On Wednesday, May 4, 2011 at 7:53 PM, Phillips, Addison wrote:
> Hi Marcos and Webapps,
>
> This is a personal last call comment [chair hat off]. I realize that it is
> late, but I was on vacation....
>
> A developer recently sent me a code review implementing the latest spec and I
> found some code that was utterly mystifying to me. It turns out that he
> implemented rule 9.1.12 in the current spec, which defines
> "user_agent_locales". This text seems really odd to me.
>
> What I expected was from looking at step 8 in section 9.1.17 was to have a
> "language priority list" containing the locale(s) to search for using the
> Lookup algorithm from BCP 47. I expected that this list would usually consist
> of a single locale identifier (language tag) representing the current Widget
> runtime locale, although an implementation might occasionally use
> Accept-Language or some other source for a full language priority list such
> as shown in the examples. I read "user_agent_locales" to be the Widget's
> version of a language priority list.
>
> The odd thing is that the rules in 9.1.12 "explode" each language range, but
> the BCP 47 Lookup algorithm already does this. For example, 9.1.12 would
> convert the language priority list "zh-Hans-CN,*" to the user_agent_locales
> string "zh-Hans-CN,zh-Hans,zh,*". But this is unnecessary because the Lookup
> algorithm's "remove from right logic" already does this (or, for xml:lang
> matching, you can use prefix matching). If you do both the lookup algorithm
> *and* the computation of user_agent_locales, you will do a bunch of
> unnecessary searching with lower efficiency.
>
> If what you want is to define lookup by computing user_agent_locales and then
> doing exact path matches for each element, then that's okay, I suppose,
> although personally I would (and have) implemented it in memory rather than
> by computing an "exploded" user_agent_locales list.
>
> So my request/proposal would be to either (a) eliminate section 9.1.12 and
> just specify BCP 47 Lookup or (b) specify the complete match algorithm using
> the list computed in 9.1.12 and state that it is compatible with BCP 47
> lookup. I would strongly prefer (a) personally. The internationalization work
> in ECMAScript and at least one implementation do it that way.
I am all for using (a), so long as the result is the same as what we currently
have today (i.e., we don't break existing implementations and the test suite).
