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Typhoon Type

Typhoon Type is an object abstraction over the modern PHP type system. Use this library to build tools that work with sophisticated types.

Here are some examples of potential use-cases:

use Typhoon\Type\types;

$data = (new MyAwesomeJsonDecoder())->decode(
    json: '[1, 0.5, "213"]',
    type: types::list(types::numeric),
);

var_dump($data);
array(3) {
  [0] => int(1)
  [1] => float(0.5)
  [2] => string(3) "213"
}

Or:

use Typhoon\Type\types;

final readonly class GetUserResponse
{
    /**
     * @param non-empty-string $name
     * @param 'user'|'admin' $group
     */
    public function __construct(
        public Uuid $id,
        public string $name,
        public string $group,
    ) {}
}

echo (new MyAwesomeOpenApiGenerator())->generateSchema(types::object(GetUserResponse::class));
GetUserResponse:
  type: object
  properties:
    id:
      type: string
      format: uuid
      example: b609e6a9-bba6-4599-9faa-cc9977353bb4
    name:
      type: string
      example: Hello world!
    group:
      type: string
      enum: [ user, admin ]

Installation

composer require typhoon/type

Constructing types

Typhoon types can be constructed via the Typhoon\Type\types static factory. Let's express this monstrous type via the Typhoon DSL:

array{
    a: non-empty-string,
    b?: int|float,
    c: Traversable<numeric-string, false>,
    d: callable(PDO::*, TSend#Generator=, scalar...): void,
    ...
}
use Typhoon\Type\types;

$type = types::unsealedArrayShape([
    'a' => types::nonEmptyString,
    'b' => types::optional(types::union(types::int, types::float)),
    'c' => types::object(Traversable::class, [types::numericString, types::false]),
    'd' => types::callable(
        parameters: [
            types::classConstantMask(PDO::class),
            types::param(types::classTemplate(Generator::class, 'TSend'), hasDefault: true),
            types::param(types::scalar, variadic: true),
        ],
        return: types::void,
    ),
]);

As you can see, creating types in Typhoon is a lot of fun, especially if you work in IDE with autocompletion 😉

Design

Unlike other solutions, Typhoon Type does not expose concrete type classes in its API. Instead, it provides only a common Type interface, a type factory types, and a TypeVisitor with destructurization. This approach gives several advantages:

  1. The visitor has only a minimal subset of type methods that must be implemented when describing a type algebra. Complexity of the other types is hidden and can be completely ignored.
  2. Memory efficient enums can be used for all atomic types and for aliases of commonly used compound types.
  3. Using of downcasting via the instanceof operator is automatically discouraged, since all Type implementations are @internal ( see PHPStan: Why Is instanceof *Type Wrong and Getting Deprecated?).

Printing types

To cast any type to string, use the Typhoon\Type\stringify() function:

use Typhoon\Type\types;
use function Typhoon\Type\stringify;

var_dump(
   stringify(
       types::Generator(
           key: types::nonNegativeInt,
           value: types::classTemplate(Foo::class, 'T'),
           send: types::scalar,
       ),
   ),
); // Generator<int<0, max>, T#Foo, scalar, mixed>

Comparing types

Typhoon team is currently working on a type comparator. Until it is released, you can use DefaultTypeVisitor for simple checks:

use Typhoon\Type\Type;
use Typhoon\Type\types;
use Typhoon\Type\Visitor\DefaultTypeVisitor;

/**
 * @extends DefaultTypeVisitor<bool>
 */
final class BasicIntChecker extends DefaultTypeVisitor
{
    public function int(Type $type, Type $minType, Type $maxType): mixed
    {
        return true;
    }

    public function intValue(Type $type, int $value): mixed
    {
        return true;
    }

    public function intMask(Type $type, Type $ofType): bool
    {
        return true;
    }

    protected function default(Type $type): bool
    {
        return false;
    }
}

var_dump(types::positiveInt->accept(new BasicIntChecker())); // true
var_dump(types::callableString()->accept(new BasicIntChecker())); // false

Compatibility with Psalm and PHPStan

Native PHP types

PHPStan Psalm Typhoon
null null types::null, types::value(null)
void void types::void
never never types::never
true true types::true, types::value(true)
false false types::false, types::value(false)
bool, boolean bool types::bool
int, integer int types::int
float, double float types::float
string string types::string
resource resource types::resource
array array types::array
iterable iterable types::iterable
object object types::object
Foo Foo types::object(Foo::class)
Closure Closure types::Closure (an alias for types::object(Closure::class))
Generator Generator types::Generator() (an alias for types::object(Generator::class))
self self types::self()
parent parent types::parent()
static static types::static()
callable callable types::callable
?string ?string types::nullable(types::string)
int|string int|string types::union(types::int, types::string)
Countable&Traversable Countable&Traversable types::intersection(types::object(Countable::class), types::object(Traversable::class))
mixed mixed types::mixed

Numbers

PHPStan Psalm Typhoon
literal-int literal-int types::literalInt
123 123 types::int(123), types::value(123)
positive-int positive-int types::positiveInt
negative-int negative-int types::negativeInt
non-positive-int non-positive-int types::nonPositiveInt
non-negative-int non-negative-int types::nonNegativeInt
non-zero-int negative-int|positive-int types::nonZeroInt
int<-5, 6> int<-5, 6> types::intRange(-5, 6)
int<min, 6> int<min, 6> types::intRange(max: 6)
int<-5, max> int<-5, max> types::intRange(min: -5)
int-mask<1, 2, 4> int-mask<1, 2, 4> types::intMask(1, 2, 4)
int-mask-of<Foo::INT_*> int-mask-of<Foo::INT_*> types::intMaskOf(types::classConstantMask(Foo::class, 'INT_')
types::literalFloat
types::floatRange(-0.001, 2.344)
12.5 12.5 types::float(12.5), types::value(12.5)
numeric numeric types::numeric

