NAME
Sort::Naturally::XS - Perl extension for human-friendly ("natural") sort order
SYNOPSIS
use Sort::Naturally::XS;
my @mixed_list = qw/test21 test20 test10 test11 test2 test1/;
my @result = nsort(@mixed_list); # @result is: test1 test2 test10 test11 test20 test21
@result = sort ncmp @mixed_list; # same, but use standard sort function
@result = sort {ncmp($a, $b)} @mixed_list; # same as ncmp, but argument pass explicitly
DESCRIPTION
Natural sort order is an ordering of mixed strings (consist of characters and digits) in alphabetical order, except that digital parts are ordered as numbers. Natural sorting can be considered as a replacement of a standard machine-oriented alphabetical sorting, because it is more convenient for human understanding. For example, the following list:
test21 test20 test10 test11 test2 test1
after performing a standard machine-oriented alphabetical sorting, will be as follows:
test1 test10 test11 test2 test20 test21
The sequence appears unnatural, because test10 and test11 come before test2. On the other hand, natural sorting gives a human-friendly sequence:
test1 test2 test10 test11 test20 test21
now test2 comes before test10 and test11.
METHODS
ncmp(LEFT, RIGHT)
-
Replacement of the
cmp
standard operator. LEFT and RIGHT variables are presented for comparison. Returns 1 if LEFT should come before RIGHT, -1 if RIGHT should come before LEFT and 0 if LEFT and RIGHT match.# sort @list naturally, support in latest perl versions my @result = sort ncmp @list; # same, but arguments pass explicitly @result = sort {ncmp($a, $b)} @list; # more complex example, sort ARRAY of HASH refs by key 'foo' in descending order @result = sort {ncmp($b->{foo}, $a->{foo})} @list;
nsort(LIST)
-
In list context returns a LIST sorted copy.
my @result = nsort(@list);
sorted(ARRAY_REF, KWARGS)
-
Returns an ARRAY ref to a sorted list. First argument is an ARRAY ref to the source list, followed by keyword arguments, such as
reverse
andlocale
. Ifreverse
is true the source list is sorted in reverse order. Iflocale
is specified, the sorting will be performed according to the locale aware settings.use Sort::Naturally::XS qw/sorted/; my $result = sorted($list); $result = sorted($list, reverse => 1); # $list will be sorted in descending order $result = sorted($list, locale => 'en_US.utf8'); # $list will be sorted according to en_US.utf8 locale
LOCALE AWARE SORTING
By default the sort function sorts according to a standard C locale or, if a use locale
pragma is in effect, according to OS settings, which can be changed with the help of the setlocale
function. The use of both use locale
and setlocale
has no effect on ncmp
and nsort
. The following example demonstrates this behavior:
use POSIX;
use Sort::Naturally::XS;
my @list = ('a.'.'c', 'A'..'B');
my @result_std = sort @list;
my @result_ncmp = sort {ncmp($a, $b)} @list;
# @result_std contains A, B, C, a, b, c
# @result_ncmp contains A, B, C, a, b, c
use locale;
# assumed that current locale is en_US.utf8
@result_std = sort @list;
@result_ncmp = sort {ncmp($a, $b)} @list;
# @result_std contains a, A, b, B, c, C
# @result_ncmp contains A, B, C, a, b, c
setlocale(POSIX::LC_ALL, 'en_CA.utf8');
@result_std = sort @list;
@result_ncmp = sort {ncmp($a, $b)} @list;
# @result_std contains A, a, B, b, C, c
# @result_ncmp contains A, B, C, a, b, c
To be able to sort a list with an arbitrary locale it is necessary to use the sorted
function with a locale
keyword argument:
use Sort::Naturally::XS qw/sorted/;
my $list = ['a.'.'c', 'A'..'B'];
my $result_us = sorted($list, locale => 'en_US.utf8');
# $result_us contains a, A, b, B, c, C
my $result_ca = sorted($list, locale => 'en_CA.utf8');
# $result_ca contains A, a, B, b, C, c
Note: due to the complexity of a cross-platform support, a locale aware sorting is guaranteed on Unix-like operating systems only.
EXPORT
By default the module exports ncmp
and nsort
subroutines.
BENCHMARK
require Benchmark;
require Sort::Naturally::XS;
require Sort::Naturally;
my @list = (
'H4', 'T25', 'H5', 'T27', 'H8', 'T30', 'HEX', 'T35', 'M10', 'T4', 'M12', 'T40', 'M13', 'T45', 'M14',
'T47', 'M16', 'T5', 'M4', 'T50', 'M5', 'T55', 'M6', 'T6', 'M7', 'T60', 'M8', 'T7', 'M9', 'T70', 'Ph0',
'T8', 'Ph1', 'T9', 'Ph2', 'TT10', 'Ph3', 'TT15', 'Ph4', 'TT20', 'Pz0', 'TT25', 'Pz1', 'TT27', 'Pz2',
'TT30', 'Pz3', 'TT40', 'Pz4', 'TT45', 'R10', 'TT50', 'R12', 'TT55', 'R13', 'TT6', 'R14', 'TT60', 'R5',
'TT7', 'R6', 'TT70', 'R7', 'TT8', 'R8', 'TT9', 'S', 'TX', 'Sl', 'XZN', 'T10', 'T15', 'T20'
);
Benchmark::cmpthese(-3, {
my => sub { Sort::Naturally::XS::nsort(@list) },
other => sub { Sort::Naturally::nsort(@list) },
});
# Rate other my
# other 561/s -- -97%
# my 20693/s 3588% --
Benchmark::cmpthese(-10, {
std => sub { sort @list },
other => sub { sort {Sort::Naturally::ncmp($a, $b)} @list },
my => sub { sort {Sort::Naturally::XS::ncmp($a, $b)} @list },
});
# Rate other std my
# other 7977106/s -- -3% -5%
# std 8232321/s 3% -- -2%
# my 8426303/s 6% 2% --
NOTES
- There are differences in sorting outcomes compared with the Sort::Naturally module. Capital letters always come before lower case letters, digits always come before letters.
-
9x 14 foo fooa foolio Foolio foo12 foo12a Foo12a foo12z foo13a # Sort::Naturally 9x 14 Foo12a Foolio foo foo12 foo12a foo12z foo13a fooa foolio # Sort::Naturally::XS
- Due to a significant overhead it is not recommended for sorting lists consisting of letters or digits only.
- Due to the complexity of a cross-platform support, a locale aware sorting is guaranteed on Unix-like operating systems only.
SEE ALSO
AUTHOR
Sergey Yurzin, jurzin.s@gmail.com
COPYRIGHT AND LICENSE
Copyright (C) 2017 by Sergey Yurzin
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.18.2 or, at your option, any later version of Perl 5 you may have available.