The `Source` class is a new entry point for sources that are not plain
array or iterable. It allows accessing other features like camel-case
keys or custom paths mapping in a convenient way.
It should be used as follows:
```php
$source = \CuyZ\Valinor\Mapper\Source\Source::json($jsonString)
->camelCaseKeys()
->map([
'towns' => 'cities',
'towns.*.label' => 'name',
]);
$result = (new \CuyZ\Valinor\MapperBuilder())
->mapper()
->map(SomeClass::class, $source);
```
This modifier can be used to change paths in the source data using a dot
notation.
The mapping is done using an associative array of path mappings. This
array must have the source path as key and the target path as value.
The source path uses the dot notation (eg `A.B.C`) and can contain one
`*` for array paths (eg `A.B.*.C`).
```php
final class Country
{
/** @var City[] */
public readonly array $cities;
}
final class City
{
public readonly string $name;
}
$source = new \CuyZ\Valinor\Mapper\Source\Modifier\PathMapping([
'towns' => [
['label' => 'Ankh Morpork'],
['label' => 'Minas Tirith'],
],
], [
'towns' => 'cities',
'towns.*.label' => 'name',
]);
// After modification this is what the source will look like:
[
'cities' => [
['name' => 'Ankh Morpork'],
['name' => 'Minas Tirith'],
],
];
(new \CuyZ\Valinor\MapperBuilder())
->mapper()
->map(Country::class, $source);
```
