A Collection Type

Requirements

php >= 7.1

Installation

$ composer require lucid/collection

Collections

Creating typed collections

<?php

namespace Acme\Data;

use Lucid\Collection\AbstractCollection;

class Integers extends AbstractCollection
{
    private $ints;
    
    public function __construct(int ...$integers)
    {
        $this->ints = $integers;
    }
    
    public function reduce(callable $reduce) : int
    {
        return parent::reduce($reduce);
    }

    protected function getData() : array
    {
        return $this->ints;
    }
}

Collection methods

map : Lucid\Collection\CollectionInterface

Returns a new Collection containing the mapped values of the origin collection.

<?php

$ints = new Integers(1, 2, 3, 4, 5, 6);


$res = $ints->map(function(int $num) {
    return $num * $num;
})->toArray();

// => [1, 4, 9, 16, 25, 36] 

filter : Lucid\Collection\CollectionInterface

Returns a new Collection containing the filtered values of the origin collection. CollectionInterface:filter() also takes an optional second argument int $flag which can be either CollectionInterface::FILTER_USE_KEY to filter by value keys, or CollectionInterface::FILTER_USE_BOTH, to filter by key and value.

<?php

$ints = new Integers(1, 2, 3, 4, 5, 6);


$res = $ints->filter(function(int $num) {
    return $num > 3;
})->toArray();

// => [4, 5, 6] 

slice : Lucid\Collection\CollectionInterface

Returns a new Collection containing a slice of the original collection.

<?php

$ints = new Integers(1, 2, 3, 4, 5, 6);


$res = $ints->slice(2)->toArray();
// => [2, 4, 5, 6] 

$res = $ints->slice(2, 2)->toArray();
// => [2, 4]

$res = $ints->slice(-1)->toArray();
// => [6]

head : Lucid\Collection\CollectionInterface

Returns a new Collection containing the top portion of the original collection. CollectionInterface::head() also takes an optional argument int $max.

<?php

$ints = new Integers(1, 2, 3, 4, 5, 6);


$res = $ints->head()->toArray();
// => [1] 

$res = $ints->head(3)->toArray();
// => [1, 2, 3] 

tail : Lucid\Collection\CollectionInterface

Returns a new Collection containing the tail portion of the original collection. CollectionInterface::tail() also takes an optional argument int $max.

<?php

$ints = new Integers(1, 2, 3, 4, 5, 6);


$res = $ints->tail()->toArray();
// => [2, 3, 4, 5, 6] 

$res = $ints->tail(3)->toArray();
// => [4, 5, 6] 

each : Lucid\Collection\CollectionInterface

<?php

$ints = new Integers(1, 2, 3, 4, 5, 6);

$ints->each(function (int $int) {
    echo $int;
});

// you can also do
foreach ($ints as $int) {
    echo $int;
}