Monster. I18n

Parse local according to rfc4646 standard

Limitations: The regex cannot handle multiple variants or private.

You can call the method via the monster namespace Monster.I18n.createLocale().

<script type="module">
import {Monster} from '@schukai/monster/source/monster.mjs';
new Monster.I18n.createLocale()
</script>

Alternatively, you can also integrate this function individually.

<script type="module">
import {createLocale} from '@schukai/monster/source/i18n/locale.mjs';
createLocale()
</script>

RFC

  The syntax of the language tag in ABNF [RFC4234] is:

  Language-Tag  = langtag
                / privateuse             ; private use tag
                / grandfathered          ; grandfathered registrations

  langtag       = (language
                   ["-" script]
                   ["-" region]
                   *("-" variant)
                   *("-" extension)
                   ["-" privateuse])

  language      = (2*3ALPHA [ extlang ]) ; shortest ISO 639 code
                / 4ALPHA                 ; reserved for future use
                / 5*8ALPHA               ; registered language subtag

  extlang       = *3("-" 3ALPHA)         ; reserved for future use

  script        = 4ALPHA                 ; ISO 15924 code

  region        = 2ALPHA                 ; ISO 3166 code
                / 3DIGIT                 ; UN M.49 code

  variant       = 5*8alphanum            ; registered variants
                / (DIGIT 3alphanum)

  extension     = singleton 1*("-" (2*8alphanum))

  singleton     = %x41-57 / %x59-5A / %x61-77 / %x79-7A / DIGIT
                ; "a"-"w" / "y"-"z" / "A"-"W" / "Y"-"Z" / "0"-"9"
                ; Single letters: x/X is reserved for private use

  privateuse    = ("x"/"X") 1*("-" (1*8alphanum))

  grandfathered = 1*3ALPHA 1*2("-" (2*8alphanum))
                  ; grandfathered registration
                  ; Note: i is the only singleton
                  ; that starts a grandfathered tag

  alphanum      = (ALPHA / DIGIT)       ; letters and numbers

                       Figure 1: Language Tag ABNF