<?php
declare(strict_types=1);
/*
* This file is part of Result Type.
*
* (c) Graham Campbell <[email protected]>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace GrahamCampbell\ResultType;
use PhpOption\None;
use PhpOption\Some;
/**
* @template T
* @template E
* @extends \GrahamCampbell\ResultType\Result<T,E>
*/
final class Error extends Result
{
/**
* @var E
*/
private $value;
/**
* Internal constructor for an error value.
*
* @param E $value
*
* @return void
*/
private function __construct($value)
{
$this->value = $value;
}
/**
* Create a new error value.
*
* @template F
*
* @param F $value
*
* @return \GrahamCampbell\ResultType\Result<T,F>
*/
public static function create($value)
{
return new self($value);
}
/**
* Get the success option value.
*
* @return \PhpOption\Option<T>
*/
public function success()
{
return None::create();
}
/**
* Map over the success value.
*
* @template S
*
* @param callable(T):S $f
*
* @return \GrahamCampbell\ResultType\Result<S,E>
*/
public function map(callable $f)
{
return self::create($this->value);
}
/**
* Flat map over the success value.
*
* @template S
* @template F
*
* @param callable(T):\GrahamCampbell\ResultType\Result<S,F> $f
*
* @return \GrahamCampbell\ResultType\Result<S,F>
*/
public function flatMap(callable $f)
{
/** @var \GrahamCampbell\ResultType\Result<S,F> */
return self::create($this->value);
}
/**
* Get the error option value.
*
* @return \PhpOption\Option<E>
*/
public function error()
{
return Some::create($this->value);
}
/**
* Map over the error value.
*
* @template F
*
* @param callable(E):F $f
*
* @return \GrahamCampbell\ResultType\Result<T,F>
*/
public function mapError(callable $f)
{
return self::create($f($this->value));
}
}