Sorting it all Out Michael Kaplan's random stuff of dubious value Be sure to read the disclaimer here first!
I am going to take these two questions out of order because (a) locales existed before cultures did, (b) neutral locales set the stage for neutral cultures, and (c) I think it may help us look less lame. Though that third reason is probably just naive optimism on my part....
To see what Windows does with neutral locales, you can look at the documented behavior of ConvertDefaultLocale. Basically, if you pass a neutral like LANG_ENGLISH then it will return the equivalent of MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT) thus 0x009 becomes 0x0409, 0x01a becomes 0x041a, and so forth. Easy, huh?
This ConvertDefaultLocale function calls an internal routine to do its work; the same routine is called by every NLS function, too. Which is a long way around to say that neutral locales do not exist to the Win32 NLS APIs.
Now there is one use for them in Win32 -- resource loading. You can use neutral LCIDs either to more accurately tag resources or to provide an easy fallback mechanism. Of course, if you want to put names on them then you cannot use GetLocaleInfo since asking for the LOCALE_SLANGUAGE of LANG_ENGLISH will give you "English (United States)" which is probably not what you wanted.
(In fact, I wonder what Visual Studio's resource editor does for its strings for these neutrals -- it must have its own strings somewhere, hard coded? Ick!)
In retrospect, it might have been a better idea to not do things that way, but it has shipped this way for at least the last ten versions of Windows. So we are kinda stuck with it.
Anyway, thats neutral locales -- at best, they are tolerated. But you can't really do much with them. Using that ConvertDefaultLocale-ish behavior can actually get you unexpected results sometimes, too. More on this another day.
This brings us to neutral cultures....
In the .NET Framework, a neutral CultureInfo mostly does not do this weird implied LCID fallback thing. There is actual data behind these culures that you can query and use -- and you can get back the actual names and everything. It also does a great job on the resource loading fallback -- using the CultureInfo object's Parent property. The parent property is not based on LCID tricks, either -- it's actual planned data for each culture. Obviously much cooler and a bit more thought out.There is even a CreateSpecificCulture method on a CultureInfo that does the same sort of thing as ConvertDefaultLocale, creating a specific culture from a neutral one.
A lot of you probably noticed where I said "mostly" in that last paragraph (an occupational hazard of having readers who can be as cynical as I am!). Unfortunately, that weird LCID-esque fallback behavior still basically happens for collation and encoding via the culture's CompareInfo and TextInfo objects. Which is not such a big deal, and it is really necessary since both of those objects need the context of a specific culture.
In retrospect, it might have been a better idea to not do things that way -- CompareInfo and TextInfo should not have been made available (as happens for other objects like the associated DateTimeFormatInfo and NumberFormatInfo), but it has shipped this way for two versions so we are kinda stuck with it.
One important difference that distinguishes them from neutral locales is that one could create a class that is derived from CultureInfo that contains language-specific information which would make more sense in neutral cultures, which is really a fancy way of saying "language-only cultures" (which is itself kind of a fancy way of say something).
There are also some odd situations with the LCID property of the CultureInfo, but thats a separate issue. More on this another day, too.
So, thats neutral cultures. Mostly not useful, except for resources -- except in the same way that they are useful in Win32 (by pretending its a specific culture). Or for potential extensibility either by Microsoft or by developers in the future.
Three steps forward, one step back? :-)
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