Class Edits.Iterator

java.lang.Object
com.ibm.icu.text.Edits.Iterator
Enclosing class:
Edits
public static final class Edits.Iterator extends 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:
Status:
Stable ICU 59.

  • Method Details

    • next

      public boolean next()
      Advances the iterator to the next edit.
      Returns:
      true if there is another edit
      Status:
      Stable ICU 59.

    • 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
      Status:
      Stable ICU 59.

    • 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
      Status:
      Stable ICU 60.

    • 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
      Status:
      Stable ICU 60.

    • 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
      Status:
      Stable ICU 60.

    • 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.
      Status:
      Stable ICU 59.

    • 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.
      Status:
      Stable ICU 59.

    • 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.
      Status:
      Stable ICU 59.

    • 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
      Status:
      Stable ICU 59.

    • 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
      Status:
      Stable ICU 59.

    • 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
      Status:
      Stable ICU 59.

    • toString

      public 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 Object
      Returns:
      a string representation of the object.
      Status:
      Stable ICU 59.