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, wait, wait, wait | 
 
RootExpression
public RootExpression()
simplify
public Expression simplify()
                    throws org.xml.sax.SAXException
- Simplify an expression- 
- Overrides:
- simplifyin class- Expression
 
- 
- Returns:
- the simplified expression
 
getNode
public NodeInfo getNode(Context context)
                 throws org.xml.sax.SAXException
- Return the first element selected by this Expression- 
- Overrides:
- getNodein class- SingletonExpression
 
- 
- Parameters:
- context- The evaluation context
- Returns:
- the NodeInfo of the first selected element, or null if no element
 is selected
 
evaluateAsString
public java.lang.String evaluateAsString(Context context)
                                  throws org.xml.sax.SAXException
- Evaluate as a string- 
- Overrides:
- evaluateAsStringin class- SingletonExpression
 
- 
- Parameters:
- context- The context for evaluation
- Returns:
- The concatenation of all the character data within the document
 
evaluateAsBoolean
public boolean evaluateAsBoolean(Context context)
                          throws org.xml.sax.SAXException
- Evaluate as a boolean.- 
- Overrides:
- evaluateAsBooleanin class- SingletonExpression
 
- 
- Parameters:
- context- The context (not used)
- Returns:
- true (always - because the nodeset is never empty)
 
toString
public java.lang.String toString()
- Get a string representation of the expression- 
- Overrides:
- toStringin class- java.lang.Object
 
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:
- getDependenciesin class- Expression
 
reduce
public Expression reduce(int dependencies,
                         Context context)
                  throws org.xml.sax.SAXException
- Perform a partial evaluation of the expression, by eliminating specified dependencies
 on the context.- 
- Overrides:
- reducein class- Expression
 
- 
- Parameters:
- dependencies- The dependencies to be removed
- context- The context to be used for the partial evaluation
- Returns:
- a new expression that does not have any of the specified
 dependencies