This module implements the Levenshtein edit distance. The Levenshtein edit
distance is a measure of the degree of proximity between two strings. This
distance is the number of substitutions, deletions or insertions ("edits")
needed to transform one string into the other one (and vice versa). When two
strings have distance 0, they are the same. A good point to start is:

&fastdistance can be called with two scalars and is faster in most cases.

See also Text::LevenshteinXS on CPAN if you do not require a perl-only
implementation. It is extremely faster in nearly all cases.

See also Text::WagnerFischer on CPAN for a configurable edit distance, i.e. for
configurable costs (weights) for the edits.