Dgame / php-optional

src/Optional.php

<?php

namespace Dgame\Optional;

/**
 * Interface Optional
 * @package Dgame\Optional
 */
interface Optional
{
    /**
     * @param mixed $value
     *
     * @return bool
     */
    public function isSome(&$value = null): bool;

    /**
     * @return bool
     */
    public function isNone(): bool;

    /**
     * @return mixed
     */
    public function unwrap();

    /**
     * @param $value
     *
     * @return mixed
     */
    public function default($value);

    /**
     * @param callable $callback
     *
     * @return Optional
     */
    public function ensure(callable $callback): self;

    /**
     * @return Optional
     */
    public function ensureNotFalse(): self;

    /**
     * @param $value
     *
     * @return bool
     */
    public function isEqualTo($value): bool;

    /**
     * @param $value
     *
     * @return bool
     */
    public function isNotEqualTo($value): bool;

    /**
     * @param $value
     *
     * @return bool
     */
    public function isIdenticalTo($value): bool;

    /**
     * @param $value
     *
     * @return bool
     */
    public function isNotIdenticalTo($value): bool;

    /**
     * @param callable $callback
     */
    public function do(callable $callback);

For interfaces and abstract methods it is generally a good practice to add a @return annotation even if it is just @return void or @return null, so that implementors know what to do in the overridden method.

}