Class Edits.Iterator

  • Enclosing class:
    Edits

    public static final class Edits.Iterator
    extends java.lang.Object
    Access to the list of edits.

    At any moment in time, an instance of this class points to a single edit: a "window" into a span of the source string and the corresponding span of the destination string. The source string span starts at sourceIndex() and runs for oldLength() chars; the destination string span starts at destinationIndex() and runs for newLength() chars.

    The iterator can be moved between edits using the next(), findSourceIndex(int), and findDestinationIndex(int) methods. Calling any of these methods mutates the iterator to make it point to the corresponding edit.

    For more information, see the documentation for Edits.

    Note: Although this class is called "Iterator", it does not implement Iterator.

    See Also:
    Edits.getCoarseIterator(), Edits.getFineIterator()
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int destinationIndex()
      The start index of the current span in the destination string; the span has length newLength().
      int destinationIndexFromSourceIndex​(int i)
      Computes the destination index corresponding to the given source index.
      boolean findDestinationIndex​(int i)
      Moves the iterator to the edit that contains the destination index.
      boolean findSourceIndex​(int i)
      Moves the iterator to the edit that contains the source index.
      boolean hasChange()
      Returns whether the edit currently represented by the iterator is a change edit.
      int newLength()
      The length of the current span in the destination string, which starts at destinationIndex(), or in the replacement string, which starts at replacementIndex().
      boolean next()
      Advances the iterator to the next edit.
      int oldLength()
      The length of the current span in the source string, which starts at sourceIndex().
      int replacementIndex()
      The start index of the current span in the replacement string; the span has length newLength().
      int sourceIndex()
      The start index of the current span in the source string; the span has length oldLength().
      int sourceIndexFromDestinationIndex​(int i)
      Computes the source index corresponding to the given destination index.
      java.lang.String toString()
      A string representation of the current edit represented by the iterator for debugging.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Method Detail

      • next

        public boolean next()
        Advances the iterator to the next edit.
        Returns:
        true if there is another edit
      • findSourceIndex

        public boolean findSourceIndex​(int i)
        Moves the iterator to the edit that contains the source index. The source index may be found in a no-change edit even if normal iteration would skip no-change edits. Normal iteration can continue from a found edit.

        The iterator state before this search logically does not matter. (It may affect the performance of the search.)

        The iterator state after this search is undefined if the source index is out of bounds for the source string.

        Parameters:
        i - source index
        Returns:
        true if the edit for the source index was found
      • findDestinationIndex

        public boolean findDestinationIndex​(int i)
        Moves the iterator to the edit that contains the destination index. The destination index may be found in a no-change edit even if normal iteration would skip no-change edits. Normal iteration can continue from a found edit.

        The iterator state before this search logically does not matter. (It may affect the performance of the search.)

        The iterator state after this search is undefined if the source index is out of bounds for the source string.

        Parameters:
        i - destination index
        Returns:
        true if the edit for the destination index was found
      • destinationIndexFromSourceIndex

        public int destinationIndexFromSourceIndex​(int i)
        Computes the destination index corresponding to the given source index. If the source index is inside a change edit (not at its start), then the destination index at the end of that edit is returned, since there is no information about index mapping inside a change edit.

        (This means that indexes to the start and middle of an edit, for example around a grapheme cluster, are mapped to indexes encompassing the entire edit. The alternative, mapping an interior index to the start, would map such an interval to an empty one.)

        This operation will usually but not always modify this object. The iterator state after this search is undefined.

        Parameters:
        i - source index
        Returns:
        destination index; undefined if i is not 0..string length
      • sourceIndexFromDestinationIndex

        public int sourceIndexFromDestinationIndex​(int i)
        Computes the source index corresponding to the given destination index. If the destination index is inside a change edit (not at its start), then the source index at the end of that edit is returned, since there is no information about index mapping inside a change edit.

        (This means that indexes to the start and middle of an edit, for example around a grapheme cluster, are mapped to indexes encompassing the entire edit. The alternative, mapping an interior index to the start, would map such an interval to an empty one.)

        This operation will usually but not always modify this object. The iterator state after this search is undefined.

        Parameters:
        i - destination index
        Returns:
        source index; undefined if i is not 0..string length
      • hasChange

        public boolean hasChange()
        Returns whether the edit currently represented by the iterator is a change edit.
        Returns:
        true if this edit replaces oldLength() units with newLength() different ones. false if oldLength units remain unchanged.
      • oldLength

        public int oldLength()
        The length of the current span in the source string, which starts at sourceIndex().
        Returns:
        the number of units in the source string which are replaced or remain unchanged.
      • newLength

        public int newLength()
        The length of the current span in the destination string, which starts at destinationIndex(), or in the replacement string, which starts at replacementIndex().
        Returns:
        the number of units in the destination string, if hasChange() is true. Same as oldLength if hasChange() is false.
      • sourceIndex

        public int sourceIndex()
        The start index of the current span in the source string; the span has length oldLength().
        Returns:
        the current index into the source string
      • replacementIndex

        public int replacementIndex()
        The start index of the current span in the replacement string; the span has length newLength(). Well-defined only if the current edit is a change edit.

        The replacement string is the concatenation of all substrings of the destination string corresponding to change edits.

        This method is intended to be used together with operations that write only replacement characters (e.g., CaseMap.omitUnchangedText()). The source string can then be modified in-place.

        Returns:
        the current index into the replacement-characters-only string, not counting unchanged spans
      • destinationIndex

        public int destinationIndex()
        The start index of the current span in the destination string; the span has length newLength().
        Returns:
        the current index into the full destination string
      • toString

        public java.lang.String toString()
        A string representation of the current edit represented by the iterator for debugging. You should not depend on the contents of the return string; it may change over time.
        Overrides:
        toString in class java.lang.Object
        Returns:
        a string representation of the object.