Package net.sf.saxon.regex

## Class JRegexIterator

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

- All Implemented Interfaces:
    `java.io.Closeable`, `java.lang.AutoCloseable`, `LastPositionFinder`, `SequenceIterator`, `RegexIterator`

      public class JRegexIterator
      extends java.lang.Object
      implements RegexIterator, LastPositionFinder

  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.regex.RegexIterator

      `RegexIterator.MatchHandler`

    - ### Nested classes/interfaces inherited from interface net.sf.saxon.om.SequenceIterator

      `SequenceIterator.Property`

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `JRegexIterator​(java.lang.String string, java.util.regex.Pattern pattern)` | Construct a RegexIterator.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `int` | `getLength()` | Get the last position (that is, the number of items in the sequence).
    `int` | `getNumberOfGroups()` | Get the number of captured groups
    `java.util.EnumSet<SequenceIterator.Property>` | `getProperties()` | Get properties of this iterator, as a bit-significant integer.
    `java.lang.String` | `getRegexGroup​(int number)` | Get a substring that matches a parenthesised group within the regular expression
    `boolean` | `isMatching()` | Determine whether the current item is a matching item or a non-matching item
    `StringValue` | `next()` | Get the next item in the sequence
    `void` | `processMatchingSubstring​(RegexIterator.MatchHandler 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`

    - ### Methods inherited from interface net.sf.saxon.om.SequenceIterator

      `close, forEachOrFail, materialize`

- - ### Constructor Detail

    - #### JRegexIterator

          public JRegexIterator​(java.lang.String string,
                                java.util.regex.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

    - #### getLength

          public int getLength()
                        throws XPathException

      Description copied from interface: `LastPositionFinder`
      Get the last position (that is, the number of items in the sequence). This method is non-destructive: it does not change the state of the iterator. The result is undefined if the next() method of the iterator has already returned null. This method must not be called unless the result of getProperties() on the iterator includes the bit setting `SequenceIterator.Property.LAST_POSITION_FINDER`
      Specified by:
        `getLength` in interface `LastPositionFinder`
      Returns:
        the number of items in the sequence
      Throws:
        `XPathException` - if an error occurs evaluating the sequence in order to determine the number of items

    - #### next

          public StringValue next()

      Get the next item in the sequence
      Specified by:
        `next` in interface `RegexIterator`
      Specified by:
        `next` in interface `SequenceIterator`
      Returns:
        the next item in the sequence

    - #### getProperties

          public java.util.EnumSet<SequenceIterator.Property> 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.Property.GROUNDED`, `SequenceIterator.Property.LAST_POSITION_FINDER`, and `SequenceIterator.Property.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 java.lang.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

    - #### getNumberOfGroups

          public int getNumberOfGroups()

      Get the number of captured groups
      Specified by:
        `getNumberOfGroups` in interface `RegexIterator`

    - #### processMatchingSubstring

          public void processMatchingSubstring​(RegexIterator.MatchHandler 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 methods onGroupStart() and onGroupEnd().
      Specified by:
        `processMatchingSubstring` in interface `RegexIterator`
      Parameters:
        `action` - defines the processing to be performed at the start and end of a group
      Throws:
        `XPathException`