Package com.icl.saxon.expr
Class RootExpression
java.lang.Object
com.icl.saxon.expr.Expression
com.icl.saxon.expr.NodeSetExpression
com.icl.saxon.expr.SingletonExpression
com.icl.saxon.expr.RootExpression
An expression whose value is always a set of nodes containing a single node, the document root.
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Field Summary
Fields inherited from class com.icl.saxon.expr.Expression
staticContext
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
display
(int level) Diagnostic print of expression structureboolean
evaluateAsBoolean
(Context context) Evaluate as a boolean.evaluateAsString
(Context context) Evaluate as a stringint
Determine which aspects of the context the expression depends on.Return the first element selected by this ExpressionPerform a partial evaluation of the expression, by eliminating specified dependencies on the context.simplify()
Simplify an expressionMethods inherited from class com.icl.saxon.expr.SingletonExpression
enumerate, evaluateAsNodeSet, isContextDocumentNodeSet, selectFirst
Methods inherited from class com.icl.saxon.expr.NodeSetExpression
evaluate, getDataType, outputStringValue
Methods inherited from class com.icl.saxon.expr.Expression
containsReferences, evaluateAsNumber, getStaticContext, indent, make, setStaticContext, usesCurrent
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Constructor Details
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RootExpression
public RootExpression()
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Method Details
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simplify
Simplify an expression- Overrides:
simplify
in classExpression
- Returns:
- the simplified expression
- Throws:
XPathException
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getNode
Return the first element selected by this Expression- Specified by:
getNode
in classSingletonExpression
- 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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evaluateAsString
Evaluate as a string- Overrides:
evaluateAsString
in classSingletonExpression
- Parameters:
context
- The context for evaluation- Returns:
- The concatenation of all the character data within the document
- Throws:
XPathException
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evaluateAsBoolean
Evaluate as a boolean.- Overrides:
evaluateAsBoolean
in classSingletonExpression
- Parameters:
context
- The context (not used)- Returns:
- true (always - because the nodeset is never empty)
- Throws:
XPathException
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getDependencies
public int getDependencies()Determine which aspects of the context the expression depends on. The result is a bitwise-or'ed value composed from constants such as Context.VARIABLES and Context.CURRENT_NODE- Specified by:
getDependencies
in classExpression
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reduce
Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.- Specified by:
reduce
in classExpression
- Parameters:
dependencies
- The dependencies to be removedcontext
- The context to be used for the partial evaluation- Returns:
- a new expression that does not have any of the specified dependencies
- Throws:
XPathException
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display
public void display(int level) Diagnostic print of expression structure- Specified by:
display
in classExpression
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