Strings

PHPStan Psalm Typhoon
non-empty-string non-empty-string types::nonEmptyString
literal-string literal-string types::literalString
'abc' 'abc' types::string('abc'), types::value('abc')
truthy-string, non-falsy-string truthy-string, non-falsy-string types::truthyString, types::nonFalsyString
numeric-string numeric-string types::numericString
callable-string callable-string types::callableString()
class-string<Foo> class-string<Foo> types::classString(types::object(Foo::class))
Foo::class Foo::class types::class(Foo::class)
class-string class-string types::classString
interface-string
trait-string
enum-string
lowercase-string

Constants

PHPStan Psalm Typhoon
PHP_INT_MAX PHP_INT_MAX types::constant('PHP_INT_MAX')
Foo::BAR Foo::BAR types::classConstant(Foo::class, 'BAR')
Foo::IS_* Foo::IS_* types::classConstant(Foo::class, 'IS_*'), types::classConstantMask(Foo::class, 'IS_')

Arrays and iterables

PHPStan Psalm Typhoon
array-key array-key types::arrayKey
Foo[] Foo[] types::array(value: types::object(Foo::class))
list<string> list<string> types::list(types::string)
non-empty-list<string> non-empty-list<string> types::nonEmptyList(types::string)
list{int, string} list{int, string} types::listShape([types::int, types::string])
list{int, 1?: string} list{int, 1?: string} types::listShape([types::int, types::optional(types::string)])
list{int, ...} list{int, ...} types::unsealedListShape([types::int])
❌ (issue) list{int, ...<string>} types::unsealedListShape([types::int], types::string)
array<string> array<string> types::array(value: types::string)
array<int, string> array<int, string> types::array(types::int, types::string)
non-empty-array<array-key, string> non-empty-array<array-key, string> types::nonEmptyArray(types::arrayKey, types::string)
array{} array{} types::array()
array{int, string} array{int, string} types::arrayShape([types::int, types::string])
array{int, a?: string} array{int, a?: string} types::arrayShape([types::int, 'a' => types::optional(types::string)])
array{int, ...} array{int, ...} types::unsealedArrayShape([types::int])
❌ (issue) array{float, ...<int, string>} types::unsealedArrayShape([types::float], types::int, types::string)
key-of<Foo::ARRAY> key-of<Foo::ARRAY> types::keyOf(types::classConstant(Foo::class, 'ARRAY'))
value-of<Foo::ARRAY> value-of<Foo::ARRAY> types::valueOf(types::classConstant(Foo::class, 'ARRAY'))
TArray[TKey] TArray[TKey] types::offset($arrayType, $keyType)
iterable<object, string> iterable<object, string> types::iterable(types::object, types::string)
iterable<string> iterable<string> types::iterable(value: types::string)
Generator<TKey, TValue, TSend, TReturn> Generator<TKey, TValue, TSend, TReturn> types::object(Generator::class, [$key, $value, $send, $return]), types::Generator($key, $value, $send, $return)
callable&array callable-array types::callableArray()

Objects

PHPStan Psalm Typhoon
Foo<string, float> Foo<string, float> types::object(Foo::class, [types::string, types::float])
self<string, float> self<string, float> types::self([types::string, types::float])
parent<string, float> parent<string, float> types::parent([types::string, types::float])
static<string, float> static<string, float> types::static([types::string, types::float])
object{prop: string} object{prop: string} types::object(['prop' => types::string])
object{prop?: string} object{prop?: string} types::object(['prop' => types::optional(types::string)])

Callables

PHPStan Psalm Typhoon
callable-string callable-string types::callableString()
callable&array callable-array types::callableArray()
callable(string): void callable(string): void types::callable([types::string], types::void)
callable(string=): mixed callable(string=): mixed types::callable([types::param(types::string, hasDefault: true)])
callable(...string): mixed callable(...string): mixed types::callable([types::param(types::string, variadic: true)])
callable(&string): mixed callable(&string): mixed types::callable([types::param(types::string, byReference: true)])
Closure(string): void Closure(string): void types::Closure([types::string], types::void)
Closure(string=): mixed Closure(string=): mixed types::Closure([types::param(types::string, hasDefault: true)])
Closure(...string): mixed Closure(...string): mixed types::Closure([types::param(types::string, variadic: true)])
Closure(&string): mixed Closure(&string): mixed types::Closure([types::param(types::string, byReference: true)])
pure-callable pure-callable

Other

PHPStan Psalm Typhoon
scalar scalar types::scalar
Template T Template T types::functionTemplate('foo', 'T'), types::classTemplate(Foo::class, 'T'), types::methodTemplate(Foo::class, 'bar', 'T')
Alias X Alias X types::classAlias(Foo::class, 'X')
(T is string ? true : false) (T is string ? true : false) types::conditional($type, types::string, types::true, types::false)
($return is true ? string : void) ($return is true ? string : void) types::conditional(types::functionArg('var_export', 'return'), types::true, types::string, types::void)
!null (only in assertions) !null (only in assertions) types::not(types::null)
properties-of<T>
class-string-map<T of Foo, T>
open-resource open-resource
closed-resource closed-resource