Re: How to use Unicode::Collate in multilinguage apps?

On Mon, 29 Mar 2004 23:44:00 +0100
Rich <[email protected]> wrote:

> I now realise that some per-language tailoring would be needed for sensible
> results. Unicode::Collate::Locale seems like the kind of think I was
> looking for, and any tailoring is better than none :)
> 
> Using the multi-lingual server scenario I was initially discussing, would
> one of the following usages be correct (yes, it's just pseudocode and
> exists in a world where no errors ever occur!):

Though I have not worked with any multitasking application,
I suppose a possible snag is the size of DUCET (the file named
allkeys.txt) which should cause slowness of construction of
a collator and large memory use for storage.

> 1)
> 
>  my %collators;
> 
>  for ( $server_loop )
>  {
>    my $lang_tag = Server->requested_lang_tag;
> 
>    my $collator   = $collators{$lang_tag} 
>                 ||= Unicode::Collate::Locale->new(locale => $lang_tag);
> 
>    ...
>  }

1) creates a new collator if $lang_tag value is new.
Say when the old one was 'en' (English) and the new one was 'it' (Italian),
Unicode::Collate::Locale->new will return a default collator each time.
I.e. $collators{en} and $collators{it} work as same but memory is not shared.

When Unicode::Collate->new is called, all the data generated by parsing
of a table file are stored in a collator which is a blessed hash.
The reason why so is, as I thinked, if (a part of) data newly created
are stored in other places, say, in a cache at the package namespace
(e.g. something like %Unicode::Collate::Cache), it might cause some problem
on handling memory in the cache by users outside the package.

I think parhaps it should be necessary that a user can determine
whether two (or more) $lang_tag values create the same collator or not.

    my $lang_tag = Server->requested_lang_tag;
    my $canonical = Unicode::Collate::Locale::canonical_name($lang_tag);

    # if $canonical is same as an old one, the collator for it should be
    # same. After seeing if $canonical is new, a collator can be created.
    # The function name leaves room for reconsideration.

Now Unicode::Collate::Locale::_locale() does the same thing
as canonical_name(), but that function is internal and not public.

Regards,
SADAHIRO Tomoyuki