I am attempting to write a Locale-aware framework. Some classes will have a list of known Locales (being the Locales for which they have specific data).

When the user chooses a Locale, the class may not have specific data for exactly that Locale. In that case it chooses the closest available Locale.


I want to reproduce the behaviour of the ClassLoader. If I ask for a en_IE Locale, but the class knows about en, en_UK and en_US Locales, I want to get the en Locale.

Is there a standard library / technique to do this sort of comparison?