Singleton class for SSN

[soullivaneuh]

The SSN validator is special. We have to instantiate it before use it for validation.

I think is for avoid code generation (generate('CA')) on each validation?

In this case, could we think about use it as a singleton class?

See here (FR): http://fr.wikipedia.org/wiki/Singleton_%28patron_de_conception%29#PHP_5

I suggest it because with this code design, I will have to instantiate it on each validation with my Symfony Validator wrapping.

Could work on it. This should be on a next major release.

[ronanguilloux]

Please send a PR

[soullivaneuh]

Will work on it.

Just to show you the problem:

• All constraint call your validators like this: https://github.com/Soullivaneuh/IsoCodesValidator/blob/597486d1eb96717ffd3408d3ed7864e07e6476fd/src/Constraints/VatValidator.php#L23
• En for SSN: https://github.com/Soullivaneuh/IsoCodesValidator/blob/597486d1eb96717ffd3408d3ed7864e07e6476fd/src/Constraints/SsnValidator.php#L24-L26

As you can see, I have to instantiate this class for each validation.

[soullivaneuh]

The generate method of Ssn is never called from class validation.

What is the goal of this method?

[ronanguilloux]

To generate a SSN, based on state.

[soullivaneuh]

But it is not used for validation, is it?

If not, are you OK to make it static too?

[soullivaneuh]

Closed for #34.