Provides support for finding the differences between two or three sequences of comparable entities.

Package Specification

The class Differencer finds longest sequences of matching and non-matching comparable entities.

Clients must supply the input to the differencer as an implementation of the IRangeComparator interface.
An IRangeComparator breaks the input data into a sequence of entities and provides a method for comparing
one entity with the entity in another IRangeComparator.
For example, to compare two text documents and find longest common sequences
of matching and non-matching lines, the implementation of IRangeComparator must break the document
into lines and provide a method for testing whether two lines are considered equal.

The differencer returns the differences among these sequences as an array of RangeDifference objects.
Every single RangeDifference describes kind of difference (no change, change, addition, deletion)
and the corresponding ranges of the underlying comparable entities in the two or three inputs.

The algorithm used is an objectified version of one described in:
A File Comparison Program, by Webb Miller and Eugene W. Myers,
Software Practice and Experience, Vol. 15, Nov. 1985.