Class EmptySequenceTest

java.lang.Object
net.sf.saxon.pattern.NodeTest
net.sf.saxon.pattern.EmptySequenceTest
All Implemented Interfaces:
Serializable, ItemType
public final class EmptySequenceTest extends NodeTest
NodeTest is an interface that enables a test of whether a node has a particular name and type. An EmptySequenceTest matches no nodes or atomic values: it corresponds to the type empty-sequence().
Author:
Michael H. Kay
See Also:

  • Method Details

    • getInstance

      public static EmptySequenceTest getInstance()
      Get a NoNodeTest instance

    • getPrimitiveType

      public final int getPrimitiveType()
      Description copied from class: NodeTest
      Get the basic kind of object that this ItemType matches: for a NodeTest, this is the kind of node, or Type.Node if it matches different kinds of nodes.
      Specified by:
      getPrimitiveType in interface ItemType
      Overrides:
      getPrimitiveType in class NodeTest
      Returns:
      the node kind matched by this node test

    • getPrimitiveItemType

      public ItemType getPrimitiveItemType()
      Get the primitive item type corresponding to this item type. For item(), this is Type.ITEM. For node(), it is Type.NODE. For specific node kinds, it is the value representing the node kind, for example Type.ELEMENT. For anyAtomicValue it is Type.ATOMIC_VALUE. For numeric it is Type.NUMBER. For other atomic types it is the primitive type as defined in XML Schema, except that INTEGER is considered to be a primitive type.
      Specified by:
      getPrimitiveItemType in interface ItemType
      Overrides:
      getPrimitiveItemType in class NodeTest
      Returns:
      the corresponding primitive type

    • matchesItem

      public boolean matchesItem(Item item, boolean allowURIPromotion, Configuration config)
      Test whether a given item conforms to this type
      Specified by:
      matchesItem in interface ItemType
      Overrides:
      matchesItem in class NodeTest
      Parameters:
      item - The item to be tested
      allowURIPromotion -
      config -
      Returns:
      true if the item is an instance of this type; false otherwise

    • matches

      public boolean matches(int nodeKind, NodeName name, int annotation)
      Test whether this node test is satisfied by a given node. This method is only fully supported for a subset of NodeTests, because it doesn't provide all the information needed to evaluate all node tests. In particular (a) it can't be used to evaluate a node test of the form element(N,T) or schema-element(E) where it is necessary to know whether the node is nilled, and (b) it can't be used to evaluate a node test of the form document-node(element(X)). This in practice means that it is used (a) to evaluate the simple node tests found in the XPath 1.0 subset used in XML Schema, and (b) to evaluate node tests where the node kind is known to be an attribute.
      Specified by:
      matches in class NodeTest
      Parameters:
      nodeKind - The kind of node to be matched
      name - identifies the expanded name of the node to be matched. The value should be null for a node with no name.
      annotation - The actual content type of the node

    • matches

      public boolean matches(TinyTree tree, int nodeNr)
      Test whether this node test is satisfied by a given node on a TinyTree. The node must be a document, element, text, comment, or processing instruction node. This method is provided so that when navigating a TinyTree a node can be rejected without actually instantiating a NodeInfo object.
      Overrides:
      matches in class NodeTest
      Parameters:
      tree - the TinyTree containing the node
      nodeNr - the number of the node within the TinyTree
      Returns:
      true if the node matches the NodeTest, otherwise false

    • matches

      public boolean matches(NodeInfo node)
      Test whether this node test is satisfied by a given node. This alternative method is used in the case of nodes where calculating the fingerprint is expensive, for example DOM or JDOM nodes.
      Overrides:
      matches in class NodeTest
      Parameters:
      node - the node to be matched

    • getDefaultPriority

      public final double getDefaultPriority()
      Determine the default priority of this node test when used on its own as a Pattern
      Returns:
      the default priority

    • getNodeKindMask

      public int getNodeKindMask()
      Get a mask indicating which kinds of nodes this NodeTest can match. This is a combination of bits: 1invalid input: '<'invalid input: '<'Type.ELEMENT for element nodes, 1invalid input: '<'invalid input: '<'Type.TEXT for text nodes, and so on.
      Overrides:
      getNodeKindMask in class NodeTest
      Returns:
      a combination of bits: 1invalid input: '<'invalid input: '<'Type.ELEMENT for element nodes, 1invalid input: '<'invalid input: '<'Type.TEXT for text nodes, and so on

    • visitNamedSchemaComponents

      public void visitNamedSchemaComponents(SchemaComponentVisitor visitor) throws XPathException
      Visit all the schema components used in this ItemType definition
      Specified by:
      visitNamedSchemaComponents in interface ItemType
      Overrides:
      visitNamedSchemaComponents in class NodeTest
      Parameters:
      visitor - the visitor class to be called when each component is visited
      Throws:
      XPathException - if an error occurs

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • hashCode

      public int hashCode()
      Returns a hash code value for the object.
      Overrides:
      hashCode in class Object