Should locale parameter accept an optional array?

[davidbarratt]

Sometimes the user provides (via the Accept-Language header) a list of languages that they know:

Accept-Language: en-US;q=0.8,es;q=0.5,ja;q=0.3

since the user is providing a list of languages, it might be helpful to accept that list as fallbacks.

For instance, based on that header, I would generate this list:

en-US
es
ja

and I would expect it to fallback like this:

en-US
en
es
ja

Perhaps the locale could accept a string or an array of strings? What do you think?