Class RootExpression


  • public class RootExpression
    extends SingletonExpression
    An expression whose value is always a set of nodes containing a single node, the document root.
    • Constructor Detail

      • RootExpression

        public RootExpression()
    • Method Detail

      • 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 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.
        Specified by:
        reduce in 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
        Throws:
        XPathException
      • display

        public void display​(int level)
        Diagnostic print of expression structure
        Specified by:
        display in class Expression