List::Util(3perl)

๐ŸŒธ List::Util (3perl) ๐ŸŒธ

okay bestie, so this page is from the Perl Programmers Reference Guide, section 3perl, and it's literally called List::Util. It is SO good. It's a whole bag of general-utility list subroutines, like the kind of little guys you reach for every single day and go "why is this not just, like, built in". Well. It IS. Come here ๐Ÿ’–


โœจ NAME โœจ

List::Util โ€” a selection of general-utility list subroutines ๐Ÿซถ


๐Ÿ’… SYNOPSIS ๐Ÿ’…

use List::Util qw(
  reduce any all none notall first reductions

  max maxstr min minstr product sum sum0

  pairs unpairs pairkeys pairvalues pairfirst pairgrep pairmap

  shuffle uniq uniqint uniqnum uniqstr head tail zip mesh
);

look at that list. iconique. no cap.


๐Ÿฆ‹ DESCRIPTION ๐Ÿฆ‹

So List::Util is literally just a lil collection of subroutines that people kept asking for in perl core, right? But the usage wasn't quite high enough to justify making them actual keywords, and each one is so tiny that shipping them as separate individual extensions would be wasteful. So they all live here together. roommates. ๐Ÿ 

and by default? List::Util does not export any subroutines. not a single one. you gotta ask. she's not gonna just show up uninvited ๐Ÿ’…


๐Ÿ‘‘ LIST-REDUCTION FUNCTIONS ๐Ÿ‘‘

these are a whole vibe. every single function in this little family takes a given block of code and applies it to a list of values.

๐ŸŒˆ reduce

$result = reduce { BLOCK } @list

okay so reduce takes @list and squishes it down by calling BLOCK in scalar context over and over, setting $a and $b every single time. the very first call gets $a and $b set to the first two elements of the list. every call after that sets $a to the result of the previous call, and $b to the next element in the list. it's givingโ€ฆ a relay race ๐Ÿƒโ€โ™€๏ธ

it returns the result of the last call to BLOCK. if @list is empty then undef is returned. and if @list only has one element? that element is returned and BLOCK is not even executed. she said no thanks ๐Ÿ’€

the following examples all demonstrate how reduce could be used to implement the other list-reduction functions in this module. (they are not in fact implemented like this โ€” they're done in a more efficient manner in individual C functions. flex.)

$foo = reduce { defined($a)            ? $a :
                $code->(local $_ = $b) ? $b :
                                         undef } undef, @list # first

$foo = reduce { $a > $b ? $a : $b } 1..10       # max
$foo = reduce { $a gt $b ? $a : $b } 'A'..'Z'   # maxstr
$foo = reduce { $a < $b ? $a : $b } 1..10       # min
$foo = reduce { $a lt $b ? $a : $b } 'aa'..'zz' # minstr
$foo = reduce { $a + $b } 1 .. 10               # sum
$foo = reduce { $a . $b } @bar                  # concat

$foo = reduce { $a || $code->(local $_ = $b) } 0, @bar   # any
$foo = reduce { $a && $code->(local $_ = $b) } 1, @bar   # all
$foo = reduce { $a && !$code->(local $_ = $b) } 1, @bar  # none
$foo = reduce { $a || !$code->(local $_ = $b) } 0, @bar  # notall
   # Note that these implementations do not fully short-circuit
okay important bestie moment: if your algorithm requires that reduce produce an identity value, then make sure you always pass that identity value as the first argument, so undef doesn't get returned on you. protect yourself.
$foo = reduce { $a + $b } 0, @values;             # sum with 0 identity value

those example code blocks above also lowkey hint at how to use reduce to build a more efficient combined version of one of these basic functions plus a map block. like, say you wanna find the total length of all the strings in a list. you could do:

$total = sum map { length } @strings;

but that builds a whole temporary list of integer values as long as your original list of strings, just to squish it back down to one value again. so wasteful bestie ๐Ÿ˜ญ we can compute the exact same result more efficiently by using reduce with a code block that accumulates lengths, like this instead:

$total = reduce { $a + length $b } 0, @strings

the other scalar-returning list reduction functions are all just specialisations of this generic idea. they're all reduce's daughters ๐Ÿ’–

๐ŸŒธ reductions

@results = reductions { BLOCK } @list

Since version 1.54.

just like reduce, except she also hands you the intermediate values along with the final result. as before, $a is set to the first element of the given list, and then BLOCK gets called once for each remaining item in the list (that item goes into $b), with the result being captured for return and becoming the new value for $a. double duty. main character energy.

