krlove/collections

Strictly typed data structures for PHP

1.0.0 2022-08-14 20:53 UTC

This package is auto-updated.

Last update: 2022-11-20 09:52:05 UTC


README

Strictly typed data structures for PHP.

Installation

composer require krlove/collections

Sequence

Sequence is an ordered collection of variables of any type.

$sequence = Sequence::of('string');
$sequence->push('Gandalf');
$sequence->push('Bilbo');
$sequence->push('Frodo');
$sequence->remove(1);

foreach ($sequence as $index => $value) {
    echo $index . ': ' . $value . PHP_EOL;
}
0: Gandalf
1: Frodo

Map

Map contains key-value pairs, where each key is unique.

$map = Map::of('string', 'array');
$map->set('fruits', ['apple', 'banana', 'pear']);
$map->set('vegetables', ['tomato', 'potato', 'onion']);
$map->set('berries', ['strawberry', 'blueberry', 'raspberry']);
$map->remove('vegetables');
$map->set('berries', ['bilberry']);

foreach ($map as $key => $value) {
    echo $key . ': ' . var_export($value, true) . PHP_EOL;
}
fruits: array (
  0 => 'apple',
  1 => 'banana',
  2 => 'pear',
)
berries: array (
  0 => 'bilberry',
)

Set

Set is a collection of unique variables of any type.

$set = Set::of('string');
$set->add('Gandalf');
$set->add('Bilbo');
$set->add('Bilbo');

echo var_export($set->toArray(), true) . PHP_EOL;
array (
  0 => 'Gandalf',
  1 => 'Bilbo',
)

Types

All collections are strictly typed.

$sequence = Sequence::of('int');
$sequence->push('Gandalf');
PHP Fatal error:  Uncaught Krlove\Collection\Exception\TypeException: Variable must be of type int, string given

Supported types are:

  • null
  • bool
  • int
  • float
  • string
  • array
  • iterable
  • callable
  • resource
  • object
  • class (objects of specific class or interface)
  • mixed (any type is allowed)

Nullable

Types can be nullable.

$sequence = Sequence::of('?string');
$sequence->push(null);

Freezable

After collection is "frozen", it becomes read-only, no changes are allowed to it. It is impossible to "unfreeze" the collection once it is frozen, but it is possible to copy it.

$sequence = Sequence::of('string');
$sequence->push('Gandalf');
$sequence->freeze();
//$sequence->push('Bilbo'); Fatal error: Uncaught Krlove\Collection\Exception\FrozenException: Sequence is frozen and can not be changed
$copy = $sequence->copy();
$copy->push('Bilbo');

foreach ($copy as $index => $value) {
    echo $index . ': ' . $value . PHP_EOL;
} 
0: Gandalf
1: Bilbo

Usage

PHP does not support generic types, so it is impossible to define a property as follows.

private Map<int, string> $map; // invalid

Some additional code must be written to ensure collections of proper types are used

class MyClass
{
    /**
     * @var Map<int, string> 
     */
    private Map $map;
    
    public function __construct()
    {
        $this->map = Map::of('int', 'string');
    }
    
    /**
     * @param Map<int, string> $map
     * @return void
     */
    public function setMap(Map $map): void
    {
        if (!$map->isOf('int', 'string')) {
            // throw exception
        }
        
        $this->map = $map;
    }
}