Class CombinedNodeTest

  • All Implemented Interfaces:
    java.io.Serializable, ItemType

    public class CombinedNodeTest
    extends NodeTest
    A CombinedNodeTest combines two nodetests using one of the operators union (=or), intersect (=and), difference (= "and not"). This arises when optimizing a union (etc) of two path expressions using the same axis. A CombinedNodeTest is also used to support constructs such as element(N,T), which can be expressed as (element(N,*) AND element(*,T))
    Author:
    Michael H. Kay
    See Also:
    Serialized Form
    • Constructor Detail

      • CombinedNodeTest

        public CombinedNodeTest​(NodeTest nt1,
                                int operator,
                                NodeTest nt2)
        Create a NodeTest that combines two other node tests
        Parameters:
        nt1 - the first operand. Note that if the defaultPriority of the pattern is required, it will be taken from that of the first operand.
        operator - one of Token.UNION, Token.INTERSECT, Token.EXCEPT
        nt2 - the second operand
    • Method Detail

      • 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
      • toString

        public java.lang.String toString​(NamePool pool)
        Description copied from class: NodeTest
        Display the type descriptor for diagnostics
        Specified by:
        toString in interface ItemType
        Overrides:
        toString in class NodeTest
        Parameters:
        pool - the name pool
        Returns:
        a string representation of the type, in notation resembling but not necessarily identical to XPath syntax
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
      • getSuperType

        public ItemType getSuperType​(TypeHierarchy th)
        Get the supertype of this type. This isn't actually a well-defined concept: the types form a lattice rather than a strict hierarchy.
        Specified by:
        getSuperType in interface ItemType
        Overrides:
        getSuperType in class NodeTest
        Parameters:
        th - the type hierarchy cache
        Returns:
        the supertype, or null if this type is item()
      • getNodeKindMask

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

        public int getPrimitiveType()
        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
      • getRequiredNodeNames

        public IntSet getRequiredNodeNames()
        Get the set of node names allowed by this NodeTest. This is returned as a set of Integer fingerprints. A null value indicates that all names are permitted (i.e. that there are no constraints on the node name). The default implementation returns null.
        Overrides:
        getRequiredNodeNames in class NodeTest
        Returns:
        the set of integer fingerprints of the node names that this node test can match.
      • getContentType

        public SchemaType getContentType()
        Get the content type allowed by this NodeTest (that is, the type annotation of the matched nodes). Return AnyType if there are no restrictions. The default implementation returns AnyType.
        Overrides:
        getContentType in class NodeTest
        Returns:
        the type annotation that all nodes matching this NodeTest must satisfy
      • getAtomizedItemType

        public AtomicType getAtomizedItemType()
        Get the item type of the atomic values that will be produced when an item of this type is atomized (assuming that atomization succeeds)
        Specified by:
        getAtomizedItemType in interface ItemType
        Overrides:
        getAtomizedItemType in class NodeTest
        Returns:
        the best available item type of the atomic values that will be produced when an item of this type is atomized
      • isAtomizable

        public boolean isAtomizable()
        Ask whether values of this type are atomizable
        Specified by:
        isAtomizable in interface ItemType
        Overrides:
        isAtomizable in class NodeTest
        Returns:
        true unless it is known that these items will be elements with element-only content, in which case return false
      • getFingerprint

        public int getFingerprint()
        Get the name of the nodes matched by this nodetest, if it matches a specific name. Return -1 if the node test matches nodes of more than one name
        Overrides:
        getFingerprint in class NodeTest
      • isNillable

        public boolean isNillable()
        Determine whether the content type (if present) is nillable
        Overrides:
        isNillable in class NodeTest
        Returns:
        true if the content test (when present) can match nodes that are nilled
      • hashCode

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

        public boolean equals​(java.lang.Object other)
        Indicates whether some other object is "equal to" this one.
        Overrides:
        equals in class java.lang.Object
      • getDefaultPriority

        public double getDefaultPriority()
        Get the default priority of this nodeTest when used as a pattern. In the case of a union, this will always be (arbitrarily) the default priority of the first operand. In other cases, again somewhat arbitrarily, it is 0.25, reflecting the common usage of an intersection to represent the pattern element(E, T).
        Returns:
        the default priority
      • getComponentNodeTests

        public NodeTest[] getComponentNodeTests()
        Get the two parts of the combined node test
        Returns:
        the two operands