Package net.sf.saxon.pattern

Class NodeSelector

java.lang.Object

net.sf.saxon.pattern.NodeTest

net.sf.saxon.pattern.NodeSelector

All Implemented Interfaces:

NodePredicate, ItemType, ItemTypeWithSequenceTypeCache

public class NodeSelector
extends NodeTest

A NodeTest that wraps a general Predicate applied to nodes.

This is needed for C#, where it is not possible for a method such as NodeInfo.iterateAxis(int, NodePredicate) to accept either a NodeTest object or a Predicate supplied as a lambda expression. To supply a predicate, it is therefore necessary to wrap it in a NodePredicate.

Method Summary

Modifier and Type	Method	Description
double	getDefaultPriority()	Determine the default priority to use if this node-test appears as a match pattern for a template with no explicit priority attribute.
UType	getUType()	Get the corresponding UType.
boolean	matches(int nodeKind, NodeName name, SchemaType annotation)	Test whether this node test is satisfied by a given node.
static NodeSelector	of(java.util.function.Predicate<? super NodeInfo> predicate)	Create a NodeTest based on a supplied predicate.
boolean	test(NodeInfo node)	Test whether this node test is satisfied by a given node.

Methods inherited from class net.sf.saxon.pattern.NodeTest

copy, explainMismatch, getAtomizedItemType, getBasicAlphaCode, getContentType, getFingerprint, getGenre, getMatcher, getMatchingNodeName, getPrimitiveItemType, getPrimitiveType, getRequiredNodeNames, isAtomicType, isAtomizable, isNillable, isPlainType, matches, one, oneOrMore, toShortString, zeroOrMore, zeroOrOne

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface net.sf.saxon.type.ItemType

getFullAlphaCode, getNormalizedDefaultPriority, toExportString

Method Detail

of

public static NodeSelector of(java.util.function.Predicate<? super NodeInfo> predicate)

Create a NodeTest based on a supplied predicate. The NodeTest selects a node if the predicate returns true.

Parameters:

predicate - the supplied predicate (a boolean function of a node)

Returns:

a NodeTest matching the selected nodes

test

public boolean test(NodeInfo node)

Description copied from class: NodeTest

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. The default implementation calls the method NodeTest.matches(int, NodeName, SchemaType)

Specified by:

test in interface NodePredicate

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

getDefaultPriority

public double getDefaultPriority()

Description copied from class: NodeTest

Determine the default priority to use if this node-test appears as a match pattern for a template with no explicit priority attribute.

Specified by:

getDefaultPriority in interface ItemType

Specified by:

getDefaultPriority in class NodeTest

Returns:

the default priority for the pattern

matches

public boolean matches(int nodeKind,
                       NodeName name,
                       SchemaType annotation)

Description copied from class: NodeTest

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. Null means no constraint.

Returns:

true if the node matches this node test

getUType

public UType getUType()

Description copied from interface: ItemType

Get the corresponding UType. A UType is a union of primitive item types.

Returns:

the smallest UType that subsumes this item type