Mojo::Collection - Collection

  1. SYNOPSIS
  2. DESCRIPTION
  3. FUNCTIONS
    1. c
  4. METHODS
    1. TO_JSON
    2. compact
    3. each
    4. first
    5. flatten
    6. grep
    7. head
    8. join
    9. last
    10. map
    11. new
    12. reduce
    13. reverse
    14. shuffle
    15. size
    16. sort
    17. tail
    18. tap
    19. to_array
    20. uniq
    21. with_roles
  5. SEE ALSO

SYNOPSIS

use Mojo::Collection;

# Manipulate collection
my $collection = Mojo::Collection->new(qw(just works));
unshift @$collection, 'it';
say $collection->join("\n");

# Chain methods
$collection->map(sub { ucfirst })->shuffle->each(sub ($word, $num) {
  say "$num: $word";
});

# Use the alternative constructor
use Mojo::Collection qw(c);
c(qw(a b c))->join('/')->url_escape->say;

DESCRIPTION

Mojo::Collection is an array-based container for collections.

# Access array directly to manipulate collection
my $collection = Mojo::Collection->new(1 .. 25);
$collection->[23] += 100;
say for @$collection;

FUNCTIONS

Mojo::Collection implements the following functions, which can be imported individually.

c

my $collection = c(1, 2, 3);

Construct a new array-based Mojo::Collection object.

METHODS

Mojo::Collection implements the following methods.

TO_JSON

my $array = $collection->TO_JSON;

Alias for "to_array".

compact

my $new = $collection->compact;

Create a new collection with all elements that are defined and not an empty string.

# "0, 1, 2, 3"
c(0, 1, undef, 2, '', 3)->compact->join(', ');

each

my @elements = $collection->each;
$collection  = $collection->each(sub {...});

Evaluate callback for each element in collection, or return all elements as a list if none has been provided. The element will be the first argument passed to the callback, and is also available as $_.

# Make a numbered list
$collection->each(sub ($e, $num) {
  say "$num: $e";
});

first

my $first = $collection->first;
my $first = $collection->first(qr/foo/);
my $first = $collection->first(sub {...});
my $first = $collection->first('some_method');
my $first = $collection->first('some_method', @args);

Evaluate regular expression/callback for, or call method on, each element in collection and return the first one that matched the regular expression, or for which the callback/method returned true. The element will be the first argument passed to the callback, and is also available as $_.

# Longer version
my $first = $collection->first(sub { $_->some_method(@args) });

# Find first value that contains the word "mojo"
my $interesting = $collection->first(qr/mojo/i);

# Find first value that is greater than 5
my $greater = $collection->first(sub { $_ > 5 });

flatten

my $new = $collection->flatten;

Flatten nested collections/arrays recursively and create a new collection with all elements.

# "1, 2, 3, 4, 5, 6, 7"
c(1, [2, [3, 4], 5, [6]], 7)->flatten->join(', ');

grep

my $new = $collection->grep(qr/foo/);
my $new = $collection->grep(sub {...});
my $new = $collection->grep('some_method');
my $new = $collection->grep('some_method', @args);

Evaluate regular expression/callback for, or call method on, each element in collection and create a new collection with all elements that matched the regular expression, or for which the callback/method returned true. The element will be the first argument passed to the callback, and is also available as $_.

# Longer version
my $new = $collection->grep(sub { $_->some_method(@args) });

# Find all values that contain the word "mojo"
my $interesting = $collection->grep(qr/mojo/i);

# Find all values that are greater than 5
my $greater = $collection->grep(sub { $_ > 5 });
my $new = $collection->head(4);
my $new = $collection->head(-2);

Create a new collection with up to the specified number of elements from the beginning of the collection. A negative number will count from the end.

# "A B C"
c('A', 'B', 'C', 'D', 'E')->head(3)->join(' ');

# "A B"
c('A', 'B', 'C', 'D', 'E')->head(-3)->join(' ');

join

my $stream = $collection->join;
my $stream = $collection->join("\n");

Turn collection into Mojo::ByteStream.

# Join all values with commas
$collection->join(', ')->say;

last

my $last = $collection->last;

Return the last element in collection.

map

my $new = $collection->map(sub {...});
my $new = $collection->map('some_method');
my $new = $collection->map('some_method', @args);

Evaluate callback for, or call method on, each element in collection and create a new collection from the results. The element will be the first argument passed to the callback, and is also available as $_.

# Longer version
my $new = $collection->map(sub { $_->some_method(@args) });

# Append the word "mojo" to all values
my $mojoified = $collection->map(sub { $_ . 'mojo' });

new

my $collection = Mojo::Collection->new(1, 2, 3);

Construct a new array-based Mojo::Collection object.

reduce

my $result = $collection->reduce(sub {...});
my $result = $collection->reduce(sub {...}, $initial);

Reduce elements in collection with a callback and return its final result, setting $a and $b each time the callback is executed. The first time $a will be set to an optional initial value or the first element in the collection. And from then on $a will be set to the return value of the callback, while $b will always be set to the next element in the collection.

# Calculate the sum of all values
my $sum = $collection->reduce(sub { $a + $b });

# Count how often each value occurs in collection
my $hash = $collection->reduce(sub { $a->{$b}++; $a }, {});

reverse

my $new = $collection->reverse;

Create a new collection with all elements in reverse order.

shuffle

my $new = $collection->shuffle;

Create a new collection with all elements in random order.

size

my $size = $collection->size;

Number of elements in collection.

sort

my $new = $collection->sort;
my $new = $collection->sort(sub {...});

Sort elements based on return value of a callback and create a new collection from the results, setting $a and $b to the elements being compared, each time the callback is executed.

# Sort values case-insensitive
my $case_insensitive = $collection->sort(sub { uc($a) cmp uc($b) });

tail

my $new = $collection->tail(4);
my $new = $collection->tail(-2);

Create a new collection with up to the specified number of elements from the end of the collection. A negative number will count from the beginning.

# "C D E"
c('A', 'B', 'C', 'D', 'E')->tail(3)->join(' ');

# "D E"
c('A', 'B', 'C', 'D', 'E')->tail(-3)->join(' ');

tap

$collection = $collection->tap(sub {...});

Alias for "tap" in Mojo::Base.

to_array

my $array = $collection->to_array;

Turn collection into array reference.

uniq

my $new = $collection->uniq;
my $new = $collection->uniq(sub {...});
my $new = $collection->uniq('some_method');
my $new = $collection->uniq('some_method', @args);

Create a new collection without duplicate elements, using the string representation of either the elements or the return value of the callback/method to decide uniqueness. Note that undef and empty string are treated the same.

# Longer version
my $new = $collection->uniq(sub { $_->some_method(@args) });

# "foo bar baz"
c('foo', 'bar', 'bar', 'baz')->uniq->join(' ');

# "[[1, 2], [2, 1]]"
c([1, 2], [2, 1], [3, 2])->uniq(sub{ $_->[1] })->to_array;

with_roles

my $new_class = Mojo::Collection->with_roles('Mojo::Collection::Role::One');
my $new_class = Mojo::Collection->with_roles('+One', '+Two');
$collection   = $collection->with_roles('+One', '+Two');

Alias for "with_roles" in Mojo::Base.

SEE ALSO

Mojolicious, Mojolicious::Guides, https://mojolicious.org.