Package net.sf.saxon.regex

## Class History

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

-     public class History
      extends java.lang.Object

  The History object is used to avoid backtracking too far. In particular, when a greedy repeat operator allows zero repetitions (something we try to optimize away, but it isn't always possible, then if we backtrack all the way to the start position, we only allow a match at this position if no match at this position is currently recorded in the history.

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `History()` |

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `boolean` | `isDuplicateZeroLengthMatch​(Operation op, int position)` |

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### History

          public History()

  - ### Method Detail

    - #### isDuplicateZeroLengthMatch

          public boolean isDuplicateZeroLengthMatch​(Operation op,
                                                    int position)