<?php declare(strict_types=1);
/*
* This file is part of sebastian/type.
*
* (c) Sebastian Bergmann <[email protected]>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace SebastianBergmann\Type;
use function array_unique;
use function assert;
use function count;
use function implode;
use function sort;
final class IntersectionType extends Type
{
/**
* @psalm-var non-empty-list<Type>
*/
private $types;
/**
* @throws RuntimeException
*/
public function __construct(Type ...$types)
{
$this->ensureMinimumOfTwoTypes(...$types);
$this->ensureOnlyValidTypes(...$types);
$this->ensureNoDuplicateTypes(...$types);
$this->types = $types;
}
public function isAssignable(Type $other): bool
{
return $other->isObject();
}
public function asString(): string
{
return $this->name();
}
public function name(): string
{
$types = [];
foreach ($this->types as $type) {
$types[] = $type->name();
}
sort($types);
return implode('&', $types);
}
public function allowsNull(): bool
{
return false;
}
/**
* @psalm-assert-if-true IntersectionType $this
*/
public function isIntersection(): bool
{
return true;
}
/**
* @psalm-return non-empty-list<Type>
*/
public function types(): array
{
return $this->types;
}
/**
* @throws RuntimeException
*/
private function ensureMinimumOfTwoTypes(Type ...$types): void
{
if (count($types) < 2) {
throw new RuntimeException(
'An intersection type must be composed of at least two types'
);
}
}
/**
* @throws RuntimeException
*/
private function ensureOnlyValidTypes(Type ...$types): void
{
foreach ($types as $type) {
if (!$type->isObject()) {
throw new RuntimeException(
'An intersection type can only be composed of interfaces and classes'
);
}
}
}
/**
* @throws RuntimeException
*/
private function ensureNoDuplicateTypes(Type ...$types): void
{
$names = [];
foreach ($types as $type) {
assert($type instanceof ObjectType);
$names[] = $type->className()->qualifiedName();
}
if (count(array_unique($names)) < count($names)) {
throw new RuntimeException(
'An intersection type must not contain duplicate types'
);
}
}
}