NAME

       Sort::Key::Natural - fast natural sorting

SYNOPSIS

           use Sort::Key::Natural qw(natsort);

           my @data = qw(foo1 foo23 foo6 bar12 bar1
                         foo bar2 bar-45 foomatic b-a-r-45);

           my @sorted = natsort @data;

           print "@sorted\n";
           # prints:
           #   b-a-r-45 bar1 bar2 bar12 bar-45 foo foo1 foo6 foo23 foomatic

           use Sort::Key::Natural qw(natkeysort);

           my @objects = (...);
           my @sorted = natkeysort { $_->get_id } @objects;

DESCRIPTION

       This module extends the Sort::Key family of modules to support natural sorting.

       Under natural sorting, strings are split at word and number boundaries, and the resulting
       substrings are compared as follows:

       ·   numeric substrings are compared numerically

       ·   alphabetic substrings are compared lexically

       ·   numeric substrings come always before alphabetic substrings

       Spaces, symbols and non-printable characters are only considered for splitting the string
       into its parts but not for sorting. For instance "foo-bar-42" is broken in three
       substrings "foo", "bar" and 42 and after that the dashes are ignored.

       Note, that the sorting is case sensitive. To do a case insensitive sort you have to
       convert the keys explicitly:

         my @sorted = natkeysort { lc $_ } @data

       Also, once this module is loaded, the new type "natural" (or "nat") will be available from
       Sort::Key::Maker. For instance:

         use Sort::Key::Natural;
         use Sort::Key::Maker i_rnat_keysort => qw(integer -natural);

       creates a multikey sorter "i_rnat_keysort" accepting two keys, the first to be compared as
       an integer and the second in natural descending order.

       There is also an alternative set of natural sorting functions that recognize floating
       point numbers. They use the key type "natwf" (abreviation of "natural_with_floats").

   FUNCTIONS
       the functions that can be imported from this module are:

       natsort @data
           returns the elements of @data sorted in natural order.

       rnatsort @data
           returns the elements of @data sorted in natural descending order.

       natkeysort { CALC_KEY($_) } @data
           returns the elements on @array naturally sorted by the keys resulting from applying
           them "CALC_KEY".

       rnatkeysort { CALC_KEY($_) } @data
           is similar to "natkeysort" but sorts the elements in descending order.

       natsort_inplace @data
       rnatsort_inplace @data
       natkeysort_inplace { CALC_KEY($_) } @data
       rnatkeysort_inplace { CALC_KEY($_) } @data
           these functions are similar respectively to "natsort", "rnatsort", "natsortkey" and
           "rnatsortkey", but they sort the array @data in place.

       $key = mkkey_natural $string
           given $string, returns a key that can be compared lexicographically to another key
           obtained in the same manner, results in the same order as comparing the former strings
           as in the natural order.

           If the argument $key is not provided it defaults to $_.

       natwfsort @data
       rnatwfsort @data
       natkeywfsort { CALC_KEY($_) } @data
       rnatkeywfsort { CALC_KEY($_) } @data
       natwfsort_inplace @data
       rnatwfsort_inplace @data
       natkeywfsort_inplace { CALC_KEY($_) } @data
       rnatkeywfsort_inplace { CALC_KEY($_) } @data
       mkkey_natural_with_floats $key
           this ugly named set of functions perform in the same way as its s/natwf/nat/
           counterpart with the difference that they honor floating point numbers embeded inside
           the strings.

           In this context a floating point number is a string matching the regular expression
           "/[+\-]?\d+(\.\d*)?/". Note that numbers with an exponent part (i.e. "1.12E-12") are
           not recognized as such.

           Note also that numbers without an integer part (i.e. .2 or "-.12") are not supported
           either.

SEE ALSO

       Sort::Key, Sort::Key::Maker.

       Other module providing similar functionality is Sort::Naturally.

COPYRIGHT AND LICENSE

       Copyright (C) 2006, 2012 by Salvador Fandin~o, <sfandino@yahoo.com>.

       This library is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself, either Perl version 5.8.4 or, at your option, any later version of
       Perl 5 you may have available.