: Class RootExpression
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
public class RootExpression extends SingletonExpression
An expression whose value is always a set of nodes containing a single node, the document root.
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
RootExpression
public RootExpression ()
simplify
public Expression simplify ()
throws XPathException
Simplify an expression
Overrides: simplify
in class Expression
Returns: the simplified expression
getNode
public NodeInfo getNode (Context context)
throws XPathException
Return the first element selected by this Expression
Overrides: getNode
in class SingletonExpression
Parameters: context
- The evaluation contextReturns: the NodeInfo of the first selected element, or null if no element
is selected
evaluateAsString
public java.lang.String evaluateAsString (Context context)
throws XPathException
Evaluate as a string
Overrides: evaluateAsString
in class SingletonExpression
Parameters: context
- The context for evaluationReturns: The concatenation of all the character data within the document
evaluateAsBoolean
public boolean evaluateAsBoolean (Context context)
throws XPathException
Evaluate as a boolean.
Overrides: evaluateAsBoolean
in class SingletonExpression
Parameters: context
- The context (not used)Returns: true (always - because the nodeset is never empty)
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
Overrides: getDependencies
in class Expression
reduce
public Expression reduce (int dependencies,
Context context)
throws XPathException
Perform a partial evaluation of the expression, by eliminating specified dependencies
on the context.
Overrides: reduce
in class Expression
Parameters: dependencies
- The dependencies to be removedcontext
- The context to be used for the partial evaluationReturns: a new expression that does not have any of the specified
dependencies
display
public void display (int level)
Diagnostic print of expression structure
Overrides: display
in class Expression