=pod 

=encoding utf8

=head1 Name

Text::Levenshtein::Damerau - Levenshtein and Damerau Levenshtein edit distances

=for HTML <a href="https://travis-ci.org/ugexe/Perl6-Text--Levenshtein--Damerau"><img src="https://api.travis-ci.org/ugexe/Perl6-Text--Levenshtein--Damerau.svg?branch=master"></a>

=head1 Synopsis

    use Text::Levenshtein::Damerau;

    say dld('Neil','Niel'); # damerau levenstein distance
    # prints 1

    say ld('Neil','Niel'); # levenshtein distance
    prints 2

=head1 Description

Returns the true Levenshtein or Damerau Levenshtein edit distance of strings with adjacent transpositions. 

    use Text::Levenshtein::Damerau;

    my @names = 'John','Jonathan','Jose','Juan','Jimmy';
    my $name_mispelling = 'Jonh';

    my $dl = Text::Levenshtein::Damerau.new(
        max             => 0,       # default 
        targets         => @names,  # required
        sources         => [$name_mispelling]
    );

    say "Lets search for a 'John' but mistyped...";
    my %results =  $dl.get_results;

    # Display each source, target, and the distance
    for %results.kv -> $source, $targets {
        for $targets.kv -> $target, $dld {
            say "source:$source\ttarget:$target\tdld:" ~ ($dld // "<max exceeded>");
        }
    }

    # More info
    say "----------------------------";
    say "\$dl.best_distance:        {$dl.best_distance}";
    say "-";
    say "\$dl.targets:              {~$dl.targets}";
    say "\$dl.best_target:          {$dl.best_target}";
    say "-";
    say "\@names:                   {~@names}";

=head2 Routines

=over 8

=item * C<dld>

Damerau Levenshtein Distance (Levenshtein Distance including transpositions)

Arguments: $source, $target, $max?

I<$max distance. 0 = unlimited. Default = 0>

Returns: int that represents the edit distance between the two argument. Stops calculations and returns Int if max distance is set and reached if possible.


    use Text::Levenshtein::Damerau;
    say dld('AABBCC','AABCBCD');
    # prints 2

    # Max edit distance of 1
    say dld('AABBCC','AABCBCD',1); # distance is 2
    # prints Int

=item * C<ld>

Levenshtein Distance (no transpositions)

Arguments: $source, $target, $max?

I<$max distance. 0 = unlimited. Default = 0>

Returns: Int that represents edit distance between the two argument. Stops calculations and returns Int if max distance is set and reached if possible.

    use Text::Levenshtein::Damerau;
    say ld('AABBCC','AABCBCD');
    # prints 3

    # Max edit distance of 1
    # Uses regular Levenshtein distance (no transpositions)
    say ld('AABBCC','AABCBCD',1); # distance is 3
    # prints Int

=back

=head2 Methods

=over 8

=item * C<new>

Damerau Levenshtein Distance (Levenshtein Distance including transpositions)

Arguments: \@sources, \@targets, $max?

I<$max distance. 0 = unlimited. Default = 0>

Create a new object. For now, this is so you may call C<get_results> on it.

=item * C<get_results>

Generates %results and sets the following attributes:

    $.best_distance
    $.best_target
    $.best_source if @.sources.elems > 1
    %.results
    # %results{$source}{$target} = $distance_result

Returns: %.results

=back

=head2 Bugs

Please report bugs to:

L<https://github.com/ugexe/Perl6-Text--Levenshtein--Damerau/issues>

=head2 Author

Nick Logan L<nlogan@gmail.com>

=cut