the returned list begins with the initial value for $a, followed by each return value from the block, in order. the final value of the result will be identical to what reduce would have returned given the same block and list. fr fr.

reduce     { "$a-$b" }  "a".."d"    # "a-b-c-d"
reductions { "$a-$b" }  "a".."d"    # "a", "a-b", "a-b-c", "a-b-c-d"

๐ŸŒŸ any

my $bool = any { BLOCK } @list;

Since version 1.33.

similar to grep in that it evaluates BLOCK setting $_ to each element of @list in turn. any returns true if any element makes BLOCK return a true value. if BLOCK never returns true, or @list was empty, then it returns false.

lots of cases where you'd use grep in a conditional can be written with any instead, because any can short-circuit after the first true result. she doesn't waste time. she knows what she wants. ๐Ÿ’…

if( any { length > 10 } @strings ) {
    # at least one string has more than 10 characters
}
Note: due to XS issues the block passed may be able to access the outer @_ directly. this is not intentional and will break under debugger. so. be aware ๐Ÿ’€

๐ŸŽ€ all

my $bool = all { BLOCK } @list;

Since version 1.33.

like any, except it requires all elements of @list to make BLOCK return true. if any element returns false, then it returns false. if BLOCK never returns false, or @list was empty, then it returns true. everyone has to show up to the function, no excuses.

Note: due to XS issues the block passed may be able to access the outer @_ directly. this is not intentional and will break under debugger. yes, again. it's a whole thing ๐Ÿ™ˆ

๐Ÿงš none / notall

my $bool = none { BLOCK } @list;

my $bool = notall { BLOCK } @list;

Since version 1.33.

similar to any and all, but with the return sense inverted. none returns true only if no value in @list causes BLOCK to return true. and notall returns true only if not all of the values do. flip it, reverse it, slay โœจ

Note: due to XS issues the block passed may be able to access the outer @_ directly. this is not intentional and will break under debugger. yeah this note is everywhere. it's iconic at this point.

๐Ÿ“ first

my $val = first { BLOCK } @list;

similar to grep in that it evaluates BLOCK setting $_ to each element of @list in turn. first returns the first element where the result from BLOCK is a true value. if BLOCK never returns true, or @list was empty, then undef is returned. she's just looking for the one. ๐Ÿฅบ

$foo = first { defined($_) } @list    # first defined value in @list
$foo = first { $_ > $value } @list    # first value in @list which
                                      # is greater than $value

๐Ÿ”ฅ max

my $num = max @list;

returns the entry in the list with the highest numerical value. if the list is empty then undef is returned. she's the tallest in the group photo, numerically speaking.

$foo = max 1..10                # 10
$foo = max 3,9,12               # 12
$foo = max @bar, @baz           # whatever

โญ maxstr

my $str = maxstr @list;

similar to max, but treats all the entries in the list as strings and returns the highest string as defined by the gt operator. if the list is empty then undef is returned.

$foo = maxstr 'A'..'Z'          # 'Z'
$foo = maxstr "hello","world"   # "world"
$foo = maxstr @bar, @baz        # whatever

๐Ÿฆ‹ min

my $num = min @list;

similar to max but returns the entry in the list with the lowest numerical value. if the list is empty then undef is returned.

$foo = min 1..10                # 1
$foo = min 3,9,12               # 3
$foo = min @bar, @baz           # whatever

๐Ÿ’œ minstr

my $str = minstr @list;

similar to min, but treats all the entries in the list as strings and returns the lowest string as defined by the lt operator. if the list is empty then undef is returned.

$foo = minstr 'A'..'Z'          # 'A'
$foo = minstr "hello","world"   # "hello"
$foo = minstr @bar, @baz        # whatever

๐ŸŒˆ product

my $num = product @list;

Since version 1.35.

returns the numerical product of all the elements in @list. if @list is empty then 1 is returned. multiply multiply multiply โœ–๏ธ

$foo = product 1..10            # 3628800
$foo = product 3,9,12           # 324

๐Ÿ’– sum

my $num_or_undef = sum @list;

returns the numerical sum of all the elements in @list. for backwards compatibility, if @list is empty then undef is returned. yes bestie, undef, for backwards compatibility. it's a legacy thing, we respect it ๐Ÿ‘‘

