Class CombinedNodeTest

  • All Implemented Interfaces:
    java.util.function.Predicate<NodeInfo>, ItemType, ItemType.WithSequenceTypeCache

    public class CombinedNodeTest
    extends NodeTest
    A CombinedNodeTest combines two node tests 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,*) intersect element(*,T))
    • 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

      • getUType

        public UType getUType()
        Get the corresponding UType. A UType is a union of primitive item types.
        Returns:
        the smallest UType that subsumes this item type
      • matches

        public boolean matches​(int nodeKind,
                               NodeName name,
                               SchemaType 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
        Returns:
        true if the node matches this node test
      • getMatcher

        public java.util.function.IntPredicate getMatcher​(NodeVectorTree tree)
        Description copied from class: NodeTest
        Get a matching function that can be used to test whether numbered nodes in a TinyTree or DominoTree satisfy the node test. (Calling this matcher must give the same result as calling matchesNode(tree.getNode(nodeNr)), but it may well be faster).
        Overrides:
        getMatcher in class NodeTest
        Parameters:
        tree - the tree against which the returned function will operate
        Returns:
        an IntPredicate; the matches() method of this predicate takes a node number as input, and returns true if and only if the node identified by this node number matches the node test.
      • test

        public boolean test​(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.
        Specified by:
        test in interface java.util.function.Predicate<NodeInfo>
        Overrides:
        test in class NodeTest
        Parameters:
        node - the node to be matched
        Returns:
        true if the node test is satisfied by the supplied node, false otherwise
      • toString

        public java.lang.String toString()
        Specified by:
        toString in interface ItemType
        Overrides:
        toString in class java.lang.Object
      • toExportString

        public java.lang.String toExportString()
        Return a string representation of this ItemType suitable for use in stylesheet export files. This differs from the result of toString() in that it will not contain any references to anonymous types. Note that it may also use the Saxon extended syntax for union types and tuple types. The default implementation returns the result of calling toString().
        Returns:
        the string representation as an instance of the XPath SequenceType construct
      • getContentTypeForAlphaCode

        public java.lang.String getContentTypeForAlphaCode()
      • addTypeDetails

        public void addTypeDetails​(DictionaryMap map)
        Add the "parameters" of the type to a Dictionary containing the type information in structured form
      • 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 java.util.Optional<IntSet> getRequiredNodeNames()
        Get the set of node names allowed by this NodeTest. This is returned as a set of Integer fingerprints. IntUniversalSet indicates that all names are permitted (i.e. that there are no constraints on the node name).
        Overrides:
        getRequiredNodeNames in class NodeTest
        Returns:
        the set of integer fingerprints of the node names that this node test can match; or absent if the set of names cannot be represented (for example, with the name tests *:xxx or xxx:*)
      • 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, or null if it is known that atomization will throw an error.
      • isAtomizable

        public boolean isAtomizable​(TypeHierarchy th)
        Ask whether values of this type are atomizable
        Specified by:
        isAtomizable in interface ItemType
        Overrides:
        isAtomizable in class NodeTest
        Parameters:
        th - the type hierarchy cache
        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
      • getMatchingNodeName

        public StructuredQName getMatchingNodeName()
        Description copied from class: NodeTest
        Get the name of the nodes matched by this nodetest, if it matches a specific name. Return null if the node test matches nodes of more than one name
        Overrides:
        getMatchingNodeName 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).
        Specified by:
        getDefaultPriority in interface ItemType
        Specified by:
        getDefaultPriority in class NodeTest
        Returns:
        the default priority for the pattern
      • getComponentNodeTests

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

        public NodeTest getOperand​(int which)
      • explainMismatch

        public java.util.Optional<java.lang.String> explainMismatch​(Item item,
                                                                    TypeHierarchy th)
        Get extra diagnostic information about why a supplied item does not conform to this item type, if available. If extra information is returned, it should be in the form of a complete sentence, minus the closing full stop. No information should be returned for obvious cases.
        Specified by:
        explainMismatch in interface ItemType
        Overrides:
        explainMismatch in class NodeTest
        Parameters:
        item - the item that doesn't match this type
        th - the type hierarchy cache
        Returns:
        optionally, a message explaining why the item does not match the type