The binding schemes that makes use of the autoloader does not correctly handle optionality as they need to know if something will be loaded or not.
This could either be implemented by:
- querying the autoloader if it will be able to load something (without actually loading),
- performing early loading, stashing the result until it is being used (it may be excluded later so this is wasteful.
- make the optionality carry through to the resolution phase (now optionality is checked when URIs are expanded and the effective set of included - excluded is processed.