Interfaces, classes and factories for photographic densities, exposure values, and zone numbers.
// PHP 7.1+
$ composer require filmtools/commons:^2.0
// PHP 7.0
$ composer require filmtools/commons:^1.0
$ git clone https://github.com/filmtools/commons.git
$ composer install
# either, or, and:
$ composer test
$ vendor/bin/phpunit