This module implements the Brew edit distance that is very close to the
dynamic programming technique used for the Wagner-Fischer (and so for
the Levenshtein) edit distance. The difference here is that you have
separated costs for the DELetion and INSertion operations (but with the
default to 1 for both, you obtain the Levenshtein edit distance). But
the most interesting feature is that you can obtain the description of
the edits needed to transform the first string into the second one (not
vice versa: here DELetions are separated from INSertions).