$foo = sum 1..10                # 55
$foo = sum 3,9,12               # 24
$foo = sum @bar, @baz           # whatever

โœจ sum0

my $num = sum0 @list;

Since version 1.26.

similar to sum, except this one returns 0 when given an empty list, rather than undef. the upgrade. the glow-up. the version of you that goes to therapy ๐Ÿซถ

๐Ÿ’– KEY/VALUE PAIR LIST FUNCTIONS ๐Ÿ’–

okay bestie, this whole little crew was inspired by List::Pairwise, and every single one of them consumes an even-sized list of pairs. those pairs can be key/value associations straight out of a hash, or literally just a list of values โ€” the functions do not care. they all preserve the original ordering of the pairs, they will not get confused by multiple pairs sharing the same "key" value, and they don't even require the first item of each pair to be a plain string. no cap. ๐Ÿ’…

๐Ÿšจ NOTE: at the time of writing, the following pair* functions that take a block do not modify the value of $_ inside the block โ€” instead they operate using the $a and $b globals. this has turned out to be a poor design, because it precludes the ability to provide a pairsort function. the better move would be to pass pair-like objects as 2-element array references in $_, in a style similar to the return value of the pairs function. at some future version this behaviour may be added.

until then, users are alerted NOT to rely on the value of $_ remaining unmodified between the outside and the inside of the control block. in particular, the following example is UNSAFE:

my @kvlist = ...

foreach (qw( some keys here )) {
   my @items = pairgrep { $a eq $_ } @kvlist;
   ...
}

instead, write this using a lexical variable:

foreach my $key (qw( some keys here )) {
   my @items = pairgrep { $a eq $key } @kvlist;
   ...
}

โœจ pairs โœจ

my @pairs = pairs @kvlist;

since version 1.29. ๐ŸŽ€

a convenient shortcut to operating on even-sized lists of pairs โ€” this function returns a list of ARRAY references, each containing two items from the given list. it's a more efficient version of

@pairs = pairmap { [ $a, $b ] } @kvlist

it is most convenient to use in a foreach loop, like:

foreach my $pair ( pairs @kvlist ) {
   my ( $key, $value ) = @$pair;
   ...
}

since version 1.39 these ARRAY references are blessed objects, recognising the two methods key and value. the following code is equivalent:

foreach my $pair ( pairs @kvlist ) {
   my $key   = $pair->key;
   my $value = $pair->value;
   ...
}

since version 1.51 they also have a TO_JSON method to ease serialisation. slay. ๐ŸŒˆ

โœจ unpairs โœจ

my @kvlist = unpairs @pairs

since version 1.42.

the inverse function to pairs; this function takes a list of ARRAY references containing two elements each, and returns a flattened list of the two values from each of the pairs, in order. notionally equivalent to

my @kvlist = map { @{$_}[0,1] } @pairs

except that it's implemented more efficiently internally. specifically, for any input item it will extract exactly two values for the output list; using undef if the input array references are short. ๐Ÿ‘‘

between pairs and unpairs, a higher-order list function can be used to operate on the pairs as single scalars; such as the following near-equivalents of the other pair* higher-order functions:

@kvlist = unpairs grep { FUNC } pairs @kvlist
# Like pairgrep, but takes $_ instead of $a and $b

@kvlist = unpairs map { FUNC } pairs @kvlist
# Like pairmap, but takes $_ instead of $a and $b

note however that these versions will not behave as nicely in scalar context. ๐Ÿ˜ญ

finally, this technique can be used to implement a sort on a keyvalue pair list; e.g.:

@kvlist = unpairs sort { $a->key cmp $b->key } pairs @kvlist

โœจ pairkeys โœจ

my @keys = pairkeys @kvlist;

since version 1.29.

a convenient shortcut to operating on even-sized lists of pairs โ€” this function returns a list of the first values of each of the pairs in the given list. it's a more efficient version of

@keys = pairmap { $a } @kvlist

โœจ pairvalues โœจ

my @values = pairvalues @kvlist;

since version 1.29.

a convenient shortcut to operating on even-sized lists of pairs โ€” this function returns a list of the second values of each of the pairs in the given list. it's a more efficient version of

@values = pairmap { $b } @kvlist

โœจ pairgrep โœจ

my @kvlist = pairgrep { BLOCK } @kvlist;

my $count = pairgrep { BLOCK } @kvlist;

since version 1.29.

similar to perl's grep keyword, but it interprets the given list as an even-sized list of pairs. it invokes the BLOCK multiple times, in scalar context, with $a and $b set to successive pairs of values from the @kvlist. ๐Ÿซถ

returns an even-sized list of those pairs for which the BLOCK returned true in list context, or the count of the number of pairs in scalar context. (note, therefore, in scalar context that it returns a number half the size of the count of items it would have returned in list context.)

