How to map generic types?

[Ocramius]

To try out things, I attempted mapping a generic class, where the generic type parameter has not been provided:

<?php

namespace My\App;

use CuyZ\Valinor\Attribute\StaticMethodConstructor;
use CuyZ\Valinor\Mapper\MappingError;
use CuyZ\Valinor\MapperBuilder;

require_once __DIR__ . '/Valinor/vendor/autoload.php';

/** @template T of mixed */
class MyGenericWrapper
{
    /** @var T */
    public mixed $value;
}

$mapper = (new MapperBuilder())
    ->withCacheDir(__DIR__ . '/cache')
    ->mapper();

var_dump($mapper->map(MyGenericWrapper::class, ['value' => 'who knows?']));

This leads to a clear exception:

php example.php 

Fatal error: Uncaught CuyZ\Valinor\Mapper\Exception\InvalidMappingTypeSignature: Could not parse the type `My\App\MyGenericWrapper` that should be mapped: No generic was assigned to the template(s) `T` for the class `My\App\MyGenericWrapper`. in /app/Valinor/src/Mapper/TreeMapperContainer.php:48
Stack trace:
#0 /app/Valinor/src/Mapper/TreeMapperContainer.php(31): CuyZ\Valinor\Mapper\TreeMapperContainer->node('My\\App\\MyGeneri...', Array)
#1 /app/example.php(23): CuyZ\Valinor\Mapper\TreeMapperContainer->map('My\\App\\MyGeneri...', Array)
#2 {main}
  thrown in /app/Valinor/src/Mapper/TreeMapperContainer.php on line 48

The README.md example is clear about generic types where the type parameter has been set:

Valinor/README.md

Lines 258 to 259 in 396f64a

	/** @var SomeCollection<SomeClass> */
	private SomeCollection $classWithGeneric,

How would one request a MyGenericWrapper<int> from the mapper, as a root de-serialization target?

[romm]

Hi @Ocramius, unfortunately type inferring for generics is not handled at all for now, I have to think about it, maybe it could be handled someday.

In the meantime, the following should work:

$mapper->map(MyGenericWrapper::class . '<string>', ['value' => 'who knows?'])

Also, documentation is not finished at all on this topic, but note that you can use the following annotations:

/**
 * @template T of mixed 
 * …or…
 * @template T // mixed is the default type
 *
 * You can also use advanced types:
 * @template T of int|float
 * @template T of SomeClass&SomeOtherClass
 * @template T of string|SomeClass
 * etc…
 */
class MyGenericWrapper
{
    /** @var T */
    public mixed $value;
}

[Ocramius]

Thanks for clarifying!