The LanguageTag module helps perform many different common operations regarding language identification, filtering, etc. It currently integrates the following standards: BCP47 (tags), RFC4647 (filtering), and, via UTS35, RFC6497 (extension 't') and RFC6067.

Basic Usage

use Intl::LanguageTag;
    my $tag = LanguageTag.new("oc-Latn-ES-aranes-t-en-UK");

say $tag.language.code;   #  ↪︎ "oc"
    say $tag.variant[0].code; #  ↪︎ "aranese"

Most users will just want to use the main class, LanguageTag, but a common way to work with language tags is to filter them. There are two ways to do that. For filtering multiple values, you can use the sub `filter-language-tags`

my @tags = (
      LanguageTag.new('es-ES'),
      LanguageTag.new('es-MX'),
      LanguageTag.new('es-Latn-GQ'),
      LanguageTag.new('pt-GQ'),
    );

filter-language-tags: @tags, 'es';   #  ↪︎ [es-ES], [es-MX], [es-GQ]
    filter-language-tags: @tags, '*-GQ'; #  ↪︎ [es-GQ], [pt-GQ]

To check a single value, you can smart match on a filter object:

my $filter = LanguageTagFilter('*-Latf'); # 'in Fraktur script'

LanguageTag.new('de-Latf-DE') ~~ $filter # ↪︎ True
    LanguageTag.new('de-Latn-AU') ~~ $filter # ↪︎ False

The filtering is based on RFC4647 and is what you might expect in a HTTP request header. However, for the ambitious, the special LanguageTagFilter object provides for a good more flexibility and power than what you get from the basic `.new(Str)` if you create it programmatically.