@subset = pairgrep { $a =~ m/^[[:upper:]]+$/ } @kvlist

as with grep aliasing $_ to list elements, pairgrep aliases $a and $b to elements of the given list. any modifications of it by the code block will be visible to the caller. ๐Ÿ‘€

โœจ pairfirst โœจ

my ( $key, $val ) = pairfirst { BLOCK } @kvlist;

my $found = pairfirst { BLOCK } @kvlist;

since version 1.30.

similar to the first function, but it interprets the given list as an even-sized list of pairs. it invokes the BLOCK multiple times, in scalar context, with $a and $b set to successive pairs of values from the @kvlist.

returns the first pair of values from the list for which the BLOCK returned true in list context, or an empty list if no such pair was found. in scalar context it returns a simple boolean value, rather than either the key or the value found. ๐Ÿ’€

( $key, $value ) = pairfirst { $a =~ m/^[[:upper:]]+$/ } @kvlist

as with grep aliasing $_ to list elements, pairfirst aliases $a and $b to elements of the given list. any modifications of it by the code block will be visible to the caller.

โœจ pairmap โœจ

my @list = pairmap { BLOCK } @kvlist;

my $count = pairmap { BLOCK } @kvlist;

since version 1.29.

similar to perl's map keyword, but it interprets the given list as an even-sized list of pairs. it invokes the BLOCK multiple times, in list context, with $a and $b set to successive pairs of values from the @kvlist.

returns the concatenation of all the values returned by the BLOCK in list context, or the count of the number of items that would have been returned in scalar context. ๐Ÿ”ฅ

@result = pairmap { "The key $a has value $b" } @kvlist

as with map aliasing $_ to list elements, pairmap aliases $a and $b to elements of the given list. any modifications of it by the code block will be visible to the caller.

see "KNOWN BUGS" for a known-bug with pairmap, and a workaround. ๐Ÿฉน

โœจ OTHER FUNCTIONS โœจ

๐ŸŽฒ shuffle

my @values = shuffle @values;

okay so this one literally just hands you back your values in a random order. that's it. that's the whole vibe. chaos but cute ๐Ÿ’…

@cards = shuffle 0..51      # 0..51 in a random order

heads up bestie: this function is affected by the $RAND variable. ๐Ÿ‘€


๐ŸŽ€ sample

my @items = sample $count, @values

Since version 1.54.

randomly picks out the given number of elements from the input list. and like โ€” any given position in the input list will be selected at most once. no double-dipping, we don't do that here ๐Ÿซถ

if there are fewer than $count items in the list, then the function will return once all of them have been randomly selected; effectively it behaves similarly to shuffle. basically if you ask for more than exists it's like "okay bestie, you get everything, shuffled" โœจ

this function is affected by the $RAND variable too. ๐ŸŒˆ


๐Ÿฆ‹ uniq

my @subset = uniq @values

Since version 1.45.

filters a list of values to remove subsequent duplicates, judged by a DWIM-ish string equality or undef test. it preserves the order of unique elements, and retains the first value of any duplicate set. first come first served, periodt ๐Ÿ‘‘

my $count = uniq @values

in scalar context, returns the number of elements that would have been returned as a list. ๐Ÿงฎ

the undef value is treated by this function as distinct from the empty string, and no warning will be produced. it is left as-is in the returned list. subsequent undef values are still considered identical to the first, and will be removed. so like, the first undef is the moment, the rest are just copies ๐Ÿ’€


๐Ÿ”ข uniqint

my @subset = uniqint @values

Since version 1.55.

filters a list of values to remove subsequent duplicates, judged by an integer numerical equality test. preserves the order of unique elements, and retains the first value of any duplicate set. values in the returned list will be coerced into integers. ๐ŸŽฏ

my $count = uniqint @values

in scalar context, returns the number of elements that would have been returned as a list.

ngl, note that undef is treated much as other numerical operations treat it; it compares equal to zero but additionally produces a warning if such warnings are enabled (use warnings 'uninitialized';). in addition, an undef in the returned list is coerced into a numerical zero, so that the entire list of values returned by uniqint are well-behaved as integers. glow up fr ๐Ÿ’…


