nl_tokens: Validates the language tag . Section 2 . 2 . 9 of the bcp47 spec defines a valid tag .
pl_tokens: function isValidLanguageTag ( locale ) { // Check if it's well-formed, including grandfadered tags. if ( IS_NULL ( InternalRegExpMatch ( GetLanguageTagRE ( ) , locale ) ) ) { return false ; } // Just return if it's a x- form. It's all private. if ( % _Call ( StringIndexOf , locale , 'x-' ) === 0 ) { return true ; } // Check if there are any duplicate variants or singletons (extensions). // Remove private use section. locale = % _Call ( StringSplit , locale , '-x-' ) [ 0 ] ; // Skip language since it can match variant regex, so we start from 1. // We are matching i-klingon here, but that's ok, since i-klingon-klingon // is not valid and would fail LANGUAGE_TAG_RE test. var variants = new InternalArray ( ) ; var extensions = new InternalArray ( ) ; var parts = % _Call ( StringSplit , locale , '-' ) ; for ( var i = 1 ; i < parts . length ; i ++ ) { var value = parts [ i ] ; if ( ! IS_NULL ( InternalRegExpMatch ( GetLanguageVariantRE ( ) , value ) ) && extensions . length === 0 ) { if ( % _Call ( ArrayIndexOf , variants , value ) === - 1 ) { % _Call ( ArrayPush , variants , value ) ; } else { return false ; } } if ( ! IS_NULL ( InternalRegExpMatch ( GetLanguageSingletonRE ( ) , value ) ) ) { if ( % _Call ( ArrayIndexOf , extensions , value ) === - 1 ) { % _Call ( ArrayPush , extensions , value ) ; } else { return false ; } } } return <mask> ; }