com.icl.saxon.pattern
Class LocationPathPattern

java.lang.Object
  com.icl.saxon.pattern.Pattern
      com.icl.saxon.pattern.LocationPathPattern

public final class LocationPathPattern

extends Pattern

A LocationPathPattern represents a path, e.g. of the form A/B/C... The components are represented as a linked list, each component pointing to its predecessor

Field Summary

Pattern	ancestorPattern
protected Expression	equivalentExpr
protected Expression[]	filters
protected boolean	firstElementPattern
protected boolean	lastElementPattern
NodeTest	nodeTest
protected int	numberOfFilters
Pattern	parentPattern
protected boolean	specialFilter

Fields inherited from class com.icl.saxon.pattern.Pattern

originalText, staticContext

Constructor Summary

LocationPathPattern()

Method Summary

void	addFilter(Expression filter) Add a filter to the pattern (while under construction)
int	getFingerprint() Determine the fingerprint of nodes to which this pattern applies.
short	getNodeType() Determine the types of nodes to which this pattern applies.
boolean	isRelative() Determine if the pattern uses positional filters
boolean	matches(NodeInfo node, Context context) Determine whether this Pattern matches the given Node
boolean	matchesX(NodeInfo node, Context context) Determine whether the pattern matches a given node.
Pattern	simplify() Simplify the pattern: perform any context-independent optimisations

Methods inherited from class com.icl.saxon.pattern.Pattern

getDefaultPriority, getLineNumber, getStaticContext, getSystemId, make, setOriginalText, setStaticContext, toString

Methods inherited from class java.lang.Object

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

Field Detail

parentPattern

public Pattern parentPattern

ancestorPattern

public Pattern ancestorPattern

nodeTest

public NodeTest nodeTest

filters

protected Expression[] filters

numberOfFilters

protected int numberOfFilters

equivalentExpr

protected Expression equivalentExpr

firstElementPattern

protected boolean firstElementPattern

lastElementPattern

protected boolean lastElementPattern

specialFilter

protected boolean specialFilter

Constructor Detail

LocationPathPattern

public LocationPathPattern()

Method Detail

addFilter

public void addFilter(Expression filter)

Add a filter to the pattern (while under construction)

Parameters:

filter - The predicate (a boolean expression or numeric expression) to be added

simplify

public Pattern simplify()
                 throws XPathException

Simplify the pattern: perform any context-independent optimisations

Overrides:

simplify in class Pattern

Returns:

the optimised Pattern

Throws:

XPathException

matchesX

public boolean matchesX(NodeInfo node,
                        Context context)
                 throws XPathException

Determine whether the pattern matches a given node.

Parameters:

node - the node to be tested

Returns:

true if the pattern matches, else false

Throws:

XPathException

matches

public boolean matches(NodeInfo node,
                       Context context)
                throws XPathException

Description copied from class: Pattern

Determine whether this Pattern matches the given Node

Specified by:

matches in class Pattern

Parameters:

node - The NodeInfo representing the Element or other node to be tested against the Pattern

context - The context in which the match is to take place. Only relevant if the pattern uses variables.

Returns:

true if the node matches the Pattern, false otherwise

Throws:

XPathException

getNodeType

public short getNodeType()

Determine the types of nodes to which this pattern applies. Used for optimisation. For patterns that match nodes of several types, return Node.NODE

Overrides:

getNodeType in class Pattern

Returns:

the type of node matched by this pattern. e.g. Node.ELEMENT or Node.TEXT

getFingerprint

public int getFingerprint()

Determine the fingerprint of nodes to which this pattern applies. Used for optimisation.

Overrides:

getFingerprint in class Pattern

Returns:

the fingerprint of nodes matched by this pattern.

isRelative

public boolean isRelative()
                   throws XPathException

Determine if the pattern uses positional filters

Returns:

true if there is a numeric filter in the pattern, or one that uses the position() or last() functions

Throws:

XPathException