Package net.sf.saxon.expr
Class RootExpression
java.lang.Object
net.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.SingleNodeExpression
net.sf.saxon.expr.RootExpression
- All Implemented Interfaces:
Serializable
,SourceLocator
,Container
,Expression
,InstructionInfoProvider
An expression whose value is always a set of nodes containing a single node,
the document root. This corresponds to the XPath Expression "/", including the implicit
"/" at the start of a path expression with a leading "/".
- See Also:
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Field Summary
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
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionfinal int
Specify that the expression returns a singletonvoid
display
(int level, PrintStream out, Configuration config) Diagnostic print of expression structureboolean
Is this expression the same as another expression?int
Determine which aspects of the context the expression depends on.Determine the data type of the items returned by this expressiongetNode
(XPathContext context) Return the first element selected by this Expressionint
hashCode()
get HashCode for comparing two expressionsMethods inherited from class net.sf.saxon.expr.SingleNodeExpression
computeSpecialProperties, effectiveBooleanValue, evaluateItem, iterate, optimize, typeCheck
Methods inherited from class net.sf.saxon.expr.ComputedExpression
adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, iterateSubExpressions, markTailFunctionCalls, process, promote, replaceSubExpression, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, simplify, suppressValidation, typeError
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Constructor Details
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RootExpression
public RootExpression()
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Method Details
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equals
Is this expression the same as another expression? -
computeCardinality
public final int computeCardinality()Specify that the expression returns a singleton- Overrides:
computeCardinality
in classSingleNodeExpression
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getItemType
Determine the data type of the items returned by this expression- Specified by:
getItemType
in interfaceExpression
- Overrides:
getItemType
in classSingleNodeExpression
- Parameters:
th
-- Returns:
- Type.NODE
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hashCode
public int hashCode()get HashCode for comparing two expressions -
getNode
Return the first element selected by this Expression- Specified by:
getNode
in classSingleNodeExpression
- Parameters:
context
- The evaluation context- Returns:
- the NodeInfo of the first selected element, or null if no element is selected
- Throws:
XPathException
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getIntrinsicDependencies
public int getIntrinsicDependencies()Determine which aspects of the context the expression depends on. The result is a bitwise-or'ed value composed from constants such as StaticProperty.VARIABLES and StaticProperty.CURRENT_NODE- Overrides:
getIntrinsicDependencies
in classSingleNodeExpression
- Returns:
- a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty
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display
Diagnostic print of expression structure- Parameters:
level
- indentation level for this expressionout
- Output destinationconfig
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