๐Ÿ”ข uniqnum

my @subset = uniqnum @values

Since version 1.44.

filters a list of values to remove subsequent duplicates, judged by a numerical equality test. preserves the order of unique elements, and retains the first value of any duplicate set. โœจ

my $count = uniqnum @values

in scalar context, returns the number of elements that would have been returned as a list.

note that undef is treated much as other numerical operations treat it; it compares equal to zero but additionally produces a warning if such warnings are enabled (use warnings 'uninitialized';). in addition, an undef in the returned list is coerced into a numerical zero, so that the entire list of values returned by uniqnum are well-behaved as numbers.

โš ๏ธ also note that multiple IEEE NaN values are treated as duplicates of each other, regardless of any differences in their payloads, and despite the fact that 0+'NaN' == 0+'NaN' yields false. NaN said "we're all the same actually" and honestly? iconic of it ๐Ÿ˜ญ

๐ŸŒธ uniqstr

my @subset = uniqstr @values

Since version 1.45.

filters a list of values to remove subsequent duplicates, judged by a string equality test. preserves the order of unique elements, and retains the first value of any duplicate set. ๐ŸŽ€

my $count = uniqstr @values

in scalar context, returns the number of elements that would have been returned as a list.

note that undef is treated much as other string operations treat it; it compares equal to the empty string but additionally produces a warning if such warnings are enabled (use warnings 'uninitialized';). in addition, an undef in the returned list is coerced into an empty string, so that the entire list of values returned by uniqstr are well-behaved as strings. slay ๐ŸŒˆ


my @values = head $size, @list;

Since version 1.50.

returns the first $size elements from @list. if $size is negative, returns all but the last $size elements from @list. (yes, negative size means "chop the end off", lowkey unhinged but we love her)

@result = head 2, qw( foo bar baz );
# foo, bar

@result = head -2, qw( foo bar baz );
# foo

๐Ÿš tail

my @values = tail $size, @list;

Since version 1.50.

returns the last $size elements from @list. if $size is negative, returns all but the first $size elements from @list.

@result = tail 2, qw( foo bar baz );
# bar, baz

@result = tail -2, qw( foo bar baz );
# baz

๐Ÿงš zip

my @result = zip [1..3], ['a'..'c'];
# [1, 'a'], [2, 'b'], [3, 'c']

Since version 1.56.

returns a list of array references, composed of elements from the given list of array references. each array in the returned list is composed of elements at that corresponding position from each of the given input arrays. if any input arrays run out of elements before others, then undef will be inserted into the result to fill in the gaps. ๐Ÿ•ณ๏ธโœจ

the zip function is particularly handy for iterating over multiple arrays at the same time with a foreach loop, taking one element from each:

foreach ( zip \@xs, \@ys, \@zs ) {
    my ($x, $y, $z) = @$_;
    ...
}
๐Ÿ“ข NOTE to users of List::MoreUtils: This function does not behave the same as List::MoreUtils::zip, but is actually a non-prototyped equivalent to List::MoreUtils::zip_unflatten. This function does not apply a prototype, so make sure to invoke it with references to arrays. bestie please, references. ๐Ÿ™

for a function similar to the zip function from List::MoreUtils, see mesh. (scroll down, she's right there ๐Ÿ’–)

my @result = zip_shortest ...

a variation of the function that differs in how it behaves when given input arrays of differing lengths. zip_shortest will stop as soon as any one of the input arrays runs out of elements, discarding any remaining unused values from the others. like she said "we're done here" and meant it ๐Ÿ’…

my @result = zip_longest ...

zip_longest is an alias to the zip function, provided simply to be explicit about that behaviour as compared to zip_shortest. it's the same thing, just wearing a label ๐Ÿท๏ธ


๐Ÿ“ mesh

my @result = mesh [1..3], ['a'..'c'];
# (1, 'a', 2, 'b', 3, 'c')

Since version 1.56.

returns a list of items collected from elements of the given list of array references. each section of items in the returned list is composed of elements at the corresponding position from each of the given input arrays. if any input arrays run out of elements before others, then undef will be inserted into the result to fill in the gaps.

