Shared constructor

[Nemoden]

"Share" is a nice option of Dice that guarantees not to create an object, but reuse already created one. But I encounter a lot of situations when I want to get the same object only if constructor parameters are the same. Consider common task like:

$dataFinder = $dice->create("DataFinder", [$model, $id]);
$dataFinder->getData();

Suppose DataFinder can cache result for searching a record id $id for a model $model.
If we use "shared" rule of Dice, we will always get same instance of DataFinder despite that we might want to get an instance of DataFinder for the particular $model and $id.

This pull request adds sharedConstructor rule so you can tell Dice not to create an object if an object of this type was already created with this particular constructor params.

In my practice this patterns occurs so many times... I usually do a caching proxy which is okay but it would be nice if we had such a feature in Dice right out of the box.

[Nemoden]

P.S. I am sorry for commit names, I've pushed first commit and than added extra tests and messed with the commit message trying to amend previos commit, but made a new one with the same msg :(

[Nemoden]

P.P.S. I am also not sure about the name of the feature "sharedConstructor" seems a little misguiding.

[TRPB]

There so few cases where you should be calling create directly (ideally in just one place) that the usefulness of this should be incredibly limited. If you find yourself calling $dice->create in multiple places I'd suggest it's more likely a SRP issue.

Is there a reason that named parameters cannot be used here?

$dataFinderA = [
    'instanceOf' = 'DataFinder',
    'constructParams' => [$model, 'a']
];

$dataFinderB = [
    'instanceOf' = 'DataFinder',
    'constructParams' => [$model, 'b']
];

$dice->addRule('DataFinderA', $dataFinderA);
$dice->addRule('DataFinderB', $dataFinderB);

$dfA = $dice->create('DataFinderA');

It's  also incredibly easy to automate this. Wherever you currently have `$dice->create` replace it with:

```php
if ($dice->getRule('DataFinder' . $id) != $dice->getRule('*') {
    $dice->addRule('DataFinder' . $id, [
        'instanceOf' => 'DataFinder',
        'constructParams' => [$model, $id]
       'shared' => true
    ]);
}

$dataFinder = $dice->create('DataFinder' . $id);

I think if this is really needed, a better and much simpler solution is wildcard names. You'd assign the rule as normal:

$dataFinder = [
    'shared' => true
]

$dice->addRule('DataFinder, $dataFinder);

But when creating the object, provide a unique ID, perhaps something like:

$dice->create('DataFinder:' . $id, [$model, $id]);

Which, when $id is 123 would use the instance name DataFinder:123 but create an instance of DataFinder.