Class RootExpression

All Implemented Interfaces:
Serializable, SourceLocator, Container, Expression, InstructionInfoProvider

public class RootExpression extends SingleNodeExpression
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:
  • Constructor Details

    • RootExpression

      public RootExpression()
  • Method Details

    • equals

      public boolean equals(Object other)
      Is this expression the same as another expression?
      Overrides:
      equals in class Object
    • computeCardinality

      public final int computeCardinality()
      Specify that the expression returns a singleton
      Overrides:
      computeCardinality in class SingleNodeExpression
    • getItemType

      public ItemType getItemType(TypeHierarchy th)
      Determine the data type of the items returned by this expression
      Specified by:
      getItemType in interface Expression
      Overrides:
      getItemType in class SingleNodeExpression
      Parameters:
      th -
      Returns:
      Type.NODE
    • hashCode

      public int hashCode()
      get HashCode for comparing two expressions
      Overrides:
      hashCode in class Object
    • getNode

      public NodeInfo getNode(XPathContext context) throws XPathException
      Return the first element selected by this Expression
      Specified by:
      getNode in class SingleNodeExpression
      Parameters:
      context - The evaluation context
      Returns:
      the NodeInfo of the first selected element, or null if no element is selected
      Throws:
      XPathException
    • 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 class SingleNodeExpression
      Returns:
      a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty
    • display

      public void display(int level, PrintStream out, Configuration config)
      Diagnostic print of expression structure
      Parameters:
      level - indentation level for this expression
      out - Output destination
      config -