Tuple and Expanded

TupleType

class TupleType implements Type
{
    /**
     * @param list<Type> $types
     */
    public function __construct(
        public array $types,
    ) {}
}

Represents an array of types: array{ string, int }

ExpandedType

class ExpandedType implements Type
{
    public function __construct(
        public readonly Type $innerType
    ) {}
}

Represents an expanded tuple type. Let’s take callable and \Closure as an example:

/**
 * @template TReturn
 * @template ...TParameter
 */
interface callable {}

/**
 * @template TReturn
 * @template ...TParameter
 *
 * @implements callable<TReturn, ...TParameter>
 */
class Closure implements callable {}

The above is more or less how callable and \Closure works in this library. Instead of having a separate type for callable and it’s subtypes, we chose to go another route: variadic type parameters. In this case, the TParameter is variadic - meaning it accepts unlimited amount of parameters, the same way variadic function parameter does. So callable(string, int, float): bool maps to callable<bool, string, int, float>, even though there are only two type parameters - TReturn and TParameter.

Note

@template ...T isn’t a valid PHPDoc syntax - it’s just for demonstration purposes :)

So what is ExpandedType? Well, that’s exactly what ...TParameter is in @implements callable<TReturn, ...TParameter> - it expands the variadic TParameter type, the same as you would when calling a function: func(...$args)