NAME

       Text::Levenshtein::Damerau - Damerau Levenshtein edit distance.

SYNOPSIS

               use Text::Levenshtein::Damerau;
               use warnings;
               use strict;

               my @targets = ('fuor','xr','fourrrr','fo');

               # Initialize Text::Levenshtein::Damerau object with text to compare against
               my $tld = Text::Levenshtein::Damerau->new('four');

               print $tld->dld($targets[0]);
               # prints 1

               my $tld = $tld->dld({ list => \@targets });
               print $tld->{'fuor'};
               # prints 1

               print $tld->dld_best_match({ list => \@targets });
               # prints fuor

               print $tld->dld_best_distance({ list => \@targets });
               # prints 1

               # or even more simply
               use Text::Levenshtein::Damerau qw/edistance/;
               use warnings;
               use strict;

               print edistance('Neil','Niel');
               # prints 1

DESCRIPTION

       Returns the true Damerau Levenshtein edit distance of strings with adjacent
       transpositions. Useful for fuzzy matching, DNA variation metrics, and fraud detection.

       Defaults to using Pure Perl Text::Levenshtein::Damerau::PP, but has an XS addon
       Text::Levenshtein::Damerau::XS for massive speed imrovements. Works correctly with utf8 if
       backend supports it; known to work with "Text::Levenshtein::Damerau::PP" and
       "Text::Levenshtein::Damerau::XS".

               use utf8;
               my $tld = Text::Levenshtein::Damerau->new('ⓕⓞⓤⓡ');
               print $tld->dld('ⓕⓤⓞⓡ');
               # prints 1

CONSTRUCTOR

   new
       Creates and returns a "Text::Levenshtein::Damerau" object. Takes a scalar with the text
       (source) you want to compare against.

               my $tld = Text::Levenshtein::Damerau->new('Neil');
               # Creates a new Text::Levenshtein::Damerau object $tld

METHODS

   $tld->dld
       Scalar Argument: Takes a string to compare with.

       Returns: an integer representing the edit distance between the source and the passed
       argument.

       Hashref Argument: Takes a hashref containing:

       •   list => \@array (array ref of strings to compare with)

       •   OPTIONAL max_distance => $int (only return results with $int distance or less).

       •   OPTIONAL backend => 'Some::Module::its_function' Any module that will take 2 arguments
           and returns an int. If the module fails to load, the function doesn't exist, or the
           function doesn't return a number when passed 2 strings, then "backend" remains
           unchanged.

                   # Override defaults and use Text::Levenshtein::Damerau::PP's pp_edistance()
                   $tld->dld({ list=> \@list, backend => 'Text::Levenshtein::Damerau::PP::pp_edistance');

                   # Override defaults and use Text::Levenshtein::Damerau::XS's xs_edistance()
                   use Text::Levenshtein::Damerau;
                   requires Text::Levenshtein::Damerau::XS;
                   ...
                   $tld->dld({ list=> \@list, backend => 'Text::Levenshtein::Damerau::XS::xs_edistance');

       Returns: hashref with each word from the passed list as keys, and their edit distance (if
       less than max_distance, which is unlimited by default).

               my $tld = Text::Levenshtein::Damerau->new('Neil');
               print $tld->dld( 'Niel' );
               # prints 1

               #or if you want to check the distance of various items in a list

               my @names_list = ('Niel','Jack');
               my $tld = Text::Levenshtein::Damerau->new('Neil');
               my $d_ref = $tld->dld({ list=> \@names_list }); # pass a list, returns a hash ref
               print $d_ref->{'Niel'}; #prints 1
               print $d_ref->{'Jack'}; #prints 4

   $tld->dld_best_match
       Argument: an array reference of strings.

       Returns: the string with the smallest edit distance between the source and the array of
       strings passed.

       Takes distance of $tld source against every item in @targets, then returns the string of
       the best match.

               my $tld = Text::Levenshtein::Damerau->new('Neil');
               my @name_spellings = ('Niel','Neell','KNiel');
               print $tld->dld_best_match({ list=> \@name_spellings });
               # prints Niel

   $tld->dld_best_distance
       Arguments: an array reference of strings.

       Returns: the smallest edit distance between the source and the array reference of strings
       passed.

       Takes distance of $tld source against every item in the passed array, then returns the
       smallest edit distance.

               my $tld = Text::Levenshtein::Damerau->new('Neil');
               my @name_spellings = ('Niel','Neell','KNiel');
               print $tld->dld_best_distance({ list => \@name_spellings });
               # prints 1

EXPORTABLE METHODS

   edistance
       Arguments: source string and target string.

       •   OPTIONAL 3rd argument int (max distance; only return results with $int distance or
           less). 0 = unlimited. Default = 0.

       Returns: int that represents the edit distance between the two argument. -1 if max
       distance is set and reached.

       Wrapper function to take the edit distance between a source and target string. It will
       attempt to use, in order:

       •   Text::Levenshtein::Damerau::XS xs_edistance

       •   Text::Levenshtein::Damerau::PP pp_edistance

               use Text::Levenshtein::Damerau qw/edistance/;
               print edistance('Neil','Niel');
               # prints 1

SEE ALSO

       •   <https://github.com/ugexe/Text--Levenshtein--Damerau> Repository

       •   <http://en.wikipedia.org/wiki/Damerau%E2%80%93Levenshtein_distance> Damerau
           levenshtein explanation

       •   Text::Fuzzy Regular levenshtein distance

BUGS

       Please report bugs to:

       <https://rt.cpan.org/Public/Dist/Display.html?Name=Text-Levenshtein-Damerau>

AUTHOR

       Nick Logan <ug@skunkds.com>

LICENSE AND COPYRIGHT

       This library is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.