Idref

java.lang.Object
- net.sf.saxon.expr.Expression
- - net.sf.saxon.expr.FunctionCall
  - - net.sf.saxon.functions.SystemFunction
    - - net.sf.saxon.functions.Idref

All Implemented Interfaces:

java.io.Serializable, javax.xml.transform.SourceLocator, LocationProvider, SaxonLocator, EvaluableItem, SequenceIterable, InstructionInfo, org.xml.sax.Locator
```
public class Idref
extends SystemFunction
```
See Also:

Serialized Form

Field Summary
- Fields inherited from class net.sf.saxon.expr.Expression
  EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
- Fields inherited from class net.sf.saxon.expr.FunctionCall
  argument
- Fields inherited from class net.sf.saxon.functions.SystemFunction
  operation

Constructor Summary

Constructors
Constructor Description

Idref()

Constructors
Constructor	Description
`Idref()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`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)`	Method called during static type checking
`int`	`computeSpecialProperties()`	Get the static properties of this expression (other than its type).
`Expression`	`copy()`	Copy an expression.
`static SequenceIterator`	`getIdrefMultiple(DocumentInfo doc, SequenceIterator keys, XPathContext context)`	Get the result when multiple idref values are supplied.
`SequenceIterator`	`iterate(XPathContext context)`	Enumerate the results of the expression
`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
`Expression`	`typeCheck(ExpressionVisitor visitor, ItemType contextItemType)`	Type-check the expression.

Methods inherited from class net.sf.saxon.expr.Expression
adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, evaluatePendingUpdates, explain, findParentOf, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isUpdatingExpression, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError

Methods inherited from class net.sf.saxon.expr.FunctionCall
addExternalFunctionCallToPathMap, checkArgumentCount, equals, explain, getArguments, getDisplayName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, promote, replaceSubExpression, setArguments, setFunctionName, simplifyArguments, toString

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from class net.sf.saxon.functions.SystemFunction
addContextDocumentArgument, addDocToPathMap, computeCardinality, getDetails, getErrorCodeForTypeErrors, getItemType, getRequiredType, makeSystemFunction, optimize, setDetails, useContextItemAsDefault

- Constructor Detail
  - Idref
```
public Idref()
```
- Method Detail
  - simplify
```
public Expression simplify(ExpressionVisitor visitor)
                    throws XPathException
```
    Simplify: add a second implicit argument, the context document
    
    Overrides:
    
    simplify in class FunctionCall
    
    Parameters:
    
    visitor - an expression visitor
    
    Returns:
    
    the simplified expression
    
    Throws:
    
    XPathException - if an error is discovered during expression rewriting
  - typeCheck
```
public Expression typeCheck(ExpressionVisitor visitor,
                            ItemType contextItemType)
                     throws XPathException
```
    Type-check the expression. This also calls preEvaluate() to evaluate the function if all the arguments are constant; functions that do not require this behavior can override the preEvaluate method.
    
    Overrides:
    
    typeCheck in class FunctionCall
    
    Parameters:
    
    visitor - an expression visitor
    
    contextItemType - the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to Type.ITEM_TYPE
    
    Returns:
    
    the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
    
    Throws:
    
    XPathException - if an error is discovered during this phase (typically a type error)
  - checkArguments
```
public void checkArguments(ExpressionVisitor visitor)
                    throws XPathException
```
    Description copied from class: SystemFunction
    
    Method called during static type checking
    
    Overrides:
    
    checkArguments in class SystemFunction
    
    Parameters:
    
    visitor - the expression visitor
    
    Throws:
    
    XPathException
  - 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 class SystemFunction
    
    Returns:
    
    the special properties, as a bit-significant integer
  - preEvaluate
```
public Expression preEvaluate(ExpressionVisitor visitor)
```
    preEvaluate: this method suppresses compile-time evaluation by doing nothing
    
    Overrides:
    
    preEvaluate in class FunctionCall
    
    Parameters:
    
    visitor - an expression visitor
    
    Returns:
    
    the result of the early evaluation, or the original expression, or potentially a simplified expression
  - copy
```
public Expression copy()
```
    Copy an expression. This makes a deep copy.
    
    Overrides:
    
    copy in class SystemFunction
    
    Returns:
    
    the copy of the original expression
  - 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 class 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
  - iterate
```
public SequenceIterator iterate(XPathContext context)
                         throws XPathException
```
    Enumerate the results of the expression
    
    Specified by:
    
    iterate in interface SequenceIterable
    
    Overrides:
    
    iterate in class Expression
    
    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
  - getIdrefMultiple
```
public static SequenceIterator getIdrefMultiple(DocumentInfo doc,
                                                SequenceIterator keys,
                                                XPathContext context)
                                         throws XPathException
```
    Get the result when multiple idref values are supplied. Note this is also called from compiled XQuery code.
    
    Parameters:
    
    doc - the document to be searched
    
    keys - the idref values supplied
    
    context - the dynamic execution context
    
    Returns:
    
    iterator over the result of the function
    
    Throws:
    
    XPathException

Class Idref

Field Summary

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

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

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

Constructor Summary

Method Summary

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

Idref

Method Detail

simplify

typeCheck

checkArguments

computeSpecialProperties

preEvaluate

copy

addToPathMap

iterate

getIdrefMultiple