/ 
List-Util-Uniq-0.007
River stage three • 4 direct dependents • 273 total dependents
/ List::Util::Uniq

NAME

List::Util::Uniq - List utilities related to finding unique items

VERSION

This document describes version 0.007 of List::Util::Uniq (from Perl distribution List-Util-Uniq), released on 2023-08-14.

SYNOPSIS

use List::Util::Uniq qw(
    is_monovalued
    is_monovalued_ci
    is_uniq
    is_uniq_ci
    uniq_adj
    uniq_adj_ci
    uniq_ci
    dupe
    dupeint
    dupenum
    dupestr
    dupe_ci
);

$res = is_monovalued(qw/a a a/); # => 1
$res = is_monovalued(qw/a b a/); # => 0

$res = is_monovalued_ci(qw/a a A/); # => 1
$res = is_monovalued_ci(qw/a b A/); # => 0

$res = is_uniq(qw/a b a/); # => 0
$res = is_uniq(qw/a b c/); # => 1

$res = is_uniq_ci(qw/a b A/); # => 0
$res = is_uniq_ci(qw/a b c/); # => 1

@res = uniq_adj(1, 4, 4, 3, 1, 1, 2); # => (1, 4, 3, 1, 2)

@res = uniq_adj_ci("a", "b", "B", "c", "a"); # => ("a", "b", "c", "a")

@res = uniq_ci("a", "b", "B", "c", "a"); #  => ("a", "b", "c")

@res = dupe("a","b","a","a","b","c"); #  => ("a","a","b")
@res = dupeint(1,1.2,1.3,2); #  => (1.2,1.3)
@res = dupenum(1,2,1,1,2,3); #  => (1,1,2)
@res = dupenum("a",0,0.0,1); #  => (0,0.0), because "a" becomes 0 numerically
@res = dupestr("a","b","a","a","b","c"); # => ("a","a","b")

@res = dupe_ci("a", "b", "B", "c", "a"); #  => ("B", "a")

DESCRIPTION

This module supplements List::Util with functions related to list item's uniqueness.

FUNCTIONS

None exported by default but exportable.

uniq_adj

Usage:

my @uniq = uniq_adj(@list);

Remove adjacent duplicates from list, i.e. behave more like Unix utility's uniq instead of List::Util's uniq function. Uses string equality test (the eq operator).

uniq_adj_ci

Like "uniq_adj" except case-insensitive.

uniq_ci

Like List::Util' uniq (uniqstr) except case-insensitive.

is_uniq

Usage:

my $is_uniq = is_uniq(@list);

Return true when the values in @list is unique (compared string-wise). In theory, knowing whether a list has unique values is faster using this function compared to doing:

my @uniq = uniq(@list);
@uniq == @list;

because of short-circuiting.

is_uniq_ci

Like "is_uniq" except case-insensitive.

is_monovalued

Usage:

my $is_monovalued = is_monovalued(@list);

Examples:

is_monovalued(qw/a b c/); # => 0
is_monovalued(qw/a a a/); # => 1

Return true if @list contains only a single value. Returns true for empty list. Undef is coerced to empty string, so is_monovalued(undef) and is_monovalued(undef, undef) return true.

is_monovalued_ci

Like "is_monovalued" except case-insensitive.

dupe

See "dupestr".

dupeint

Like "dupestr" but the values are compared as integers. If you only want to list each duplicate elements once, you can do:

@uniq_dupes = uniqint(dupeint(@list));

where uniqint can be found in List::Util, but the pure-perl version is also provided by this module, for convenience.

dupenum

Like "dupestr" but the values are compared numerically. If you only want to list each duplicate elements once, you can do:

@uniq_dupes = uniqnum(dupenum(@list));

where uniqnum can be found in List::Util, but the pure-perl version is also provided by this module, for convenience.

dupestr

Usage:

@dupes = dupestr(@list);

Return duplicate elements (the second and subsequence occurrences of each element) in @list. If you only want to list each duplicate elements once, you can do:

@uniq_dupes = uniqstr(dupestr(@list));

where uniqstr can be found in List::Util, but the pure-perl version is also provided by this module, for convenience.

dupe_ci

Like "dupe" except case-insensitive.

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/List-Util-Uniq.

SOURCE

Source repository is at https://github.com/perlancar/perl-List-Util-Uniq.

SEE ALSO

List::Util

Other List::Util::* modules.

AUTHOR

perlancar <perlancar@cpan.org>

CONTRIBUTING

To contribute, you can send patches by email/via RT, or send pull requests on GitHub.

Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then test via:

% prove -l

If you want to build the distribution (e.g. to try to install it locally on your system), you can install Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond that are considered a bug and can be reported to me.

COPYRIGHT AND LICENSE

This software is copyright (c) 2023, 2018 by perlancar <perlancar@cpan.org>.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=List-Util-Uniq

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.