this is similar to zip, except that all of the ranges in the result are returned in one long flattened list, instead of being bundled into separate arrays. no little bundles, just one big gorgeous stream โœจ

because it returns a flat list of items, the mesh function is particularly useful for building a hash out of two separate arrays of keys and values:

my %hash = mesh \@keys, \@values;

my $href = { mesh \@keys, \@values };
๐Ÿ“ข NOTE to users of List::MoreUtils: This function is a non-prototyped equivalent to List::MoreUtils::mesh or List::MoreUtils::zip (themselves aliases of each other). This function does not apply a prototype, so make sure to invoke it with references to arrays. again: references, bestie ๐Ÿซถ
my @result = mesh_shortest ...

my @result = mesh_longest ...

these variations are similar to those of zip, in that they differ in behaviour when one of the input lists runs out of elements before the others. ๐ŸŒˆ


โš™๏ธ CONFIGURATION VARIABLES โš™๏ธ

๐ŸŽฐ $RAND

local $List::Util::RAND = sub { ... };

Since version 1.54.

this package variable is used by code which needs to generate random numbers (such as the shuffle and sample functions). if set to a CODE reference it provides an alternative to perl's builtin rand() function. when a new random number is needed this function will be invoked with no arguments and is expected to return a floating-point value, of which only the fractional part will be used. so like, bring your own chaos source, we'll just take the decimal bit ๐ŸŽฒ๐Ÿ’–


๐Ÿ’€ KNOWN BUGS ๐Ÿ’€

RT #95409

<https://rt.cpan.org/Ticket/Display.html?id=95409>

if the block of code given to pairmap contains lexical variables that are captured by a returned closure, and the closure is executed after the block has been re-used for the next iteration, these lexicals will not see the correct values. for example:

 my @subs = pairmap {
    my $var = "$a is $b";
    sub { print "$var\n" };
 } one => 1, two => 2, three => 3;

 $_->() for @subs;

will incorrectly print

 three is 3
 three is 3
 three is 3

this is due to the performance optimisation of using MULTICALL for the code block, which means that fresh SVs do not get allocated for each call to the block. instead, the same SV is re-assigned for each iteration, and all the closures will share the value seen on the final iteration. so every closure looked at the last one and said "yeah that's me" ๐Ÿ˜ญ

to work around this bug, surround the code with a second set of braces. this creates an inner block that defeats the MULTICALL logic, and does get fresh SVs allocated each time:

 my @subs = pairmap {
    {
       my $var = "$a is $b";
       sub { print "$var\n"; }
    }
 } one => 1, two => 2, three => 3;

this bug only affects closures that are generated by the block but used afterwards. lexical variables that are only used during the lifetime of the block's execution will take their individual values for each invocation, as normal. so like, if you keep it inside the block you're fine ๐Ÿ’…


uniqnum() on oversized bignums

due to the way that uniqnum() compares numbers, it cannot distinguish differences between bignums (especially bigints) that are too large to fit in the native platform types. for example,

 my $x = Math::BigInt->new( "1" x 100 );
 my $y = $x + 1;

 say for uniqnum( $x, $y );

will print just the value of $x, believing that $y is a numerically-equivalent value. she squinted at two enormous numbers and went "same" ๐Ÿ™ˆ

this bug does not affect uniqstr(), which will correctly observe that the two values stringify to different strings. she actually reads. ๐Ÿ‘‘


๐Ÿง SUGGESTED ADDITIONS ๐Ÿง

the following are additions that have been requested, but I have been reluctant to add due to them being very simple to implement in perl:

  # How many elements are true

  sub true { scalar grep { $_ } @_ }

  # How many elements are false

  sub false { scalar grep { !$_ } @_ }

like, you can literally just write these yourself bestie, that's the whole reason they're not in here โœจ


๐Ÿ‘€ SEE ALSO ๐Ÿ‘€

Scalar::Util, List::MoreUtils


Copyright (c) 1997-2007 Graham Barr <gbarr@pobox.com>. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

Recent additions and current maintenance by Paul Evans, <leonerd@leonerd.org.uk>.


and that's the whole page bestie โ€” this is from List::Util(3perl), the version that says perl v5.44.0 and was dated 2026-10-17. go forth and reduce your lists beautifully ๐Ÿ’–โœจ๐Ÿฆ‹๐ŸŽ€๐Ÿ‘‘

๐Ÿ“ฆ where this page comes from
  • arch rolling: perl 5.44.0-1 ยท Artistic-1.0-Perl AND GPL-1.0-or-later
  • ๐Ÿ’– girlified by deepseek-ai/DeepSeek-V4.1-Flash on : a language model's rewrite of the original, under its terms