• Collection for configuration items
• Deferred item definition, item is never defined until it is used
• Self-descriptive, with IDE auto-completion powered
• Deferred resolution of current and default value
• Enumeration and export for administrative script and manager
• Full control for populating pre-loaded data
• Caching via PHP's ultra-fast APCu with write-back on demand
• Shipped with some helpers for quick reader and writer

Extend Collection with each definition a public function

An Live Template of PHPStorm like this can be added to make a shortcut

public function $CONF_NAME$(): Item
{
    return $this->make(__FUNCTION__, $DEF_VALUE$, $READER$, $WRITER$);
}

Instantiate your own Loader with a callback that return the array of raw data of configuration. The key shall be the Collection's FQN. Just require the dumped file in case of using a saved php configuration file. Call setApcu('key_prefix') to enable APCu caching.

Instantiate needed children instance of Collection, which a DI container is suggested to fulfil the task. Pass the loader in previous step. Then you call get the configuration by $collection->item()(). Note that __invoke() is used. Otherwise what you get is a Item object having many useful methods like def() and raw().

See tests for more detailed usage.