Psalm - a static analysis tool for PHP

<?php

declare(strict_types=1);

use Countable;
use IteratorAggregate;

/**
 * @template K of array-key
 * @template V
 * @extends IteratorAggregate<K, V>
 */
interface Collection extends Countable, IteratorAggregate
{
	/** @return static<int<0, max>, K> */
	public function getKeys(): static;

/**
	 * @param callable(V $value, K $key): bool $predicate
	 * @return static<K, V>
	 */
	public function find(callable $predicate): static;

/**
	 * @template OV
	 * @param callable(V $value, K $key): OV $mapper
	 * @return static<K, OV>
	 */
	public function map(callable $mapper): static;

/**
	 * @template OV
	 * @param callable(V $value, K $key): iterable<OV> $mapper
	 * @return static<int<0, max>, OV>
	 */
	public function flatMap(callable $mapper): static;

/**
	 * @template OK of array-key
	 * @param callable(V $value, K $key): OK $groupMapper
	 * @return static<OK, static<K, V>>
	 */
	public function groupBy(callable $groupMapper): static;

/**
	 * @param int<1, max> $size
	 * @return static<int<0, max>, static<K, V>>
	 */
	public function chunk(int $size): static;
}

Snippet created on January 27 2025 at 11:28 UTC