public class Id
extends SystemFunction

The XPath id() function XPath 2.0 version: accepts any sequence as the first parameter; each item in the sequence is taken as an IDREFS value, that is, a space-separated list of ID values. Also accepts an optional second argument to identify the target document, this defaults to the context node.

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.Expression

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD, locationId, staticProperties

Method Summary

PathMap.PathMapNodeSet
addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)
Add a representation of a doc() call or similar function to a PathMap.
void
checkArguments(ExpressionVisitor visitor)
Static analysis: prevent sorting of the argument
int
computeSpecialProperties()
Get the static properties of this expression (other than its type).
static SequenceIterator
getIdMultiple(DocumentInfo doc, SequenceIterator idrefs)
Get an iterator over the nodes that have an id equal to one of the values is a set of whitespace separated strings
static SequenceIterator
getIdSingle(DocumentInfo doc, String idrefs)
Get an iterator over the nodes that have an id equal to one of the values is a whitespace separated string
SequenceIterator
iterate(XPathContext context)
Evaluate the function to return an iteration of selected nodes.
Expression
preEvaluate(ExpressionVisitor visitor)
preEvaluate: this method suppresses compile-time evaluation by doing nothing
Expression
simplify(ExpressionVisitor visitor)
Simplify: add a second implicit argument, the context document

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

addContextDocumentArgument, addDocToPathMap, checkArguments, computeCardinality, computeSpecialProperties, copy, getDetails, getErrorCodeForTypeErrors, getItemType, getRequiredType, makeSystemFunction, optimize, setDetails, useContextItemAsDefault

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

addExternalFunctionCallToPathMap, checkArgumentCount, checkArguments, equals, explain, getArguments, getDisplayName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, optimize, preEvaluate, promote, replaceSubExpression, setArguments, setFunctionName, simplify, simplifyArguments, toString, typeCheck

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

addToPathMap, adoptChildExpression, checkPermittedContents, computeCardinality, computeDependencies, computeSpecialProperties, computeStaticProperties, copy, display, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, explain, explain, findParentOf, getCardinality, getColumnNumber, getConstructType, getContainer, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getItemType, getLineNumber, getLocationId, getLocationProvider, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, iterate, iterateEvents, iterateSubExpressions, markTailFunctionCalls, optimize, process, promote, replaceSubExpression, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, simplify, staticTypeCheck, suppressValidation, toString, typeCheck, typeError

Method Details

addToPathMap

public PathMap.PathMapNodeSet addToPathMap(PathMap pathMap,
                                           PathMap.PathMapNodeSet pathMapNodeSet)
Add a representation of a doc() call or similar function to a PathMap. This is a convenience method called by the addToPathMap() methods for doc(), document(), collection() and similar functions. These all create a new root expression in the path map.
Overrides:
addToPathMap in interface Expression
Parameters:
pathMap - the PathMap to which the expression should be added
pathMapNodeSet -
Returns:
the pathMapNode representing the focus established by this expression, in the case where this expression is the first operand of a path expression or filter expression

checkArguments

public void checkArguments(ExpressionVisitor visitor)
            throws XPathException
Static analysis: prevent sorting of the argument
Overrides:
checkArguments in interface SystemFunction

computeSpecialProperties

public int computeSpecialProperties()
Get the static properties of this expression (other than its type). The result is bit-signficant. 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 interface SystemFunction

getIdMultiple

public static SequenceIterator getIdMultiple(DocumentInfo doc,
                                             SequenceIterator idrefs)
            throws XPathException
Get an iterator over the nodes that have an id equal to one of the values is a set of whitespace separated strings
Parameters:
doc - The document to be searched
idrefs - an iterator over a set of strings each of which is a string containing zero or more whitespace-separated ID values to be found in the document
Returns:
an iterator over the nodes whose ID is one of the specified values
Throws:
XPathException -

getIdSingle

public static SequenceIterator getIdSingle(DocumentInfo doc,
                                           String idrefs)
            throws XPathException
Get an iterator over the nodes that have an id equal to one of the values is a whitespace separated string
Parameters:
doc - The document to be searched
idrefs - a string containing zero or more whitespace-separated ID values to be found in the document
Returns:
an iterator over the nodes whose ID is one of the specified values
Throws:
XPathException -

iterate

public SequenceIterator iterate(XPathContext context)
            throws XPathException
Evaluate the function to return an iteration of selected nodes.
Specified by:
iterate in interface SequenceIterable
Overrides:
iterate in interface Expression

preEvaluate

public Expression preEvaluate(ExpressionVisitor visitor)
preEvaluate: this method suppresses compile-time evaluation by doing nothing
Overrides:
preEvaluate in interface FunctionCall
Parameters:
visitor - an expression visitor

simplify

public Expression simplify(ExpressionVisitor visitor)
            throws XPathException
Simplify: add a second implicit argument, the context document
Overrides:
simplify in interface FunctionCall
Parameters:
visitor - an expression visitor