README

Approach

This demo is focused on a SortedLinkedList solution in PHP with a 'Collection' interface to standardize common operations (insert, remove, contains, iteration`). Type safety is enforced with PHPStan at the maximum level, while Rector and Pint ensure consistent code quality and best practices. Testing is performed with Pest and the Pest coverage plugin, achieving full coverage of all functionality.

Installation

composer require chr15k/php-collections

Testing

Run the full test suite:

composer test

Run only unit tests:

composer test:unit

Run type checks (PHPStan):

composer test:types

Run code style checks (Pint):

composer test:lint

Run code refactoring (Rector):

composer test:rector

Apply linting and refactoring (runs both Pint and Rector):

composer tidy

Usage

use Chr15k\Collection\SortedLinkedList;

$list = new SortedLinkedList();
$list->insert(5);
$list->insert(3);
$list->insert(8);
$list->insert(1);

// The list is always sorted
print_r($list->toArray()); // [1, 3, 5, 8]

// Remove a value
$list->remove(3);
print_r($list->toArray()); // [1, 5, 8]

// Check if a value exists
if ($list->contains(5)) {
    echo "5 is in the list!";
}

// Iterate over the list
foreach ($list as $value) {
    echo $value . PHP_EOL;
}

// Get the number of elements
echo $list->count(); // 3

Extending

To create your own collection type, implement the Collection interface and follow the type-safety pattern.

Here is a simple code sample for an ItegerStack:

<?php

use Chr15k\Collection\Contracts\Collection;

class IntegerStack implements Collection
{
    /** @var int[] */
    private array $items = [];

    public function insert(mixed $item): void
    {
        if (!is_int($item)) {
            throw new \InvalidArgumentException("Only integers allowed.");
        }
        array_push($this->items, $item);
    }

    public function remove(mixed $item): void
    {
        $index = array_search($item, $this->items, true);
        if ($index !== false) {
            array_splice($this->items, $index, 1);
        }
    }

    public function contains(mixed $item): bool
    {
        return in_array($item, $this->items, true);
    }

    public function count(): int
    {
        return count($this->items);
    }

    public function toArray(): array
    {
        return $this->items;
    }

    public function getIterator(): \Traversable
    {
        return new \ArrayIterator($this->items);
    }
}

// Usage
$stack = new IntegerStack();
$stack->insert(5);
$stack->insert(10);
$stack->remove(5);

foreach ($stack as $value) {
    echo $value . PHP_EOL;
}

License

MIT