Package org.eclipse.compare.rangedifferencer

Interface IRangeComparator

All Known Subinterfaces:
ITokenComparator
All Known Implementing Classes:
DocLineComparator, TokenComparator
public interface IRangeComparator
For breaking an object to compare into a sequence of comparable entities.

It is used by RangeDifferencer to find longest sequences of matching and non-matching ranges.

For example, to compare two text documents and find longest common sequences of matching and non-matching lines, the implementation must break the document into lines. getRangeCount would return the number of lines in the document, and rangesEqual would compare a specified line given with one in another IRangeComparator.

Clients should implement this interface; there is no standard implementation.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    getRangeCount()
    Returns the number of comparable entities.
    boolean
    rangesEqual(int thisIndex, IRangeComparator other, int otherIndex)
    Returns whether the comparable entity given by the first index matches an entity specified by the other IRangeComparator and index.
    boolean
    skipRangeComparison(int length, int maxLength, IRangeComparator other)
    Returns whether a comparison should be skipped because it would be too costly (or lengthy).

  • Method Details

    • getRangeCount

      int getRangeCount()
      Returns the number of comparable entities.
      Returns:
      the number of comparable entities

    • rangesEqual

      boolean rangesEqual(int thisIndex, IRangeComparator other, int otherIndex)
      Returns whether the comparable entity given by the first index matches an entity specified by the other IRangeComparator and index.
      Parameters:
      thisIndex - the index of the comparable entity within this IRangeComparator
      other - the IRangeComparator to compare this with
      otherIndex - the index of the comparable entity within the other IRangeComparator
      Returns:
      true if the comparable entities are equal

    • skipRangeComparison

      boolean skipRangeComparison(int length, int maxLength, IRangeComparator other)
      Returns whether a comparison should be skipped because it would be too costly (or lengthy).
      Parameters:
      length - a number on which to base the decision whether to return true or false
      maxLength - another number on which to base the decision whether to return true or false
      other - the other IRangeComparator to compare with
      Returns:
      true to avoid a too lengthy range comparison