Regional variants

A regional variant is translated as a set of departures from its parent language. A fr-CA segment without a usable target of its own takes the fr one; translators of Canadian French only write the segments that differ in Canada — courriel for e-mail, fin de semaine for week-end —, and every other segment reads as French.

Variants names the variants that inherit. By default they are fr-CA and en-CA; any other tag stands alone.

use Phil\TranslationMemory\LanguageTag;
use Phil\TranslationMemory\Variants;

$variants = new Variants();                          // fr-CA and en-CA
$variants = new Variants(['fr-CA', 'en-CA', 'pt-BR']);
$variants = Variants::none();                        // every language stands alone

$variants->parentOf(LanguageTag::of('fr-CA'));       // fr
$variants->chain(LanguageTag::of('fr-CA'));          // [fr-CA, fr]
$variants->variants();                               // ['fr-CA', 'en-CA']

A locale as Symfony writes it, fr_CA, is read by LanguageTag::fromLocale(). The parent of a tag is the tag without its last subtag: LanguageTag::of('fr-CA')->parent() is fr, zh-Hant-TW gives zh-Hant. A variant whose parent is itself a variant inherits along the chain, the nearest language winning. A primary language alone has no parent and is refused as a variant with InvalidLanguage.

Inheriting targets

inherit($own, $parent) gives the segments of a variant with the targets of its parent filled in:

• a segment of the variant that is translated or reviewed keeps its own target;
• one that is untranslated, suggested or stale — or missing — takes the parent's segment of the same key, when that one is translated or reviewed and was made from the same source, white space aside;
• the variant's own segments come first, in their order, then the parent's usable segments it lacks.

$french = $segmenter->assemble($document, $variants->inherit($canadianSegments, $frenchSegments));

For a longer chain, resolve from the farthest language in: the parent's segments given to inherit() are those of the parent already resolved against its own parent. phil/translation-bundle does this for the document a site publishes, and keeps the variant's own segments for the translators' screen.

The memory

TranslationMemory reads along the same chain: a lookup for fr-CA gives the fr-CA units and the fr units, best score first, and a fr-CA unit before a fr unit of the same score. The memory is given its Variants as its fifth argument, new Variants() by default. See Translation memory.