net.sf.saxon.functions.regex
Class JRegexIterator

java.lang.Object
  net.sf.saxon.functions.regex.JRegexIterator

All Implemented Interfaces:

RegexIterator, SequenceIterator

public class JRegexIterator
extends Object
implements RegexIterator

Class JRegexIterator - provides an iterator over matched and unmatched substrings. This implementation of RegexIterator uses the JDK regular expression engine.

Nested Class Summary

Nested classes/interfaces inherited from interface net.sf.saxon.functions.regex.RegexIterator

RegexIterator.OnGroup

Field Summary

Fields inherited from interface net.sf.saxon.om.SequenceIterator

GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

JRegexIterator(String string, Pattern pattern)
Construct a RegexIterator.

Method Summary

void	close() Close the iterator.
Item	current() Get the current item in the sequence
SequenceIterator	getAnother() Get another iterator over the same items
int	getProperties() Get properties of this iterator, as a bit-significant integer.
String	getRegexGroup(int number) Get a substring that matches a parenthesised group within the regular expression
SequenceIterator	getRegexGroupIterator() Get a sequence containing all the regex groups (except group 0, because we want to use indexing from 1).
boolean	isMatching() Determine whether the current item is a matching item or a non-matching item
Item	next() Get the next item in the sequence
int	position() Get the position of the current item in the sequence
void	processMatchingSubstring(XPathContext context, RegexIterator.OnGroup action) Process a matching substring, performing specified actions at the start and end of each captured subgroup.

Methods inherited from class java.lang.Object

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

Constructor Detail

JRegexIterator

public JRegexIterator(String string,
                      Pattern pattern)

Construct a RegexIterator. Note that the underlying matcher.find() method is called once to obtain each matching substring. But the iterator also returns non-matching substrings if these appear between the matching substrings.

Parameters:

string - the string to be analysed

pattern - the regular expression

Method Detail

next

public Item next()

Get the next item in the sequence

Specified by:

next in interface SequenceIterator

Returns:

the next item in the sequence

current

public Item current()

Get the current item in the sequence

Specified by:

current in interface SequenceIterator

Returns:

the item most recently returned by next()

position

public int position()

Get the position of the current item in the sequence

Specified by:

position in interface SequenceIterator

Returns:

the position of the item most recently returned by next(), starting at 1

close

public void close()

Description copied from interface: SequenceIterator

Close the iterator. This indicates to the supplier of the data that the client does not require any more items to be delivered by the iterator. This may enable the supplier to release resources. After calling close(), no further calls on the iterator should be made; if further calls are made, the effect of such calls is undefined.

(Currently, closing an iterator is important only when the data is being "pushed" in another thread. Closing the iterator terminates that thread and means that it needs to do no additional work. Indeed, failing to close the iterator may cause the push thread to hang waiting for the buffer to be emptied.)

Specified by:

close in interface SequenceIterator

getAnother

public SequenceIterator getAnother()

Get another iterator over the same items

Specified by:

getAnother in interface SequenceIterator

Returns:

a new iterator, positioned before the first item

getProperties

public int getProperties()

Get properties of this iterator, as a bit-significant integer.

Specified by:

getProperties in interface SequenceIterator

Returns:

the properties of this iterator. This will be some combination of properties such as SequenceIterator.GROUNDED, SequenceIterator.LAST_POSITION_FINDER, and SequenceIterator.LOOKAHEAD. It is always acceptable to return the value zero, indicating that there are no known special properties. It is acceptable for the properties of the iterator to change depending on its state.

isMatching

public boolean isMatching()

Determine whether the current item is a matching item or a non-matching item

Specified by:

isMatching in interface RegexIterator

Returns:

true if the current item (the one most recently returned by next()) is an item that matches the regular expression, or false if it is an item that does not match

getRegexGroup

public String getRegexGroup(int number)

Get a substring that matches a parenthesised group within the regular expression

Specified by:

getRegexGroup in interface RegexIterator

Parameters:

number - the number of the group to be obtained

Returns:

the substring of the current item that matches the n'th parenthesized group within the regular expression

getRegexGroupIterator

public SequenceIterator getRegexGroupIterator()

Get a sequence containing all the regex groups (except group 0, because we want to use indexing from 1). This is used by the saxon:analyze-string() higher-order extension function.

Specified by:

getRegexGroupIterator in interface RegexIterator

processMatchingSubstring

public void processMatchingSubstring(XPathContext context,
                                     RegexIterator.OnGroup action)
                              throws XPathException

Process a matching substring, performing specified actions at the start and end of each captured subgroup. This method will always be called when operating in "push" mode; it writes its result to context.getReceiver(). The matching substring text is all written to the receiver, interspersed with calls to the RegexIterator.OnGroup methods onGroupStart() and onGroupEnd().

Specified by:

processMatchingSubstring in interface RegexIterator

Parameters:

context - the dynamic evaluation context

action - defines the processing to be performed at the start and end of a group

Throws:

XPathException