[loc-en-dev] Equality of base locale and LocaleServiceProvider implementation

[Yoshito Umaoka]

Naoto Sato wrote:
> Umaoka-san,
>
> I don't think this is a compatibility issue, because the existing SPI 
> implementations should still work compatible with the locales without 
> extensions.  Possible issue would only arise with the new locales.
>
> BTW, current SPI implementation invocation already involves fallback 
> itself. i.e., say the request locale is xx_YY_foo_bar, and one SPI 
> provider implements xx_YY, then that provider's service is used.  So 
> adding the extension fallback is not that ugly to me. 
Yes, I know the current fallback strategy.
LDML extensions are designed for specifying optional behavior for a 
locale.  Therefore, as we described in the very first proposal, 
extensions are carried in each level.  More specifically, if a locale 
xx-yy-zzzz-u-cu-usd is requested, below is the candidate list.

xx-yy-zzzz-u-usd
xx-yy-u-usd
xx-u-usd

If we need "extensionless" version inserted, it becomes

xx-yy-zzzz-u-usd
xx-yy-zzzz
xx-yy-u-usd
xx-yy
xx-u-usd
xx

Don't you think it's somewhat ugly?

-Yoshito